Merge branch 'tracing-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'tracing-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (241 commits)
  sched, trace: update trace_sched_wakeup()
  tracing/ftrace: don't trace on early stage of a secondary cpu boot, v3
  Revert "x86: disable X86_PTRACE_BTS"
  ring-buffer: prevent false positive warning
  ring-buffer: fix dangling commit race
  ftrace: enable format arguments checking
  x86, bts: memory accounting
  x86, bts: add fork and exit handling
  ftrace: introduce tracing_reset_online_cpus() helper
  tracing: fix warnings in kernel/trace/trace_sched_switch.c
  tracing: fix warning in kernel/trace/trace.c
  tracing/ring-buffer: remove unused ring_buffer size
  trace: fix task state printout
  ftrace: add not to regex on filtering functions
  trace: better use of stack_trace_enabled for boot up code
  trace: add a way to enable or disable the stack tracer
  x86: entry_64 - introduce FTRACE_ frame macro v2
  tracing/ftrace: add the printk-msg-only option
  tracing/ftrace: use preempt_enable_no_resched_notrace in ring_buffer_time_stamp()
  x86, bts: correctly report invalid bts records
  ...

Fixed up trivial conflict in scripts/recordmcount.pl due to SH bits
being already partly merged by the SH merge.

20 files changed, 4400 insertions, 802 deletions

diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig
index 33dbefd..e2a4ff6 100644
--- a/kernel/trace/Kconfig
+++ b/kernel/trace/Kconfig
@@ -3,18 +3,34 @@
 #  select HAVE_FUNCTION_TRACER:
 #
 
+config USER_STACKTRACE_SUPPORT
+	bool
+
 config NOP_TRACER
 	bool
 
 config HAVE_FUNCTION_TRACER
 	bool
 
+config HAVE_FUNCTION_GRAPH_TRACER
+	bool
+
+config HAVE_FUNCTION_TRACE_MCOUNT_TEST
+	bool
+	help
+	 This gets selected when the arch tests the function_trace_stop
+	 variable at the mcount call site. Otherwise, this variable
+	 is tested by the called function.
+
 config HAVE_DYNAMIC_FTRACE
 	bool
 
 config HAVE_FTRACE_MCOUNT_RECORD
 	bool
 
+config HAVE_HW_BRANCH_TRACER
+	bool
+
 config TRACER_MAX_TRACE
 	bool
 
@@ -47,6 +63,20 @@ config FUNCTION_TRACER
 	  (the bootup default), then the overhead of the instructions is very
 	  small and not measurable even in micro-benchmarks.
 
+config FUNCTION_GRAPH_TRACER
+	bool "Kernel Function Graph Tracer"
+	depends on HAVE_FUNCTION_GRAPH_TRACER
+	depends on FUNCTION_TRACER
+	default y
+	help
+	  Enable the kernel to trace a function at both its return
+	  and its entry.
+	  It's first purpose is to trace the duration of functions and
+	  draw a call graph for each thread with some informations like
+	  the return value.
+	  This is done by setting the current return address on the current
+	  task structure into a stack of calls.
+
 config IRQSOFF_TRACER
 	bool "Interrupts-off Latency Tracer"
 	default n
@@ -138,6 +168,70 @@ config BOOT_TRACER
 	    selected, because the self-tests are an initcall as well and that
 	    would invalidate the boot trace. )
 
+config TRACE_BRANCH_PROFILING
+	bool "Trace likely/unlikely profiler"
+	depends on DEBUG_KERNEL
+	select TRACING
+	help
+	  This tracer profiles all the the likely and unlikely macros
+	  in the kernel. It will display the results in:
+
+	  /debugfs/tracing/profile_annotated_branch
+
+	  Note: this will add a significant overhead, only turn this
+	  on if you need to profile the system's use of these macros.
+
+	  Say N if unsure.
+
+config PROFILE_ALL_BRANCHES
+	bool "Profile all if conditionals"
+	depends on TRACE_BRANCH_PROFILING
+	help
+	  This tracer profiles all branch conditions. Every if ()
+	  taken in the kernel is recorded whether it hit or miss.
+	  The results will be displayed in:
+
+	  /debugfs/tracing/profile_branch
+
+	  This configuration, when enabled, will impose a great overhead
+	  on the system. This should only be enabled when the system
+	  is to be analyzed
+
+	  Say N if unsure.
+
+config TRACING_BRANCHES
+	bool
+	help
+	  Selected by tracers that will trace the likely and unlikely
+	  conditions. This prevents the tracers themselves from being
+	  profiled. Profiling the tracing infrastructure can only happen
+	  when the likelys and unlikelys are not being traced.
+
+config BRANCH_TRACER
+	bool "Trace likely/unlikely instances"
+	depends on TRACE_BRANCH_PROFILING
+	select TRACING_BRANCHES
+	help
+	  This traces the events of likely and unlikely condition
+	  calls in the kernel.  The difference between this and the
+	  "Trace likely/unlikely profiler" is that this is not a
+	  histogram of the callers, but actually places the calling
+	  events into a running trace buffer to see when and where the
+	  events happened, as well as their results.
+
+	  Say N if unsure.
+
+config POWER_TRACER
+	bool "Trace power consumption behavior"
+	depends on DEBUG_KERNEL
+	depends on X86
+	select TRACING
+	help
+	  This tracer helps developers to analyze and optimize the kernels
+	  power management decisions, specifically the C-state and P-state
+	  behavior.
+
+
 config STACK_TRACER
 	bool "Trace max stack"
 	depends on HAVE_FUNCTION_TRACER
@@ -150,13 +244,26 @@ config STACK_TRACER
 
 	  This tracer works by hooking into every function call that the
 	  kernel executes, and keeping a maximum stack depth value and
-	  stack-trace saved. Because this logic has to execute in every
-	  kernel function, all the time, this option can slow down the
-	  kernel measurably and is generally intended for kernel
-	  developers only.
+	  stack-trace saved.  If this is configured with DYNAMIC_FTRACE
+	  then it will not have any overhead while the stack tracer
+	  is disabled.
+
+	  To enable the stack tracer on bootup, pass in 'stacktrace'
+	  on the kernel command line.
+
+	  The stack tracer can also be enabled or disabled via the
+	  sysctl kernel.stack_tracer_enabled
 
 	  Say N if unsure.
 
+config HW_BRANCH_TRACER
+	depends on HAVE_HW_BRANCH_TRACER
+	bool "Trace hw branches"
+	select TRACING
+	help
+	  This tracer records all branches on the system in a circular
+	  buffer giving access to the last N branches for each cpu.
+
 config DYNAMIC_FTRACE
 	bool "enable/disable ftrace tracepoints dynamically"
 	depends on FUNCTION_TRACER
diff --git a/kernel/trace/Makefile b/kernel/trace/Makefile
index c8228b1..349d5a9 100644
--- a/kernel/trace/Makefile
+++ b/kernel/trace/Makefile
@@ -10,6 +10,11 @@ CFLAGS_trace_selftest_dynamic.o = -pg
 obj-y += trace_selftest_dynamic.o
 endif
 
+# If unlikely tracing is enabled, do not trace these files
+ifdef CONFIG_TRACING_BRANCHES
+KBUILD_CFLAGS += -DDISABLE_BRANCH_PROFILING
+endif
+
 obj-$(CONFIG_FUNCTION_TRACER) += libftrace.o
 obj-$(CONFIG_RING_BUFFER) += ring_buffer.o
 
@@ -24,5 +29,9 @@ obj-$(CONFIG_NOP_TRACER) += trace_nop.o
 obj-$(CONFIG_STACK_TRACER) += trace_stack.o
 obj-$(CONFIG_MMIOTRACE) += trace_mmiotrace.o
 obj-$(CONFIG_BOOT_TRACER) += trace_boot.o
+obj-$(CONFIG_FUNCTION_GRAPH_TRACER) += trace_functions_graph.o
+obj-$(CONFIG_TRACE_BRANCH_PROFILING) += trace_branch.o
+obj-$(CONFIG_HW_BRANCH_TRACER) += trace_hw_branches.o
+obj-$(CONFIG_POWER_TRACER) += trace_power.o
 
 libftrace-y := ftrace.o
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 78db083..2f32969 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -47,6 +47,13 @@
 int ftrace_enabled __read_mostly;
 static int last_ftrace_enabled;
 
+/* set when tracing only a pid */
+struct pid *ftrace_pid_trace;
+static struct pid * const ftrace_swapper_pid = &init_struct_pid;
+
+/* Quick disabling of function tracer. */
+int function_trace_stop;
+
 /*
  * ftrace_disabled is set when an anomaly is discovered.
  * ftrace_disabled is much stronger than ftrace_enabled.
@@ -55,6 +62,7 @@ static int ftrace_disabled __read_mostly;
 
 static DEFINE_SPINLOCK(ftrace_lock);
 static DEFINE_MUTEX(ftrace_sysctl_lock);
+static DEFINE_MUTEX(ftrace_start_lock);
 
 static struct ftrace_ops ftrace_list_end __read_mostly =
 {
@@ -63,6 +71,8 @@ static struct ftrace_ops ftrace_list_end __read_mostly =
 
 static struct ftrace_ops *ftrace_list __read_mostly = &ftrace_list_end;
 ftrace_func_t ftrace_trace_function __read_mostly = ftrace_stub;
+ftrace_func_t __ftrace_trace_function __read_mostly = ftrace_stub;
+ftrace_func_t ftrace_pid_function __read_mostly = ftrace_stub;
 
 static void ftrace_list_func(unsigned long ip, unsigned long parent_ip)
 {
@@ -79,6 +89,21 @@ static void ftrace_list_func(unsigned long ip, unsigned long parent_ip)
 	};
 }
 
+static void ftrace_pid_func(unsigned long ip, unsigned long parent_ip)
+{
+	if (!test_tsk_trace_trace(current))
+		return;
+
+	ftrace_pid_function(ip, parent_ip);
+}
+
+static void set_ftrace_pid_function(ftrace_func_t func)
+{
+	/* do not set ftrace_pid_function to itself! */
+	if (func != ftrace_pid_func)
+		ftrace_pid_function = func;
+}
+
 /**
  * clear_ftrace_function - reset the ftrace function
  *
@@ -88,7 +113,23 @@ static void ftrace_list_func(unsigned long ip, unsigned long parent_ip)
 void clear_ftrace_function(void)
 {
 	ftrace_trace_function = ftrace_stub;
+	__ftrace_trace_function = ftrace_stub;
+	ftrace_pid_function = ftrace_stub;
+}
+
+#ifndef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST
+/*
+ * For those archs that do not test ftrace_trace_stop in their
+ * mcount call site, we need to do it from C.
+ */
+static void ftrace_test_stop_func(unsigned long ip, unsigned long parent_ip)
+{
+	if (function_trace_stop)
+		return;
+
+	__ftrace_trace_function(ip, parent_ip);
 }
+#endif
 
 static int __register_ftrace_function(struct ftrace_ops *ops)
 {
@@ -106,14 +147,28 @@ static int __register_ftrace_function(struct ftrace_ops *ops)
 	ftrace_list = ops;
 
 	if (ftrace_enabled) {
+		ftrace_func_t func;
+
+		if (ops->next == &ftrace_list_end)
+			func = ops->func;
+		else
+			func = ftrace_list_func;
+
+		if (ftrace_pid_trace) {
+			set_ftrace_pid_function(func);
+			func = ftrace_pid_func;
+		}
+
 		/*
 		 * For one func, simply call it directly.
 		 * For more than one func, call the chain.
 		 */
-		if (ops->next == &ftrace_list_end)
-			ftrace_trace_function = ops->func;
-		else
-			ftrace_trace_function = ftrace_list_func;
+#ifdef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST
+		ftrace_trace_function = func;
+#else
+		__ftrace_trace_function = func;
+		ftrace_trace_function = ftrace_test_stop_func;
+#endif
 	}
 
 	spin_unlock(&ftrace_lock);
@@ -152,9 +207,19 @@ static int __unregister_ftrace_function(struct ftrace_ops *ops)
 
 	if (ftrace_enabled) {
 		/* If we only have one func left, then call that directly */
-		if (ftrace_list == &ftrace_list_end ||
-		    ftrace_list->next == &ftrace_list_end)
-			ftrace_trace_function = ftrace_list->func;
+		if (ftrace_list->next == &ftrace_list_end) {
+			ftrace_func_t func = ftrace_list->func;
+
+			if (ftrace_pid_trace) {
+				set_ftrace_pid_function(func);
+				func = ftrace_pid_func;
+			}
+#ifdef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST
+			ftrace_trace_function = func;
+#else
+			__ftrace_trace_function = func;
+#endif
+		}
 	}
 
  out:
@@ -163,6 +228,36 @@ static int __unregister_ftrace_function(struct ftrace_ops *ops)
 	return ret;
 }
 
+static void ftrace_update_pid_func(void)
+{
+	ftrace_func_t func;
+
+	/* should not be called from interrupt context */
+	spin_lock(&ftrace_lock);
+
+	if (ftrace_trace_function == ftrace_stub)
+		goto out;
+
+	func = ftrace_trace_function;
+
+	if (ftrace_pid_trace) {
+		set_ftrace_pid_function(func);
+		func = ftrace_pid_func;
+	} else {
+		if (func == ftrace_pid_func)
+			func = ftrace_pid_function;
+	}
+
+#ifdef CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST
+	ftrace_trace_function = func;
+#else
+	__ftrace_trace_function = func;
+#endif
+
+ out:
+	spin_unlock(&ftrace_lock);
+}
+
 #ifdef CONFIG_DYNAMIC_FTRACE
 #ifndef CONFIG_FTRACE_MCOUNT_RECORD
 # error Dynamic ftrace depends on MCOUNT_RECORD
@@ -182,6 +277,8 @@ enum {
 	FTRACE_UPDATE_TRACE_FUNC	= (1 << 2),
 	FTRACE_ENABLE_MCOUNT		= (1 << 3),
 	FTRACE_DISABLE_MCOUNT		= (1 << 4),
+	FTRACE_START_FUNC_RET		= (1 << 5),
+	FTRACE_STOP_FUNC_RET		= (1 << 6),
 };
 
 static int ftrace_filtered;
@@ -308,7 +405,7 @@ ftrace_record_ip(unsigned long ip)
 {
 	struct dyn_ftrace *rec;
 
-	if (!ftrace_enabled || ftrace_disabled)
+	if (ftrace_disabled)
 		return NULL;
 
 	rec = ftrace_alloc_dyn_node(ip);
@@ -322,14 +419,51 @@ ftrace_record_ip(unsigned long ip)
 	return rec;
 }
 
-#define FTRACE_ADDR ((long)(ftrace_caller))
+static void print_ip_ins(const char *fmt, unsigned char *p)
+{
+	int i;
+
+	printk(KERN_CONT "%s", fmt);
+
+	for (i = 0; i < MCOUNT_INSN_SIZE; i++)
+		printk(KERN_CONT "%s%02x", i ? ":" : "", p[i]);
+}
+
+static void ftrace_bug(int failed, unsigned long ip)
+{
+	switch (failed) {
+	case -EFAULT:
+		FTRACE_WARN_ON_ONCE(1);
+		pr_info("ftrace faulted on modifying ");
+		print_ip_sym(ip);
+		break;
+	case -EINVAL:
+		FTRACE_WARN_ON_ONCE(1);
+		pr_info("ftrace failed to modify ");
+		print_ip_sym(ip);
+		print_ip_ins(" actual: ", (unsigned char *)ip);
+		printk(KERN_CONT "\n");
+		break;
+	case -EPERM:
+		FTRACE_WARN_ON_ONCE(1);
+		pr_info("ftrace faulted on writing ");
+		print_ip_sym(ip);
+		break;
+	default:
+		FTRACE_WARN_ON_ONCE(1);
+		pr_info("ftrace faulted on unknown error ");
+		print_ip_sym(ip);
+	}
+}
+
 
 static int
-__ftrace_replace_code(struct dyn_ftrace *rec,
-		      unsigned char *nop, int enable)
+__ftrace_replace_code(struct dyn_ftrace *rec, int enable)
 {
 	unsigned long ip, fl;
-	unsigned char *call, *old, *new;
+	unsigned long ftrace_addr;
+
+	ftrace_addr = (unsigned long)ftrace_caller;
 
 	ip = rec->ip;
 
@@ -388,34 +522,28 @@ __ftrace_replace_code(struct dyn_ftrace *rec,
 		}
 	}
 
-	call = ftrace_call_replace(ip, FTRACE_ADDR);
-
-	if (rec->flags & FTRACE_FL_ENABLED) {
-		old = nop;
-		new = call;
-	} else {
-		old = call;
-		new = nop;
-	}
-
-	return ftrace_modify_code(ip, old, new);
+	if (rec->flags & FTRACE_FL_ENABLED)
+		return ftrace_make_call(rec, ftrace_addr);
+	else
+		return ftrace_make_nop(NULL, rec, ftrace_addr);
 }
 
 static void ftrace_replace_code(int enable)
 {
 	int i, failed;
-	unsigned char *nop = NULL;
 	struct dyn_ftrace *rec;
 	struct ftrace_page *pg;
 
-	nop = ftrace_nop_replace();
-
 	for (pg = ftrace_pages_start; pg; pg = pg->next) {
 		for (i = 0; i < pg->index; i++) {
 			rec = &pg->records[i];
 
-			/* don't modify code that has already faulted */
-			if (rec->flags & FTRACE_FL_FAILED)
+			/*
+			 * Skip over free records and records that have
+			 * failed.
+			 */
+			if (rec->flags & FTRACE_FL_FREE ||
+			    rec->flags & FTRACE_FL_FAILED)
 				continue;
 
 			/* ignore updates to this record's mcount site */
@@ -426,68 +554,30 @@ static void ftrace_replace_code(int enable)
 				unfreeze_record(rec);
 			}
 
-			failed = __ftrace_replace_code(rec, nop, enable);
+			failed = __ftrace_replace_code(rec, enable);
 			if (failed && (rec->flags & FTRACE_FL_CONVERTED)) {
 				rec->flags |= FTRACE_FL_FAILED;
 				if ((system_state == SYSTEM_BOOTING) ||
 				    !core_kernel_text(rec->ip)) {
 					ftrace_free_rec(rec);
-				}
+				} else
+					ftrace_bug(failed, rec->ip);
 			}
 		}
 	}
 }
 
-static void print_ip_ins(const char *fmt, unsigned char *p)
-{
-	int i;
-
-	printk(KERN_CONT "%s", fmt);
-
-	for (i = 0; i < MCOUNT_INSN_SIZE; i++)
-		printk(KERN_CONT "%s%02x", i ? ":" : "", p[i]);
-}
-
 static int
-ftrace_code_disable(struct dyn_ftrace *rec)
+ftrace_code_disable(struct module *mod, struct dyn_ftrace *rec)
 {
 	unsigned long ip;
-	unsigned char *nop, *call;
 	int ret;
 
 	ip = rec->ip;
 
-	nop = ftrace_nop_replace();
-	call = ftrace_call_replace(ip, mcount_addr);
-
-	ret = ftrace_modify_code(ip, call, nop);
+	ret = ftrace_make_nop(mod, rec, mcount_addr);
 	if (ret) {
-		switch (ret) {
-		case -EFAULT:
-			FTRACE_WARN_ON_ONCE(1);
-			pr_info("ftrace faulted on modifying ");
-			print_ip_sym(ip);
-			break;
-		case -EINVAL:
-			FTRACE_WARN_ON_ONCE(1);
-			pr_info("ftrace failed to modify ");
-			print_ip_sym(ip);
-			print_ip_ins(" expected: ", call);
-			print_ip_ins(" actual: ", (unsigned char *)ip);
-			print_ip_ins(" replace: ", nop);
-			printk(KERN_CONT "\n");
-			break;
-		case -EPERM:
-			FTRACE_WARN_ON_ONCE(1);
-			pr_info("ftrace faulted on writing ");
-			print_ip_sym(ip);
-			break;
-		default:
-			FTRACE_WARN_ON_ONCE(1);
-			pr_info("ftrace faulted on unknown error ");
-			print_ip_sym(ip);
-		}
-
+		ftrace_bug(ret, ip);
 		rec->flags |= FTRACE_FL_FAILED;
 		return 0;
 	}
@@ -506,6 +596,11 @@ static int __ftrace_modify_code(void *data)
 	if (*command & FTRACE_UPDATE_TRACE_FUNC)
 		ftrace_update_ftrace_func(ftrace_trace_function);
 
+	if (*command & FTRACE_START_FUNC_RET)
+		ftrace_enable_ftrace_graph_caller();
+	else if (*command & FTRACE_STOP_FUNC_RET)
+		ftrace_disable_ftrace_graph_caller();
+
 	return 0;
 }
 
@@ -515,43 +610,43 @@ static void ftrace_run_update_code(int command)
 }
 
 static ftrace_func_t saved_ftrace_func;
-static int ftrace_start;
-static DEFINE_MUTEX(ftrace_start_lock);
+static int ftrace_start_up;
 
-static void ftrace_startup(void)
+static void ftrace_startup_enable(int command)
 {
-	int command = 0;
-
-	if (unlikely(ftrace_disabled))
-		return;
-
-	mutex_lock(&ftrace_start_lock);
-	ftrace_start++;
-	command |= FTRACE_ENABLE_CALLS;
-
 	if (saved_ftrace_func != ftrace_trace_function) {
 		saved_ftrace_func = ftrace_trace_function;
 		command |= FTRACE_UPDATE_TRACE_FUNC;
 	}
 
 	if (!command || !ftrace_enabled)
-		goto out;
+		return;
 
 	ftrace_run_update_code(command);
- out:
-	mutex_unlock(&ftrace_start_lock);
 }
 
-static void ftrace_shutdown(void)
+static void ftrace_startup(int command)
 {
-	int command = 0;
+	if (unlikely(ftrace_disabled))
+		return;
+
+	mutex_lock(&ftrace_start_lock);
+	ftrace_start_up++;
+	command |= FTRACE_ENABLE_CALLS;
 
+	ftrace_startup_enable(command);
+
+	mutex_unlock(&ftrace_start_lock);
+}
+
+static void ftrace_shutdown(int command)
+{
 	if (unlikely(ftrace_disabled))
 		return;
 
 	mutex_lock(&ftrace_start_lock);
-	ftrace_start--;
-	if (!ftrace_start)
+	ftrace_start_up--;
+	if (!ftrace_start_up)
 		command |= FTRACE_DISABLE_CALLS;
 
 	if (saved_ftrace_func != ftrace_trace_function) {
@@ -577,8 +672,8 @@ static void ftrace_startup_sysctl(void)
 	mutex_lock(&ftrace_start_lock);
 	/* Force update next time */
 	saved_ftrace_func = NULL;
-	/* ftrace_start is true if we want ftrace running */
-	if (ftrace_start)
+	/* ftrace_start_up is true if we want ftrace running */
+	if (ftrace_start_up)
 		command |= FTRACE_ENABLE_CALLS;
 
 	ftrace_run_update_code(command);
@@ -593,8 +688,8 @@ static void ftrace_shutdown_sysctl(void)
 		return;
 
 	mutex_lock(&ftrace_start_lock);
-	/* ftrace_start is true if ftrace is running */
-	if (ftrace_start)
+	/* ftrace_start_up is true if ftrace is running */
+	if (ftrace_start_up)
 		command |= FTRACE_DISABLE_CALLS;
 
 	ftrace_run_update_code(command);
@@ -605,7 +700,7 @@ static cycle_t		ftrace_update_time;
 static unsigned long	ftrace_update_cnt;
 unsigned long		ftrace_update_tot_cnt;
 
-static int ftrace_update_code(void)
+static int ftrace_update_code(struct module *mod)
 {
 	struct dyn_ftrace *p, *t;
 	cycle_t start, stop;
@@ -622,7 +717,7 @@ static int ftrace_update_code(void)
 		list_del_init(&p->list);
 
 		/* convert record (i.e, patch mcount-call with NOP) */
-		if (ftrace_code_disable(p)) {
+		if (ftrace_code_disable(mod, p)) {
 			p->flags |= FTRACE_FL_CONVERTED;
 			ftrace_update_cnt++;
 		} else
@@ -690,7 +785,6 @@ enum {
 #define FTRACE_BUFF_MAX (KSYM_SYMBOL_LEN+4) /* room for wildcards */
 
 struct ftrace_iterator {
-	loff_t			pos;
 	struct ftrace_page	*pg;
 	unsigned		idx;
 	unsigned		flags;
@@ -715,6 +809,8 @@ t_next(struct seq_file *m, void *v, loff_t *pos)
 			iter->pg = iter->pg->next;
 			iter->idx = 0;
 			goto retry;
+		} else {
+			iter->idx = -1;
 		}
 	} else {
 		rec = &iter->pg->records[iter->idx++];
@@ -737,8 +833,6 @@ t_next(struct seq_file *m, void *v, loff_t *pos)
 	}
 	spin_unlock(&ftrace_lock);
 
-	iter->pos = *pos;
-
 	return rec;
 }
 
@@ -746,13 +840,15 @@ static void *t_start(struct seq_file *m, loff_t *pos)
 {
 	struct ftrace_iterator *iter = m->private;
 	void *p = NULL;
-	loff_t l = -1;
 
-	if (*pos > iter->pos)
-		*pos = iter->pos;
+	if (*pos > 0) {
+		if (iter->idx < 0)
+			return p;
+		(*pos)--;
+		iter->idx--;
+	}
 
-	l = *pos;
-	p = t_next(m, p, &l);
+	p = t_next(m, p, pos);
 
 	return p;
 }
@@ -763,21 +859,15 @@ static void t_stop(struct seq_file *m, void *p)
 
 static int t_show(struct seq_file *m, void *v)
 {
-	struct ftrace_iterator *iter = m->private;
 	struct dyn_ftrace *rec = v;
 	char str[KSYM_SYMBOL_LEN];
-	int ret = 0;
 
 	if (!rec)
 		return 0;
 
 	kallsyms_lookup(rec->ip, NULL, NULL, NULL, str);
 
-	ret = seq_printf(m, "%s\n", str);
-	if (ret < 0) {
-		iter->pos--;
-		iter->idx--;
-	}
+	seq_printf(m, "%s\n", str);
 
 	return 0;
 }
@@ -803,7 +893,6 @@ ftrace_avail_open(struct inode *inode, struct file *file)
 		return -ENOMEM;
 
 	iter->pg = ftrace_pages_start;
-	iter->pos = 0;
 
 	ret = seq_open(file, &show_ftrace_seq_ops);
 	if (!ret) {
@@ -890,7 +979,6 @@ ftrace_regex_open(struct inode *inode, struct file *file, int enable)
 
 	if (file->f_mode & FMODE_READ) {
 		iter->pg = ftrace_pages_start;
-		iter->pos = 0;
 		iter->flags = enable ? FTRACE_ITER_FILTER :
 			FTRACE_ITER_NOTRACE;
 
@@ -959,6 +1047,13 @@ ftrace_match(unsigned char *buff, int len, int enable)
 	int type = MATCH_FULL;
 	unsigned long flag = enable ? FTRACE_FL_FILTER : FTRACE_FL_NOTRACE;
 	unsigned i, match = 0, search_len = 0;
+	int not = 0;
+
+	if (buff[0] == '!') {
+		not = 1;
+		buff++;
+		len--;
+	}
 
 	for (i = 0; i < len; i++) {
 		if (buff[i] == '*') {
@@ -1012,8 +1107,12 @@ ftrace_match(unsigned char *buff, int len, int enable)
 					matched = 1;
 				break;
 			}
-			if (matched)
-				rec->flags |= flag;
+			if (matched) {
+				if (not)
+					rec->flags &= ~flag;
+				else
+					rec->flags |= flag;
+			}
 		}
 		pg = pg->next;
 	}
@@ -1181,7 +1280,7 @@ ftrace_regex_release(struct inode *inode, struct file *file, int enable)
 
 	mutex_lock(&ftrace_sysctl_lock);
 	mutex_lock(&ftrace_start_lock);
-	if (ftrace_start && ftrace_enabled)
+	if (ftrace_start_up && ftrace_enabled)
 		ftrace_run_update_code(FTRACE_ENABLE_CALLS);
 	mutex_unlock(&ftrace_start_lock);
 	mutex_unlock(&ftrace_sysctl_lock);
@@ -1233,12 +1332,233 @@ static struct file_operations ftrace_notrace_fops = {
 	.release = ftrace_notrace_release,
 };
 
-static __init int ftrace_init_debugfs(void)
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+
+static DEFINE_MUTEX(graph_lock);
+
+int ftrace_graph_count;
+unsigned long ftrace_graph_funcs[FTRACE_GRAPH_MAX_FUNCS] __read_mostly;
+
+static void *
+g_next(struct seq_file *m, void *v, loff_t *pos)
 {
-	struct dentry *d_tracer;
-	struct dentry *entry;
+	unsigned long *array = m->private;
+	int index = *pos;
 
-	d_tracer = tracing_init_dentry();
+	(*pos)++;
+
+	if (index >= ftrace_graph_count)
+		return NULL;
+
+	return &array[index];
+}
+
+static void *g_start(struct seq_file *m, loff_t *pos)
+{
+	void *p = NULL;
+
+	mutex_lock(&graph_lock);
+
+	p = g_next(m, p, pos);
+
+	return p;
+}
+
+static void g_stop(struct seq_file *m, void *p)
+{
+	mutex_unlock(&graph_lock);
+}
+
+static int g_show(struct seq_file *m, void *v)
+{
+	unsigned long *ptr = v;
+	char str[KSYM_SYMBOL_LEN];
+
+	if (!ptr)
+		return 0;
+
+	kallsyms_lookup(*ptr, NULL, NULL, NULL, str);
+
+	seq_printf(m, "%s\n", str);
+
+	return 0;
+}
+
+static struct seq_operations ftrace_graph_seq_ops = {
+	.start = g_start,
+	.next = g_next,
+	.stop = g_stop,
+	.show = g_show,
+};
+
+static int
+ftrace_graph_open(struct inode *inode, struct file *file)
+{
+	int ret = 0;
+
+	if (unlikely(ftrace_disabled))
+		return -ENODEV;
+
+	mutex_lock(&graph_lock);
+	if ((file->f_mode & FMODE_WRITE) &&
+	    !(file->f_flags & O_APPEND)) {
+		ftrace_graph_count = 0;
+		memset(ftrace_graph_funcs, 0, sizeof(ftrace_graph_funcs));
+	}
+
+	if (file->f_mode & FMODE_READ) {
+		ret = seq_open(file, &ftrace_graph_seq_ops);
+		if (!ret) {
+			struct seq_file *m = file->private_data;
+			m->private = ftrace_graph_funcs;
+		}
+	} else
+		file->private_data = ftrace_graph_funcs;
+	mutex_unlock(&graph_lock);
+
+	return ret;
+}
+
+static ssize_t
+ftrace_graph_read(struct file *file, char __user *ubuf,
+		       size_t cnt, loff_t *ppos)
+{
+	if (file->f_mode & FMODE_READ)
+		return seq_read(file, ubuf, cnt, ppos);
+	else
+		return -EPERM;
+}
+
+static int
+ftrace_set_func(unsigned long *array, int idx, char *buffer)
+{
+	char str[KSYM_SYMBOL_LEN];
+	struct dyn_ftrace *rec;
+	struct ftrace_page *pg;
+	int found = 0;
+	int i, j;
+
+	if (ftrace_disabled)
+		return -ENODEV;
+
+	/* should not be called from interrupt context */
+	spin_lock(&ftrace_lock);
+
+	for (pg = ftrace_pages_start; pg; pg = pg->next) {
+		for (i = 0; i < pg->index; i++) {
+			rec = &pg->records[i];
+
+			if (rec->flags & (FTRACE_FL_FAILED | FTRACE_FL_FREE))
+				continue;
+
+			kallsyms_lookup(rec->ip, NULL, NULL, NULL, str);
+			if (strcmp(str, buffer) == 0) {
+				found = 1;
+				for (j = 0; j < idx; j++)
+					if (array[j] == rec->ip) {
+						found = 0;
+						break;
+					}
+				if (found)
+					array[idx] = rec->ip;
+				break;
+			}
+		}
+	}
+	spin_unlock(&ftrace_lock);
+
+	return found ? 0 : -EINVAL;
+}
+
+static ssize_t
+ftrace_graph_write(struct file *file, const char __user *ubuf,
+		   size_t cnt, loff_t *ppos)
+{
+	unsigned char buffer[FTRACE_BUFF_MAX+1];
+	unsigned long *array;
+	size_t read = 0;
+	ssize_t ret;
+	int index = 0;
+	char ch;
+
+	if (!cnt || cnt < 0)
+		return 0;
+
+	mutex_lock(&graph_lock);
+
+	if (ftrace_graph_count >= FTRACE_GRAPH_MAX_FUNCS) {
+		ret = -EBUSY;
+		goto out;
+	}
+
+	if (file->f_mode & FMODE_READ) {
+		struct seq_file *m = file->private_data;
+		array = m->private;
+	} else
+		array = file->private_data;
+
+	ret = get_user(ch, ubuf++);
+	if (ret)
+		goto out;
+	read++;
+	cnt--;
+
+	/* skip white space */
+	while (cnt && isspace(ch)) {
+		ret = get_user(ch, ubuf++);
+		if (ret)
+			goto out;
+		read++;
+		cnt--;
+	}
+
+	if (isspace(ch)) {
+		*ppos += read;
+		ret = read;
+		goto out;
+	}
+
+	while (cnt && !isspace(ch)) {
+		if (index < FTRACE_BUFF_MAX)
+			buffer[index++] = ch;
+		else {
+			ret = -EINVAL;
+			goto out;
+		}
+		ret = get_user(ch, ubuf++);
+		if (ret)
+			goto out;
+		read++;
+		cnt--;
+	}
+	buffer[index] = 0;
+
+	/* we allow only one at a time */
+	ret = ftrace_set_func(array, ftrace_graph_count, buffer);
+	if (ret)
+		goto out;
+
+	ftrace_graph_count++;
+
+	file->f_pos += read;
+
+	ret = read;
+ out:
+	mutex_unlock(&graph_lock);
+
+	return ret;
+}
+
+static const struct file_operations ftrace_graph_fops = {
+	.open = ftrace_graph_open,
+	.read = ftrace_graph_read,
+	.write = ftrace_graph_write,
+};
+#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
+
+static __init int ftrace_init_dyn_debugfs(struct dentry *d_tracer)
+{
+	struct dentry *entry;
 
 	entry = debugfs_create_file("available_filter_functions", 0444,
 				    d_tracer, NULL, &ftrace_avail_fops);
@@ -1263,12 +1583,20 @@ static __init int ftrace_init_debugfs(void)
 		pr_warning("Could not create debugfs "
 			   "'set_ftrace_notrace' entry\n");
 
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+	entry = debugfs_create_file("set_graph_function", 0444, d_tracer,
+				    NULL,
+				    &ftrace_graph_fops);
+	if (!entry)
+		pr_warning("Could not create debugfs "
+			   "'set_graph_function' entry\n");
+#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
+
 	return 0;
 }
 
-fs_initcall(ftrace_init_debugfs);
-
-static int ftrace_convert_nops(unsigned long *start,
+static int ftrace_convert_nops(struct module *mod,
+			       unsigned long *start,
 			       unsigned long *end)
 {
 	unsigned long *p;
@@ -1279,23 +1607,32 @@ static int ftrace_convert_nops(unsigned long *start,
 	p = start;
 	while (p < end) {
 		addr = ftrace_call_adjust(*p++);
+		/*
+		 * Some architecture linkers will pad between
+		 * the different mcount_loc sections of different
+		 * object files to satisfy alignments.
+		 * Skip any NULL pointers.
+		 */
+		if (!addr)
+			continue;
 		ftrace_record_ip(addr);
 	}
 
 	/* disable interrupts to prevent kstop machine */
 	local_irq_save(flags);
-	ftrace_update_code();
+	ftrace_update_code(mod);
 	local_irq_restore(flags);
 	mutex_unlock(&ftrace_start_lock);
 
 	return 0;
 }
 
-void ftrace_init_module(unsigned long *start, unsigned long *end)
+void ftrace_init_module(struct module *mod,
+			unsigned long *start, unsigned long *end)
 {
 	if (ftrace_disabled || start == end)
 		return;
-	ftrace_convert_nops(start, end);
+	ftrace_convert_nops(mod, start, end);
 }
 
 extern unsigned long __start_mcount_loc[];
@@ -1325,7 +1662,8 @@ void __init ftrace_init(void)
 
 	last_ftrace_enabled = ftrace_enabled = 1;
 
-	ret = ftrace_convert_nops(__start_mcount_loc,
+	ret = ftrace_convert_nops(NULL,
+				  __start_mcount_loc,
 				  __stop_mcount_loc);
 
 	return;
@@ -1342,12 +1680,186 @@ static int __init ftrace_nodyn_init(void)
 }
 device_initcall(ftrace_nodyn_init);
 
-# define ftrace_startup()		do { } while (0)
-# define ftrace_shutdown()		do { } while (0)
+static inline int ftrace_init_dyn_debugfs(struct dentry *d_tracer) { return 0; }
+static inline void ftrace_startup_enable(int command) { }
+/* Keep as macros so we do not need to define the commands */
+# define ftrace_startup(command)	do { } while (0)
+# define ftrace_shutdown(command)	do { } while (0)
 # define ftrace_startup_sysctl()	do { } while (0)
 # define ftrace_shutdown_sysctl()	do { } while (0)
 #endif /* CONFIG_DYNAMIC_FTRACE */
 
+static ssize_t
+ftrace_pid_read(struct file *file, char __user *ubuf,
+		       size_t cnt, loff_t *ppos)
+{
+	char buf[64];
+	int r;
+
+	if (ftrace_pid_trace == ftrace_swapper_pid)
+		r = sprintf(buf, "swapper tasks\n");
+	else if (ftrace_pid_trace)
+		r = sprintf(buf, "%u\n", pid_nr(ftrace_pid_trace));
+	else
+		r = sprintf(buf, "no pid\n");
+
+	return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
+}
+
+static void clear_ftrace_swapper(void)
+{
+	struct task_struct *p;
+	int cpu;
+
+	get_online_cpus();
+	for_each_online_cpu(cpu) {
+		p = idle_task(cpu);
+		clear_tsk_trace_trace(p);
+	}
+	put_online_cpus();
+}
+
+static void set_ftrace_swapper(void)
+{
+	struct task_struct *p;
+	int cpu;
+
+	get_online_cpus();
+	for_each_online_cpu(cpu) {
+		p = idle_task(cpu);
+		set_tsk_trace_trace(p);
+	}
+	put_online_cpus();
+}
+
+static void clear_ftrace_pid(struct pid *pid)
+{
+	struct task_struct *p;
+
+	do_each_pid_task(pid, PIDTYPE_PID, p) {
+		clear_tsk_trace_trace(p);
+	} while_each_pid_task(pid, PIDTYPE_PID, p);
+	put_pid(pid);
+}
+
+static void set_ftrace_pid(struct pid *pid)
+{
+	struct task_struct *p;
+
+	do_each_pid_task(pid, PIDTYPE_PID, p) {
+		set_tsk_trace_trace(p);
+	} while_each_pid_task(pid, PIDTYPE_PID, p);
+}
+
+static void clear_ftrace_pid_task(struct pid **pid)
+{
+	if (*pid == ftrace_swapper_pid)
+		clear_ftrace_swapper();
+	else
+		clear_ftrace_pid(*pid);
+
+	*pid = NULL;
+}
+
+static void set_ftrace_pid_task(struct pid *pid)
+{
+	if (pid == ftrace_swapper_pid)
+		set_ftrace_swapper();
+	else
+		set_ftrace_pid(pid);
+}
+
+static ssize_t
+ftrace_pid_write(struct file *filp, const char __user *ubuf,
+		   size_t cnt, loff_t *ppos)
+{
+	struct pid *pid;
+	char buf[64];
+	long val;
+	int ret;
+
+	if (cnt >= sizeof(buf))
+		return -EINVAL;
+
+	if (copy_from_user(&buf, ubuf, cnt))
+		return -EFAULT;
+
+	buf[cnt] = 0;
+
+	ret = strict_strtol(buf, 10, &val);
+	if (ret < 0)
+		return ret;
+
+	mutex_lock(&ftrace_start_lock);
+	if (val < 0) {
+		/* disable pid tracing */
+		if (!ftrace_pid_trace)
+			goto out;
+
+		clear_ftrace_pid_task(&ftrace_pid_trace);
+
+	} else {
+		/* swapper task is special */
+		if (!val) {
+			pid = ftrace_swapper_pid;
+			if (pid == ftrace_pid_trace)
+				goto out;
+		} else {
+			pid = find_get_pid(val);
+
+			if (pid == ftrace_pid_trace) {
+				put_pid(pid);
+				goto out;
+			}
+		}
+
+		if (ftrace_pid_trace)
+			clear_ftrace_pid_task(&ftrace_pid_trace);
+
+		if (!pid)
+			goto out;
+
+		ftrace_pid_trace = pid;
+
+		set_ftrace_pid_task(ftrace_pid_trace);
+	}
+
+	/* update the function call */
+	ftrace_update_pid_func();
+	ftrace_startup_enable(0);
+
+ out:
+	mutex_unlock(&ftrace_start_lock);
+
+	return cnt;
+}
+
+static struct file_operations ftrace_pid_fops = {
+	.read = ftrace_pid_read,
+	.write = ftrace_pid_write,
+};
+
+static __init int ftrace_init_debugfs(void)
+{
+	struct dentry *d_tracer;
+	struct dentry *entry;
+
+	d_tracer = tracing_init_dentry();
+	if (!d_tracer)
+		return 0;
+
+	ftrace_init_dyn_debugfs(d_tracer);
+
+	entry = debugfs_create_file("set_ftrace_pid", 0644, d_tracer,
+				    NULL, &ftrace_pid_fops);
+	if (!entry)
+		pr_warning("Could not create debugfs "
+			   "'set_ftrace_pid' entry\n");
+	return 0;
+}
+
+fs_initcall(ftrace_init_debugfs);
+
 /**
  * ftrace_kill - kill ftrace
  *
@@ -1381,10 +1893,11 @@ int register_ftrace_function(struct ftrace_ops *ops)
 		return -1;
 
 	mutex_lock(&ftrace_sysctl_lock);
+
 	ret = __register_ftrace_function(ops);
-	ftrace_startup();
-	mutex_unlock(&ftrace_sysctl_lock);
+	ftrace_startup(0);
 
+	mutex_unlock(&ftrace_sysctl_lock);
 	return ret;
 }
 
@@ -1400,7 +1913,7 @@ int unregister_ftrace_function(struct ftrace_ops *ops)
 
 	mutex_lock(&ftrace_sysctl_lock);
 	ret = __unregister_ftrace_function(ops);
-	ftrace_shutdown();
+	ftrace_shutdown(0);
 	mutex_unlock(&ftrace_sysctl_lock);
 
 	return ret;
@@ -1449,3 +1962,153 @@ ftrace_enable_sysctl(struct ctl_table *table, int write,
 	return ret;
 }
 
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+
+static atomic_t ftrace_graph_active;
+
+int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace)
+{
+	return 0;
+}
+
+/* The callbacks that hook a function */
+trace_func_graph_ret_t ftrace_graph_return =
+			(trace_func_graph_ret_t)ftrace_stub;
+trace_func_graph_ent_t ftrace_graph_entry = ftrace_graph_entry_stub;
+
+/* Try to assign a return stack array on FTRACE_RETSTACK_ALLOC_SIZE tasks. */
+static int alloc_retstack_tasklist(struct ftrace_ret_stack **ret_stack_list)
+{
+	int i;
+	int ret = 0;
+	unsigned long flags;
+	int start = 0, end = FTRACE_RETSTACK_ALLOC_SIZE;
+	struct task_struct *g, *t;
+
+	for (i = 0; i < FTRACE_RETSTACK_ALLOC_SIZE; i++) {
+		ret_stack_list[i] = kmalloc(FTRACE_RETFUNC_DEPTH
+					* sizeof(struct ftrace_ret_stack),
+					GFP_KERNEL);
+		if (!ret_stack_list[i]) {
+			start = 0;
+			end = i;
+			ret = -ENOMEM;
+			goto free;
+		}
+	}
+
+	read_lock_irqsave(&tasklist_lock, flags);
+	do_each_thread(g, t) {
+		if (start == end) {
+			ret = -EAGAIN;
+			goto unlock;
+		}
+
+		if (t->ret_stack == NULL) {
+			t->curr_ret_stack = -1;
+			/* Make sure IRQs see the -1 first: */
+			barrier();
+			t->ret_stack = ret_stack_list[start++];
+			atomic_set(&t->tracing_graph_pause, 0);
+			atomic_set(&t->trace_overrun, 0);
+		}
+	} while_each_thread(g, t);
+
+unlock:
+	read_unlock_irqrestore(&tasklist_lock, flags);
+free:
+	for (i = start; i < end; i++)
+		kfree(ret_stack_list[i]);
+	return ret;
+}
+
+/* Allocate a return stack for each task */
+static int start_graph_tracing(void)
+{
+	struct ftrace_ret_stack **ret_stack_list;
+	int ret;
+
+	ret_stack_list = kmalloc(FTRACE_RETSTACK_ALLOC_SIZE *
+				sizeof(struct ftrace_ret_stack *),
+				GFP_KERNEL);
+
+	if (!ret_stack_list)
+		return -ENOMEM;
+
+	do {
+		ret = alloc_retstack_tasklist(ret_stack_list);
+	} while (ret == -EAGAIN);
+
+	kfree(ret_stack_list);
+	return ret;
+}
+
+int register_ftrace_graph(trace_func_graph_ret_t retfunc,
+			trace_func_graph_ent_t entryfunc)
+{
+	int ret = 0;
+
+	mutex_lock(&ftrace_sysctl_lock);
+
+	atomic_inc(&ftrace_graph_active);
+	ret = start_graph_tracing();
+	if (ret) {
+		atomic_dec(&ftrace_graph_active);
+		goto out;
+	}
+
+	ftrace_graph_return = retfunc;
+	ftrace_graph_entry = entryfunc;
+
+	ftrace_startup(FTRACE_START_FUNC_RET);
+
+out:
+	mutex_unlock(&ftrace_sysctl_lock);
+	return ret;
+}
+
+void unregister_ftrace_graph(void)
+{
+	mutex_lock(&ftrace_sysctl_lock);
+
+	atomic_dec(&ftrace_graph_active);
+	ftrace_graph_return = (trace_func_graph_ret_t)ftrace_stub;
+	ftrace_graph_entry = ftrace_graph_entry_stub;
+	ftrace_shutdown(FTRACE_STOP_FUNC_RET);
+
+	mutex_unlock(&ftrace_sysctl_lock);
+}
+
+/* Allocate a return stack for newly created task */
+void ftrace_graph_init_task(struct task_struct *t)
+{
+	if (atomic_read(&ftrace_graph_active)) {
+		t->ret_stack = kmalloc(FTRACE_RETFUNC_DEPTH
+				* sizeof(struct ftrace_ret_stack),
+				GFP_KERNEL);
+		if (!t->ret_stack)
+			return;
+		t->curr_ret_stack = -1;
+		atomic_set(&t->tracing_graph_pause, 0);
+		atomic_set(&t->trace_overrun, 0);
+	} else
+		t->ret_stack = NULL;
+}
+
+void ftrace_graph_exit_task(struct task_struct *t)
+{
+	struct ftrace_ret_stack	*ret_stack = t->ret_stack;
+
+	t->ret_stack = NULL;
+	/* NULL must become visible to IRQs before we free it: */
+	barrier();
+
+	kfree(ret_stack);
+}
+
+void ftrace_graph_stop(void)
+{
+	ftrace_stop();
+}
+#endif
+
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index 668bbb5..76f34c0 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -18,8 +18,46 @@
 
 #include "trace.h"
 
-/* Global flag to disable all recording to ring buffers */
-static int ring_buffers_off __read_mostly;
+/*
+ * A fast way to enable or disable all ring buffers is to
+ * call tracing_on or tracing_off. Turning off the ring buffers
+ * prevents all ring buffers from being recorded to.
+ * Turning this switch on, makes it OK to write to the
+ * ring buffer, if the ring buffer is enabled itself.
+ *
+ * There's three layers that must be on in order to write
+ * to the ring buffer.
+ *
+ * 1) This global flag must be set.
+ * 2) The ring buffer must be enabled for recording.
+ * 3) The per cpu buffer must be enabled for recording.
+ *
+ * In case of an anomaly, this global flag has a bit set that
+ * will permantly disable all ring buffers.
+ */
+
+/*
+ * Global flag to disable all recording to ring buffers
+ *  This has two bits: ON, DISABLED
+ *
+ *  ON   DISABLED
+ * ---- ----------
+ *   0      0        : ring buffers are off
+ *   1      0        : ring buffers are on
+ *   X      1        : ring buffers are permanently disabled
+ */
+
+enum {
+	RB_BUFFERS_ON_BIT	= 0,
+	RB_BUFFERS_DISABLED_BIT	= 1,
+};
+
+enum {
+	RB_BUFFERS_ON		= 1 << RB_BUFFERS_ON_BIT,
+	RB_BUFFERS_DISABLED	= 1 << RB_BUFFERS_DISABLED_BIT,
+};
+
+static long ring_buffer_flags __read_mostly = RB_BUFFERS_ON;
 
 /**
  * tracing_on - enable all tracing buffers
@@ -29,7 +67,7 @@ static int ring_buffers_off __read_mostly;
  */
 void tracing_on(void)
 {
-	ring_buffers_off = 0;
+	set_bit(RB_BUFFERS_ON_BIT, &ring_buffer_flags);
 }
 
 /**
@@ -42,9 +80,22 @@ void tracing_on(void)
  */
 void tracing_off(void)
 {
-	ring_buffers_off = 1;
+	clear_bit(RB_BUFFERS_ON_BIT, &ring_buffer_flags);
 }
 
+/**
+ * tracing_off_permanent - permanently disable ring buffers
+ *
+ * This function, once called, will disable all ring buffers
+ * permanenty.
+ */
+void tracing_off_permanent(void)
+{
+	set_bit(RB_BUFFERS_DISABLED_BIT, &ring_buffer_flags);
+}
+
+#include "trace.h"
+
 /* Up this if you want to test the TIME_EXTENTS and normalization */
 #define DEBUG_SHIFT 0
 
@@ -56,7 +107,7 @@ u64 ring_buffer_time_stamp(int cpu)
 	preempt_disable_notrace();
 	/* shift to debug/test normalization and TIME_EXTENTS */
 	time = sched_clock() << DEBUG_SHIFT;
-	preempt_enable_notrace();
+	preempt_enable_no_resched_notrace();
 
 	return time;
 }
@@ -144,20 +195,24 @@ void *ring_buffer_event_data(struct ring_buffer_event *event)
 #define TS_MASK		((1ULL << TS_SHIFT) - 1)
 #define TS_DELTA_TEST	(~TS_MASK)
 
-/*
- * This hack stolen from mm/slob.c.
- * We can store per page timing information in the page frame of the page.
- * Thanks to Peter Zijlstra for suggesting this idea.
- */
-struct buffer_page {
+struct buffer_data_page {
 	u64		 time_stamp;	/* page time stamp */
-	local_t		 write;		/* index for next write */
 	local_t		 commit;	/* write commited index */
+	unsigned char	 data[];	/* data of buffer page */
+};
+
+struct buffer_page {
+	local_t		 write;		/* index for next write */
 	unsigned	 read;		/* index for next read */
 	struct list_head list;		/* list of free pages */
-	void *page;			/* Actual data page */
+	struct buffer_data_page *page;	/* Actual data page */
 };
 
+static void rb_init_page(struct buffer_data_page *bpage)
+{
+	local_set(&bpage->commit, 0);
+}
+
 /*
  * Also stolen from mm/slob.c. Thanks to Mathieu Desnoyers for pointing
  * this issue out.
@@ -179,7 +234,7 @@ static inline int test_time_stamp(u64 delta)
 	return 0;
 }
 
-#define BUF_PAGE_SIZE PAGE_SIZE
+#define BUF_PAGE_SIZE (PAGE_SIZE - sizeof(struct buffer_data_page))
 
 /*
  * head_page == tail_page && head == tail then buffer is empty.
@@ -187,7 +242,8 @@ static inline int test_time_stamp(u64 delta)
 struct ring_buffer_per_cpu {
 	int				cpu;
 	struct ring_buffer		*buffer;
-	spinlock_t			lock;
+	spinlock_t			reader_lock; /* serialize readers */
+	raw_spinlock_t			lock;
 	struct lock_class_key		lock_key;
 	struct list_head		pages;
 	struct buffer_page		*head_page;	/* read from head */
@@ -202,7 +258,6 @@ struct ring_buffer_per_cpu {
 };
 
 struct ring_buffer {
-	unsigned long			size;
 	unsigned			pages;
 	unsigned			flags;
 	int				cpus;
@@ -221,32 +276,16 @@ struct ring_buffer_iter {
 	u64				read_stamp;
 };
 
+/* buffer may be either ring_buffer or ring_buffer_per_cpu */
 #define RB_WARN_ON(buffer, cond)				\
-	do {							\
-		if (unlikely(cond)) {				\
-			atomic_inc(&buffer->record_disabled);	\
-			WARN_ON(1);				\
-		}						\
-	} while (0)
-
-#define RB_WARN_ON_RET(buffer, cond)				\
-	do {							\
-		if (unlikely(cond)) {				\
-			atomic_inc(&buffer->record_disabled);	\
-			WARN_ON(1);				\
-			return -1;				\
-		}						\
-	} while (0)
-
-#define RB_WARN_ON_ONCE(buffer, cond)				\
-	do {							\
-		static int once;				\
-		if (unlikely(cond) && !once) {			\
-			once++;					\
+	({							\
+		int _____ret = unlikely(cond);			\
+		if (_____ret) {					\
 			atomic_inc(&buffer->record_disabled);	\
 			WARN_ON(1);				\
 		}						\
-	} while (0)
+		_____ret;					\
+	})
 
 /**
  * check_pages - integrity check of buffer pages
@@ -258,16 +297,20 @@ struct ring_buffer_iter {
 static int rb_check_pages(struct ring_buffer_per_cpu *cpu_buffer)
 {
 	struct list_head *head = &cpu_buffer->pages;
-	struct buffer_page *page, *tmp;
+	struct buffer_page *bpage, *tmp;
 
-	RB_WARN_ON_RET(cpu_buffer, head->next->prev != head);
-	RB_WARN_ON_RET(cpu_buffer, head->prev->next != head);
+	if (RB_WARN_ON(cpu_buffer, head->next->prev != head))
+		return -1;
+	if (RB_WARN_ON(cpu_buffer, head->prev->next != head))
+		return -1;
 
-	list_for_each_entry_safe(page, tmp, head, list) {
-		RB_WARN_ON_RET(cpu_buffer,
-			       page->list.next->prev != &page->list);
-		RB_WARN_ON_RET(cpu_buffer,
-			       page->list.prev->next != &page->list);
+	list_for_each_entry_safe(bpage, tmp, head, list) {
+		if (RB_WARN_ON(cpu_buffer,
+			       bpage->list.next->prev != &bpage->list))
+			return -1;
+		if (RB_WARN_ON(cpu_buffer,
+			       bpage->list.prev->next != &bpage->list))
+			return -1;
 	}
 
 	return 0;
@@ -277,22 +320,23 @@ static int rb_allocate_pages(struct ring_buffer_per_cpu *cpu_buffer,
 			     unsigned nr_pages)
 {
 	struct list_head *head = &cpu_buffer->pages;
-	struct buffer_page *page, *tmp;
+	struct buffer_page *bpage, *tmp;
 	unsigned long addr;
 	LIST_HEAD(pages);
 	unsigned i;
 
 	for (i = 0; i < nr_pages; i++) {
-		page = kzalloc_node(ALIGN(sizeof(*page), cache_line_size()),
+		bpage = kzalloc_node(ALIGN(sizeof(*bpage), cache_line_size()),
 				    GFP_KERNEL, cpu_to_node(cpu_buffer->cpu));
-		if (!page)
+		if (!bpage)
 			goto free_pages;
-		list_add(&page->list, &pages);
+		list_add(&bpage->list, &pages);
 
 		addr = __get_free_page(GFP_KERNEL);
 		if (!addr)
 			goto free_pages;
-		page->page = (void *)addr;
+		bpage->page = (void *)addr;
+		rb_init_page(bpage->page);
 	}
 
 	list_splice(&pages, head);
@@ -302,9 +346,9 @@ static int rb_allocate_pages(struct ring_buffer_per_cpu *cpu_buffer,
 	return 0;
 
  free_pages:
-	list_for_each_entry_safe(page, tmp, &pages, list) {
-		list_del_init(&page->list);
-		free_buffer_page(page);
+	list_for_each_entry_safe(bpage, tmp, &pages, list) {
+		list_del_init(&bpage->list);
+		free_buffer_page(bpage);
 	}
 	return -ENOMEM;
 }
@@ -313,7 +357,7 @@ static struct ring_buffer_per_cpu *
 rb_allocate_cpu_buffer(struct ring_buffer *buffer, int cpu)
 {
 	struct ring_buffer_per_cpu *cpu_buffer;
-	struct buffer_page *page;
+	struct buffer_page *bpage;
 	unsigned long addr;
 	int ret;
 
@@ -324,19 +368,21 @@ rb_allocate_cpu_buffer(struct ring_buffer *buffer, int cpu)
 
 	cpu_buffer->cpu = cpu;
 	cpu_buffer->buffer = buffer;
-	spin_lock_init(&cpu_buffer->lock);
+	spin_lock_init(&cpu_buffer->reader_lock);
+	cpu_buffer->lock = (raw_spinlock_t)__RAW_SPIN_LOCK_UNLOCKED;
 	INIT_LIST_HEAD(&cpu_buffer->pages);
 
-	page = kzalloc_node(ALIGN(sizeof(*page), cache_line_size()),
+	bpage = kzalloc_node(ALIGN(sizeof(*bpage), cache_line_size()),
 			    GFP_KERNEL, cpu_to_node(cpu));
-	if (!page)
+	if (!bpage)
 		goto fail_free_buffer;
 
-	cpu_buffer->reader_page = page;
+	cpu_buffer->reader_page = bpage;
 	addr = __get_free_page(GFP_KERNEL);
 	if (!addr)
 		goto fail_free_reader;
-	page->page = (void *)addr;
+	bpage->page = (void *)addr;
+	rb_init_page(bpage->page);
 
 	INIT_LIST_HEAD(&cpu_buffer->reader_page->list);
 
@@ -361,14 +407,14 @@ rb_allocate_cpu_buffer(struct ring_buffer *buffer, int cpu)
 static void rb_free_cpu_buffer(struct ring_buffer_per_cpu *cpu_buffer)
 {
 	struct list_head *head = &cpu_buffer->pages;
-	struct buffer_page *page, *tmp;
+	struct buffer_page *bpage, *tmp;
 
 	list_del_init(&cpu_buffer->reader_page->list);
 	free_buffer_page(cpu_buffer->reader_page);
 
-	list_for_each_entry_safe(page, tmp, head, list) {
-		list_del_init(&page->list);
-		free_buffer_page(page);
+	list_for_each_entry_safe(bpage, tmp, head, list) {
+		list_del_init(&bpage->list);
+		free_buffer_page(bpage);
 	}
 	kfree(cpu_buffer);
 }
@@ -465,7 +511,7 @@ static void rb_reset_cpu(struct ring_buffer_per_cpu *cpu_buffer);
 static void
 rb_remove_pages(struct ring_buffer_per_cpu *cpu_buffer, unsigned nr_pages)
 {
-	struct buffer_page *page;
+	struct buffer_page *bpage;
 	struct list_head *p;
 	unsigned i;
 
@@ -473,13 +519,15 @@ rb_remove_pages(struct ring_buffer_per_cpu *cpu_buffer, unsigned nr_pages)
 	synchronize_sched();
 
 	for (i = 0; i < nr_pages; i++) {
-		BUG_ON(list_empty(&cpu_buffer->pages));
+		if (RB_WARN_ON(cpu_buffer, list_empty(&cpu_buffer->pages)))
+			return;
 		p = cpu_buffer->pages.next;
-		page = list_entry(p, struct buffer_page, list);
-		list_del_init(&page->list);
-		free_buffer_page(page);
+		bpage = list_entry(p, struct buffer_page, list);
+		list_del_init(&bpage->list);
+		free_buffer_page(bpage);
 	}
-	BUG_ON(list_empty(&cpu_buffer->pages));
+	if (RB_WARN_ON(cpu_buffer, list_empty(&cpu_buffer->pages)))
+		return;
 
 	rb_reset_cpu(cpu_buffer);
 
@@ -493,7 +541,7 @@ static void
 rb_insert_pages(struct ring_buffer_per_cpu *cpu_buffer,
 		struct list_head *pages, unsigned nr_pages)
 {
-	struct buffer_page *page;
+	struct buffer_page *bpage;
 	struct list_head *p;
 	unsigned i;
 
@@ -501,11 +549,12 @@ rb_insert_pages(struct ring_buffer_per_cpu *cpu_buffer,
 	synchronize_sched();
 
 	for (i = 0; i < nr_pages; i++) {
-		BUG_ON(list_empty(pages));
+		if (RB_WARN_ON(cpu_buffer, list_empty(pages)))
+			return;
 		p = pages->next;
-		page = list_entry(p, struct buffer_page, list);
-		list_del_init(&page->list);
-		list_add_tail(&page->list, &cpu_buffer->pages);
+		bpage = list_entry(p, struct buffer_page, list);
+		list_del_init(&bpage->list);
+		list_add_tail(&bpage->list, &cpu_buffer->pages);
 	}
 	rb_reset_cpu(cpu_buffer);
 
@@ -532,7 +581,7 @@ int ring_buffer_resize(struct ring_buffer *buffer, unsigned long size)
 {
 	struct ring_buffer_per_cpu *cpu_buffer;
 	unsigned nr_pages, rm_pages, new_pages;
-	struct buffer_page *page, *tmp;
+	struct buffer_page *bpage, *tmp;
 	unsigned long buffer_size;
 	unsigned long addr;
 	LIST_HEAD(pages);
@@ -562,7 +611,10 @@ int ring_buffer_resize(struct ring_buffer *buffer, unsigned long size)
 	if (size < buffer_size) {
 
 		/* easy case, just free pages */
-		BUG_ON(nr_pages >= buffer->pages);
+		if (RB_WARN_ON(buffer, nr_pages >= buffer->pages)) {
+			mutex_unlock(&buffer->mutex);
+			return -1;
+		}
 
 		rm_pages = buffer->pages - nr_pages;
 
@@ -581,21 +633,26 @@ int ring_buffer_resize(struct ring_buffer *buffer, unsigned long size)
 	 * add these pages to the cpu_buffers. Otherwise we just free
 	 * them all and return -ENOMEM;
 	 */
-	BUG_ON(nr_pages <= buffer->pages);
+	if (RB_WARN_ON(buffer, nr_pages <= buffer->pages)) {
+		mutex_unlock(&buffer->mutex);
+		return -1;
+	}
+
 	new_pages = nr_pages - buffer->pages;
 
 	for_each_buffer_cpu(buffer, cpu) {
 		for (i = 0; i < new_pages; i++) {
-			page = kzalloc_node(ALIGN(sizeof(*page),
+			bpage = kzalloc_node(ALIGN(sizeof(*bpage),
 						  cache_line_size()),
 					    GFP_KERNEL, cpu_to_node(cpu));
-			if (!page)
+			if (!bpage)
 				goto free_pages;
-			list_add(&page->list, &pages);
+			list_add(&bpage->list, &pages);
 			addr = __get_free_page(GFP_KERNEL);
 			if (!addr)
 				goto free_pages;
-			page->page = (void *)addr;
+			bpage->page = (void *)addr;
+			rb_init_page(bpage->page);
 		}
 	}
 
@@ -604,7 +661,10 @@ int ring_buffer_resize(struct ring_buffer *buffer, unsigned long size)
 		rb_insert_pages(cpu_buffer, &pages, new_pages);
 	}
 
-	BUG_ON(!list_empty(&pages));
+	if (RB_WARN_ON(buffer, !list_empty(&pages))) {
+		mutex_unlock(&buffer->mutex);
+		return -1;
+	}
 
  out:
 	buffer->pages = nr_pages;
@@ -613,9 +673,9 @@ int ring_buffer_resize(struct ring_buffer *buffer, unsigned long size)
 	return size;
 
  free_pages:
-	list_for_each_entry_safe(page, tmp, &pages, list) {
-		list_del_init(&page->list);
-		free_buffer_page(page);
+	list_for_each_entry_safe(bpage, tmp, &pages, list) {
+		list_del_init(&bpage->list);
+		free_buffer_page(bpage);
 	}
 	mutex_unlock(&buffer->mutex);
 	return -ENOMEM;
@@ -626,9 +686,15 @@ static inline int rb_null_event(struct ring_buffer_event *event)
 	return event->type == RINGBUF_TYPE_PADDING;
 }
 
-static inline void *__rb_page_index(struct buffer_page *page, unsigned index)
+static inline void *
+__rb_data_page_index(struct buffer_data_page *bpage, unsigned index)
+{
+	return bpage->data + index;
+}
+
+static inline void *__rb_page_index(struct buffer_page *bpage, unsigned index)
 {
-	return page->page + index;
+	return bpage->page->data + index;
 }
 
 static inline struct ring_buffer_event *
@@ -658,7 +724,7 @@ static inline unsigned rb_page_write(struct buffer_page *bpage)
 
 static inline unsigned rb_page_commit(struct buffer_page *bpage)
 {
-	return local_read(&bpage->commit);
+	return local_read(&bpage->page->commit);
 }
 
 /* Size is determined by what has been commited */
@@ -693,7 +759,8 @@ static void rb_update_overflow(struct ring_buffer_per_cpu *cpu_buffer)
 	     head += rb_event_length(event)) {
 
 		event = __rb_page_index(cpu_buffer->head_page, head);
-		BUG_ON(rb_null_event(event));
+		if (RB_WARN_ON(cpu_buffer, rb_null_event(event)))
+			return;
 		/* Only count data entries */
 		if (event->type != RINGBUF_TYPE_DATA)
 			continue;
@@ -703,14 +770,14 @@ static void rb_update_overflow(struct ring_buffer_per_cpu *cpu_buffer)
 }
 
 static inline void rb_inc_page(struct ring_buffer_per_cpu *cpu_buffer,
-			       struct buffer_page **page)
+			       struct buffer_page **bpage)
 {
-	struct list_head *p = (*page)->list.next;
+	struct list_head *p = (*bpage)->list.next;
 
 	if (p == &cpu_buffer->pages)
 		p = p->next;
 
-	*page = list_entry(p, struct buffer_page, list);
+	*bpage = list_entry(p, struct buffer_page, list);
 }
 
 static inline unsigned
@@ -746,16 +813,18 @@ rb_set_commit_event(struct ring_buffer_per_cpu *cpu_buffer,
 	addr &= PAGE_MASK;
 
 	while (cpu_buffer->commit_page->page != (void *)addr) {
-		RB_WARN_ON(cpu_buffer,
-			   cpu_buffer->commit_page == cpu_buffer->tail_page);
-		cpu_buffer->commit_page->commit =
+		if (RB_WARN_ON(cpu_buffer,
+			  cpu_buffer->commit_page == cpu_buffer->tail_page))
+			return;
+		cpu_buffer->commit_page->page->commit =
 			cpu_buffer->commit_page->write;
 		rb_inc_page(cpu_buffer, &cpu_buffer->commit_page);
-		cpu_buffer->write_stamp = cpu_buffer->commit_page->time_stamp;
+		cpu_buffer->write_stamp =
+			cpu_buffer->commit_page->page->time_stamp;
 	}
 
 	/* Now set the commit to the event's index */
-	local_set(&cpu_buffer->commit_page->commit, index);
+	local_set(&cpu_buffer->commit_page->page->commit, index);
 }
 
 static inline void
@@ -769,25 +838,38 @@ rb_set_commit_to_write(struct ring_buffer_per_cpu *cpu_buffer)
 	 * back to us). This allows us to do a simple loop to
 	 * assign the commit to the tail.
 	 */
+ again:
 	while (cpu_buffer->commit_page != cpu_buffer->tail_page) {
-		cpu_buffer->commit_page->commit =
+		cpu_buffer->commit_page->page->commit =
 			cpu_buffer->commit_page->write;
 		rb_inc_page(cpu_buffer, &cpu_buffer->commit_page);
-		cpu_buffer->write_stamp = cpu_buffer->commit_page->time_stamp;
+		cpu_buffer->write_stamp =
+			cpu_buffer->commit_page->page->time_stamp;
 		/* add barrier to keep gcc from optimizing too much */
 		barrier();
 	}
 	while (rb_commit_index(cpu_buffer) !=
 	       rb_page_write(cpu_buffer->commit_page)) {
-		cpu_buffer->commit_page->commit =
+		cpu_buffer->commit_page->page->commit =
 			cpu_buffer->commit_page->write;
 		barrier();
 	}
+
+	/* again, keep gcc from optimizing */
+	barrier();
+
+	/*
+	 * If an interrupt came in just after the first while loop
+	 * and pushed the tail page forward, we will be left with
+	 * a dangling commit that will never go forward.
+	 */
+	if (unlikely(cpu_buffer->commit_page != cpu_buffer->tail_page))
+		goto again;
 }
 
 static void rb_reset_reader_page(struct ring_buffer_per_cpu *cpu_buffer)
 {
-	cpu_buffer->read_stamp = cpu_buffer->reader_page->time_stamp;
+	cpu_buffer->read_stamp = cpu_buffer->reader_page->page->time_stamp;
 	cpu_buffer->reader_page->read = 0;
 }
 
@@ -806,7 +888,7 @@ static inline void rb_inc_iter(struct ring_buffer_iter *iter)
 	else
 		rb_inc_page(cpu_buffer, &iter->head_page);
 
-	iter->read_stamp = iter->head_page->time_stamp;
+	iter->read_stamp = iter->head_page->page->time_stamp;
 	iter->head = 0;
 }
 
@@ -880,12 +962,15 @@ static struct ring_buffer_event *
 __rb_reserve_next(struct ring_buffer_per_cpu *cpu_buffer,
 		  unsigned type, unsigned long length, u64 *ts)
 {
-	struct buffer_page *tail_page, *head_page, *reader_page;
+	struct buffer_page *tail_page, *head_page, *reader_page, *commit_page;
 	unsigned long tail, write;
 	struct ring_buffer *buffer = cpu_buffer->buffer;
 	struct ring_buffer_event *event;
 	unsigned long flags;
 
+	commit_page = cpu_buffer->commit_page;
+	/* we just need to protect against interrupts */
+	barrier();
 	tail_page = cpu_buffer->tail_page;
 	write = local_add_return(length, &tail_page->write);
 	tail = write - length;
@@ -894,7 +979,8 @@ __rb_reserve_next(struct ring_buffer_per_cpu *cpu_buffer,
 	if (write > BUF_PAGE_SIZE) {
 		struct buffer_page *next_page = tail_page;
 
-		spin_lock_irqsave(&cpu_buffer->lock, flags);
+		local_irq_save(flags);
+		__raw_spin_lock(&cpu_buffer->lock);
 
 		rb_inc_page(cpu_buffer, &next_page);
 
@@ -902,14 +988,15 @@ __rb_reserve_next(struct ring_buffer_per_cpu *cpu_buffer,
 		reader_page = cpu_buffer->reader_page;
 
 		/* we grabbed the lock before incrementing */
-		RB_WARN_ON(cpu_buffer, next_page == reader_page);
+		if (RB_WARN_ON(cpu_buffer, next_page == reader_page))
+			goto out_unlock;
 
 		/*
 		 * If for some reason, we had an interrupt storm that made
 		 * it all the way around the buffer, bail, and warn
 		 * about it.
 		 */
-		if (unlikely(next_page == cpu_buffer->commit_page)) {
+		if (unlikely(next_page == commit_page)) {
 			WARN_ON_ONCE(1);
 			goto out_unlock;
 		}
@@ -940,12 +1027,12 @@ __rb_reserve_next(struct ring_buffer_per_cpu *cpu_buffer,
 		 */
 		if (tail_page == cpu_buffer->tail_page) {
 			local_set(&next_page->write, 0);
-			local_set(&next_page->commit, 0);
+			local_set(&next_page->page->commit, 0);
 			cpu_buffer->tail_page = next_page;
 
 			/* reread the time stamp */
 			*ts = ring_buffer_time_stamp(cpu_buffer->cpu);
-			cpu_buffer->tail_page->time_stamp = *ts;
+			cpu_buffer->tail_page->page->time_stamp = *ts;
 		}
 
 		/*
@@ -970,7 +1057,8 @@ __rb_reserve_next(struct ring_buffer_per_cpu *cpu_buffer,
 			rb_set_commit_to_write(cpu_buffer);
 		}
 
-		spin_unlock_irqrestore(&cpu_buffer->lock, flags);
+		__raw_spin_unlock(&cpu_buffer->lock);
+		local_irq_restore(flags);
 
 		/* fail and let the caller try again */
 		return ERR_PTR(-EAGAIN);
@@ -978,7 +1066,8 @@ __rb_reserve_next(struct ring_buffer_per_cpu *cpu_buffer,
 
 	/* We reserved something on the buffer */
 
-	BUG_ON(write > BUF_PAGE_SIZE);
+	if (RB_WARN_ON(cpu_buffer, write > BUF_PAGE_SIZE))
+		return NULL;
 
 	event = __rb_page_index(tail_page, tail);
 	rb_update_event(event, type, length);
@@ -988,12 +1077,13 @@ __rb_reserve_next(struct ring_buffer_per_cpu *cpu_buffer,
 	 * this page's time stamp.
 	 */
 	if (!tail && rb_is_commit(cpu_buffer, event))
-		cpu_buffer->commit_page->time_stamp = *ts;
+		cpu_buffer->commit_page->page->time_stamp = *ts;
 
 	return event;
 
  out_unlock:
-	spin_unlock_irqrestore(&cpu_buffer->lock, flags);
+	__raw_spin_unlock(&cpu_buffer->lock);
+	local_irq_restore(flags);
 	return NULL;
 }
 
@@ -1038,7 +1128,7 @@ rb_add_time_stamp(struct ring_buffer_per_cpu *cpu_buffer,
 			event->time_delta = *delta & TS_MASK;
 			event->array[0] = *delta >> TS_SHIFT;
 		} else {
-			cpu_buffer->commit_page->time_stamp = *ts;
+			cpu_buffer->commit_page->page->time_stamp = *ts;
 			event->time_delta = 0;
 			event->array[0] = 0;
 		}
@@ -1076,10 +1166,8 @@ rb_reserve_next_event(struct ring_buffer_per_cpu *cpu_buffer,
 	 * storm or we have something buggy.
 	 * Bail!
 	 */
-	if (unlikely(++nr_loops > 1000)) {
-		RB_WARN_ON(cpu_buffer, 1);
+	if (RB_WARN_ON(cpu_buffer, ++nr_loops > 1000))
 		return NULL;
-	}
 
 	ts = ring_buffer_time_stamp(cpu_buffer->cpu);
 
@@ -1175,15 +1263,14 @@ ring_buffer_lock_reserve(struct ring_buffer *buffer,
 	struct ring_buffer_event *event;
 	int cpu, resched;
 
-	if (ring_buffers_off)
+	if (ring_buffer_flags != RB_BUFFERS_ON)
 		return NULL;
 
 	if (atomic_read(&buffer->record_disabled))
 		return NULL;
 
 	/* If we are tracing schedule, we don't want to recurse */
-	resched = need_resched();
-	preempt_disable_notrace();
+	resched = ftrace_preempt_disable();
 
 	cpu = raw_smp_processor_id();
 
@@ -1214,10 +1301,7 @@ ring_buffer_lock_reserve(struct ring_buffer *buffer,
 	return event;
 
  out:
-	if (resched)
-		preempt_enable_no_resched_notrace();
-	else
-		preempt_enable_notrace();
+	ftrace_preempt_enable(resched);
 	return NULL;
 }
 
@@ -1259,12 +1343,9 @@ int ring_buffer_unlock_commit(struct ring_buffer *buffer,
 	/*
 	 * Only the last preempt count needs to restore preemption.
 	 */
-	if (preempt_count() == 1) {
-		if (per_cpu(rb_need_resched, cpu))
-			preempt_enable_no_resched_notrace();
-		else
-			preempt_enable_notrace();
-	} else
+	if (preempt_count() == 1)
+		ftrace_preempt_enable(per_cpu(rb_need_resched, cpu));
+	else
 		preempt_enable_no_resched_notrace();
 
 	return 0;
@@ -1294,14 +1375,13 @@ int ring_buffer_write(struct ring_buffer *buffer,
 	int ret = -EBUSY;
 	int cpu, resched;
 
-	if (ring_buffers_off)
+	if (ring_buffer_flags != RB_BUFFERS_ON)
 		return -EBUSY;
 
 	if (atomic_read(&buffer->record_disabled))
 		return -EBUSY;
 
-	resched = need_resched();
-	preempt_disable_notrace();
+	resched = ftrace_preempt_disable();
 
 	cpu = raw_smp_processor_id();
 
@@ -1327,10 +1407,7 @@ int ring_buffer_write(struct ring_buffer *buffer,
 
 	ret = 0;
  out:
-	if (resched)
-		preempt_enable_no_resched_notrace();
-	else
-		preempt_enable_notrace();
+	ftrace_preempt_enable(resched);
 
 	return ret;
 }
@@ -1489,14 +1566,7 @@ unsigned long ring_buffer_overruns(struct ring_buffer *buffer)
 	return overruns;
 }
 
-/**
- * ring_buffer_iter_reset - reset an iterator
- * @iter: The iterator to reset
- *
- * Resets the iterator, so that it will start from the beginning
- * again.
- */
-void ring_buffer_iter_reset(struct ring_buffer_iter *iter)
+static void rb_iter_reset(struct ring_buffer_iter *iter)
 {
 	struct ring_buffer_per_cpu *cpu_buffer = iter->cpu_buffer;
 
@@ -1511,7 +1581,24 @@ void ring_buffer_iter_reset(struct ring_buffer_iter *iter)
 	if (iter->head)
 		iter->read_stamp = cpu_buffer->read_stamp;
 	else
-		iter->read_stamp = iter->head_page->time_stamp;
+		iter->read_stamp = iter->head_page->page->time_stamp;
+}
+
+/**
+ * ring_buffer_iter_reset - reset an iterator
+ * @iter: The iterator to reset
+ *
+ * Resets the iterator, so that it will start from the beginning
+ * again.
+ */
+void ring_buffer_iter_reset(struct ring_buffer_iter *iter)
+{
+	struct ring_buffer_per_cpu *cpu_buffer = iter->cpu_buffer;
+	unsigned long flags;
+
+	spin_lock_irqsave(&cpu_buffer->reader_lock, flags);
+	rb_iter_reset(iter);
+	spin_unlock_irqrestore(&cpu_buffer->reader_lock, flags);
 }
 
 /**
@@ -1597,7 +1684,8 @@ rb_get_reader_page(struct ring_buffer_per_cpu *cpu_buffer)
 	unsigned long flags;
 	int nr_loops = 0;
 
-	spin_lock_irqsave(&cpu_buffer->lock, flags);
+	local_irq_save(flags);
+	__raw_spin_lock(&cpu_buffer->lock);
 
  again:
 	/*
@@ -1606,8 +1694,7 @@ rb_get_reader_page(struct ring_buffer_per_cpu *cpu_buffer)
 	 * a case where we will loop three times. There should be no
 	 * reason to loop four times (that I know of).
 	 */
-	if (unlikely(++nr_loops > 3)) {
-		RB_WARN_ON(cpu_buffer, 1);
+	if (RB_WARN_ON(cpu_buffer, ++nr_loops > 3)) {
 		reader = NULL;
 		goto out;
 	}
@@ -1619,8 +1706,9 @@ rb_get_reader_page(struct ring_buffer_per_cpu *cpu_buffer)
 		goto out;
 
 	/* Never should we have an index greater than the size */
-	RB_WARN_ON(cpu_buffer,
-		   cpu_buffer->reader_page->read > rb_page_size(reader));
+	if (RB_WARN_ON(cpu_buffer,
+		       cpu_buffer->reader_page->read > rb_page_size(reader)))
+		goto out;
 
 	/* check if we caught up to the tail */
 	reader = NULL;
@@ -1637,7 +1725,7 @@ rb_get_reader_page(struct ring_buffer_per_cpu *cpu_buffer)
 	cpu_buffer->reader_page->list.prev = reader->list.prev;
 
 	local_set(&cpu_buffer->reader_page->write, 0);
-	local_set(&cpu_buffer->reader_page->commit, 0);
+	local_set(&cpu_buffer->reader_page->page->commit, 0);
 
 	/* Make the reader page now replace the head */
 	reader->list.prev->next = &cpu_buffer->reader_page->list;
@@ -1659,7 +1747,8 @@ rb_get_reader_page(struct ring_buffer_per_cpu *cpu_buffer)
 	goto again;
 
  out:
-	spin_unlock_irqrestore(&cpu_buffer->lock, flags);
+	__raw_spin_unlock(&cpu_buffer->lock);
+	local_irq_restore(flags);
 
 	return reader;
 }
@@ -1673,7 +1762,8 @@ static void rb_advance_reader(struct ring_buffer_per_cpu *cpu_buffer)
 	reader = rb_get_reader_page(cpu_buffer);
 
 	/* This function should not be called when buffer is empty */
-	BUG_ON(!reader);
+	if (RB_WARN_ON(cpu_buffer, !reader))
+		return;
 
 	event = rb_reader_event(cpu_buffer);
 
@@ -1700,7 +1790,9 @@ static void rb_advance_iter(struct ring_buffer_iter *iter)
 	 * Check if we are at the end of the buffer.
 	 */
 	if (iter->head >= rb_page_size(iter->head_page)) {
-		BUG_ON(iter->head_page == cpu_buffer->commit_page);
+		if (RB_WARN_ON(buffer,
+			       iter->head_page == cpu_buffer->commit_page))
+			return;
 		rb_inc_iter(iter);
 		return;
 	}
@@ -1713,8 +1805,10 @@ static void rb_advance_iter(struct ring_buffer_iter *iter)
 	 * This should not be called to advance the header if we are
 	 * at the tail of the buffer.
 	 */
-	BUG_ON((iter->head_page == cpu_buffer->commit_page) &&
-	       (iter->head + length > rb_commit_index(cpu_buffer)));
+	if (RB_WARN_ON(cpu_buffer,
+		       (iter->head_page == cpu_buffer->commit_page) &&
+		       (iter->head + length > rb_commit_index(cpu_buffer))))
+		return;
 
 	rb_update_iter_read_stamp(iter, event);
 
@@ -1726,17 +1820,8 @@ static void rb_advance_iter(struct ring_buffer_iter *iter)
 		rb_advance_iter(iter);
 }
 
-/**
- * ring_buffer_peek - peek at the next event to be read
- * @buffer: The ring buffer to read
- * @cpu: The cpu to peak at
- * @ts: The timestamp counter of this event.
- *
- * This will return the event that will be read next, but does
- * not consume the data.
- */
-struct ring_buffer_event *
-ring_buffer_peek(struct ring_buffer *buffer, int cpu, u64 *ts)
+static struct ring_buffer_event *
+rb_buffer_peek(struct ring_buffer *buffer, int cpu, u64 *ts)
 {
 	struct ring_buffer_per_cpu *cpu_buffer;
 	struct ring_buffer_event *event;
@@ -1757,10 +1842,8 @@ ring_buffer_peek(struct ring_buffer *buffer, int cpu, u64 *ts)
 	 * can have.  Nesting 10 deep of interrupts is clearly
 	 * an anomaly.
 	 */
-	if (unlikely(++nr_loops > 10)) {
-		RB_WARN_ON(cpu_buffer, 1);
+	if (RB_WARN_ON(cpu_buffer, ++nr_loops > 10))
 		return NULL;
-	}
 
 	reader = rb_get_reader_page(cpu_buffer);
 	if (!reader)
@@ -1798,16 +1881,8 @@ ring_buffer_peek(struct ring_buffer *buffer, int cpu, u64 *ts)
 	return NULL;
 }
 
-/**
- * ring_buffer_iter_peek - peek at the next event to be read
- * @iter: The ring buffer iterator
- * @ts: The timestamp counter of this event.
- *
- * This will return the event that will be read next, but does
- * not increment the iterator.
- */
-struct ring_buffer_event *
-ring_buffer_iter_peek(struct ring_buffer_iter *iter, u64 *ts)
+static struct ring_buffer_event *
+rb_iter_peek(struct ring_buffer_iter *iter, u64 *ts)
 {
 	struct ring_buffer *buffer;
 	struct ring_buffer_per_cpu *cpu_buffer;
@@ -1829,10 +1904,8 @@ ring_buffer_iter_peek(struct ring_buffer_iter *iter, u64 *ts)
 	 * can have. Nesting 10 deep of interrupts is clearly
 	 * an anomaly.
 	 */
-	if (unlikely(++nr_loops > 10)) {
-		RB_WARN_ON(cpu_buffer, 1);
+	if (RB_WARN_ON(cpu_buffer, ++nr_loops > 10))
 		return NULL;
-	}
 
 	if (rb_per_cpu_empty(cpu_buffer))
 		return NULL;
@@ -1869,6 +1942,51 @@ ring_buffer_iter_peek(struct ring_buffer_iter *iter, u64 *ts)
 }
 
 /**
+ * ring_buffer_peek - peek at the next event to be read
+ * @buffer: The ring buffer to read
+ * @cpu: The cpu to peak at
+ * @ts: The timestamp counter of this event.
+ *
+ * This will return the event that will be read next, but does
+ * not consume the data.
+ */
+struct ring_buffer_event *
+ring_buffer_peek(struct ring_buffer *buffer, int cpu, u64 *ts)
+{
+	struct ring_buffer_per_cpu *cpu_buffer = buffer->buffers[cpu];
+	struct ring_buffer_event *event;
+	unsigned long flags;
+
+	spin_lock_irqsave(&cpu_buffer->reader_lock, flags);
+	event = rb_buffer_peek(buffer, cpu, ts);
+	spin_unlock_irqrestore(&cpu_buffer->reader_lock, flags);
+
+	return event;
+}
+
+/**
+ * ring_buffer_iter_peek - peek at the next event to be read
+ * @iter: The ring buffer iterator
+ * @ts: The timestamp counter of this event.
+ *
+ * This will return the event that will be read next, but does
+ * not increment the iterator.
+ */
+struct ring_buffer_event *
+ring_buffer_iter_peek(struct ring_buffer_iter *iter, u64 *ts)
+{
+	struct ring_buffer_per_cpu *cpu_buffer = iter->cpu_buffer;
+	struct ring_buffer_event *event;
+	unsigned long flags;
+
+	spin_lock_irqsave(&cpu_buffer->reader_lock, flags);
+	event = rb_iter_peek(iter, ts);
+	spin_unlock_irqrestore(&cpu_buffer->reader_lock, flags);
+
+	return event;
+}
+
+/**
  * ring_buffer_consume - return an event and consume it
  * @buffer: The ring buffer to get the next event from
  *
@@ -1879,19 +1997,24 @@ ring_buffer_iter_peek(struct ring_buffer_iter *iter, u64 *ts)
 struct ring_buffer_event *
 ring_buffer_consume(struct ring_buffer *buffer, int cpu, u64 *ts)
 {
-	struct ring_buffer_per_cpu *cpu_buffer;
+	struct ring_buffer_per_cpu *cpu_buffer = buffer->buffers[cpu];
 	struct ring_buffer_event *event;
+	unsigned long flags;
 
 	if (!cpu_isset(cpu, buffer->cpumask))
 		return NULL;
 
-	event = ring_buffer_peek(buffer, cpu, ts);
+	spin_lock_irqsave(&cpu_buffer->reader_lock, flags);
+
+	event = rb_buffer_peek(buffer, cpu, ts);
 	if (!event)
-		return NULL;
+		goto out;
 
-	cpu_buffer = buffer->buffers[cpu];
 	rb_advance_reader(cpu_buffer);
 
+ out:
+	spin_unlock_irqrestore(&cpu_buffer->reader_lock, flags);
+
 	return event;
 }
 
@@ -1928,9 +2051,11 @@ ring_buffer_read_start(struct ring_buffer *buffer, int cpu)
 	atomic_inc(&cpu_buffer->record_disabled);
 	synchronize_sched();
 
-	spin_lock_irqsave(&cpu_buffer->lock, flags);
-	ring_buffer_iter_reset(iter);
-	spin_unlock_irqrestore(&cpu_buffer->lock, flags);
+	spin_lock_irqsave(&cpu_buffer->reader_lock, flags);
+	__raw_spin_lock(&cpu_buffer->lock);
+	rb_iter_reset(iter);
+	__raw_spin_unlock(&cpu_buffer->lock);
+	spin_unlock_irqrestore(&cpu_buffer->reader_lock, flags);
 
 	return iter;
 }
@@ -1962,12 +2087,17 @@ struct ring_buffer_event *
 ring_buffer_read(struct ring_buffer_iter *iter, u64 *ts)
 {
 	struct ring_buffer_event *event;
+	struct ring_buffer_per_cpu *cpu_buffer = iter->cpu_buffer;
+	unsigned long flags;
 
-	event = ring_buffer_iter_peek(iter, ts);
+	spin_lock_irqsave(&cpu_buffer->reader_lock, flags);
+	event = rb_iter_peek(iter, ts);
 	if (!event)
-		return NULL;
+		goto out;
 
 	rb_advance_iter(iter);
+ out:
+	spin_unlock_irqrestore(&cpu_buffer->reader_lock, flags);
 
 	return event;
 }
@@ -1987,7 +2117,7 @@ rb_reset_cpu(struct ring_buffer_per_cpu *cpu_buffer)
 	cpu_buffer->head_page
 		= list_entry(cpu_buffer->pages.next, struct buffer_page, list);
 	local_set(&cpu_buffer->head_page->write, 0);
-	local_set(&cpu_buffer->head_page->commit, 0);
+	local_set(&cpu_buffer->head_page->page->commit, 0);
 
 	cpu_buffer->head_page->read = 0;
 
@@ -1996,7 +2126,7 @@ rb_reset_cpu(struct ring_buffer_per_cpu *cpu_buffer)
 
 	INIT_LIST_HEAD(&cpu_buffer->reader_page->list);
 	local_set(&cpu_buffer->reader_page->write, 0);
-	local_set(&cpu_buffer->reader_page->commit, 0);
+	local_set(&cpu_buffer->reader_page->page->commit, 0);
 	cpu_buffer->reader_page->read = 0;
 
 	cpu_buffer->overrun = 0;
@@ -2016,11 +2146,15 @@ void ring_buffer_reset_cpu(struct ring_buffer *buffer, int cpu)
 	if (!cpu_isset(cpu, buffer->cpumask))
 		return;
 
-	spin_lock_irqsave(&cpu_buffer->lock, flags);
+	spin_lock_irqsave(&cpu_buffer->reader_lock, flags);
+
+	__raw_spin_lock(&cpu_buffer->lock);
 
 	rb_reset_cpu(cpu_buffer);
 
-	spin_unlock_irqrestore(&cpu_buffer->lock, flags);
+	__raw_spin_unlock(&cpu_buffer->lock);
+
+	spin_unlock_irqrestore(&cpu_buffer->reader_lock, flags);
 }
 
 /**
@@ -2090,8 +2224,7 @@ int ring_buffer_swap_cpu(struct ring_buffer *buffer_a,
 		return -EINVAL;
 
 	/* At least make sure the two buffers are somewhat the same */
-	if (buffer_a->size != buffer_b->size ||
-	    buffer_a->pages != buffer_b->pages)
+	if (buffer_a->pages != buffer_b->pages)
 		return -EINVAL;
 
 	cpu_buffer_a = buffer_a->buffers[cpu];
@@ -2118,16 +2251,178 @@ int ring_buffer_swap_cpu(struct ring_buffer *buffer_a,
 	return 0;
 }
 
+static void rb_remove_entries(struct ring_buffer_per_cpu *cpu_buffer,
+			      struct buffer_data_page *bpage)
+{
+	struct ring_buffer_event *event;
+	unsigned long head;
+
+	__raw_spin_lock(&cpu_buffer->lock);
+	for (head = 0; head < local_read(&bpage->commit);
+	     head += rb_event_length(event)) {
+
+		event = __rb_data_page_index(bpage, head);
+		if (RB_WARN_ON(cpu_buffer, rb_null_event(event)))
+			return;
+		/* Only count data entries */
+		if (event->type != RINGBUF_TYPE_DATA)
+			continue;
+		cpu_buffer->entries--;
+	}
+	__raw_spin_unlock(&cpu_buffer->lock);
+}
+
+/**
+ * ring_buffer_alloc_read_page - allocate a page to read from buffer
+ * @buffer: the buffer to allocate for.
+ *
+ * This function is used in conjunction with ring_buffer_read_page.
+ * When reading a full page from the ring buffer, these functions
+ * can be used to speed up the process. The calling function should
+ * allocate a few pages first with this function. Then when it
+ * needs to get pages from the ring buffer, it passes the result
+ * of this function into ring_buffer_read_page, which will swap
+ * the page that was allocated, with the read page of the buffer.
+ *
+ * Returns:
+ *  The page allocated, or NULL on error.
+ */
+void *ring_buffer_alloc_read_page(struct ring_buffer *buffer)
+{
+	unsigned long addr;
+	struct buffer_data_page *bpage;
+
+	addr = __get_free_page(GFP_KERNEL);
+	if (!addr)
+		return NULL;
+
+	bpage = (void *)addr;
+
+	return bpage;
+}
+
+/**
+ * ring_buffer_free_read_page - free an allocated read page
+ * @buffer: the buffer the page was allocate for
+ * @data: the page to free
+ *
+ * Free a page allocated from ring_buffer_alloc_read_page.
+ */
+void ring_buffer_free_read_page(struct ring_buffer *buffer, void *data)
+{
+	free_page((unsigned long)data);
+}
+
+/**
+ * ring_buffer_read_page - extract a page from the ring buffer
+ * @buffer: buffer to extract from
+ * @data_page: the page to use allocated from ring_buffer_alloc_read_page
+ * @cpu: the cpu of the buffer to extract
+ * @full: should the extraction only happen when the page is full.
+ *
+ * This function will pull out a page from the ring buffer and consume it.
+ * @data_page must be the address of the variable that was returned
+ * from ring_buffer_alloc_read_page. This is because the page might be used
+ * to swap with a page in the ring buffer.
+ *
+ * for example:
+ *	rpage = ring_buffer_alloc_page(buffer);
+ *	if (!rpage)
+ *		return error;
+ *	ret = ring_buffer_read_page(buffer, &rpage, cpu, 0);
+ *	if (ret)
+ *		process_page(rpage);
+ *
+ * When @full is set, the function will not return true unless
+ * the writer is off the reader page.
+ *
+ * Note: it is up to the calling functions to handle sleeps and wakeups.
+ *  The ring buffer can be used anywhere in the kernel and can not
+ *  blindly call wake_up. The layer that uses the ring buffer must be
+ *  responsible for that.
+ *
+ * Returns:
+ *  1 if data has been transferred
+ *  0 if no data has been transferred.
+ */
+int ring_buffer_read_page(struct ring_buffer *buffer,
+			    void **data_page, int cpu, int full)
+{
+	struct ring_buffer_per_cpu *cpu_buffer = buffer->buffers[cpu];
+	struct ring_buffer_event *event;
+	struct buffer_data_page *bpage;
+	unsigned long flags;
+	int ret = 0;
+
+	if (!data_page)
+		return 0;
+
+	bpage = *data_page;
+	if (!bpage)
+		return 0;
+
+	spin_lock_irqsave(&cpu_buffer->reader_lock, flags);
+
+	/*
+	 * rb_buffer_peek will get the next ring buffer if
+	 * the current reader page is empty.
+	 */
+	event = rb_buffer_peek(buffer, cpu, NULL);
+	if (!event)
+		goto out;
+
+	/* check for data */
+	if (!local_read(&cpu_buffer->reader_page->page->commit))
+		goto out;
+	/*
+	 * If the writer is already off of the read page, then simply
+	 * switch the read page with the given page. Otherwise
+	 * we need to copy the data from the reader to the writer.
+	 */
+	if (cpu_buffer->reader_page == cpu_buffer->commit_page) {
+		unsigned int read = cpu_buffer->reader_page->read;
+
+		if (full)
+			goto out;
+		/* The writer is still on the reader page, we must copy */
+		bpage = cpu_buffer->reader_page->page;
+		memcpy(bpage->data,
+		       cpu_buffer->reader_page->page->data + read,
+		       local_read(&bpage->commit) - read);
+
+		/* consume what was read */
+		cpu_buffer->reader_page += read;
+
+	} else {
+		/* swap the pages */
+		rb_init_page(bpage);
+		bpage = cpu_buffer->reader_page->page;
+		cpu_buffer->reader_page->page = *data_page;
+		cpu_buffer->reader_page->read = 0;
+		*data_page = bpage;
+	}
+	ret = 1;
+
+	/* update the entry counter */
+	rb_remove_entries(cpu_buffer, bpage);
+ out:
+	spin_unlock_irqrestore(&cpu_buffer->reader_lock, flags);
+
+	return ret;
+}
+
 static ssize_t
 rb_simple_read(struct file *filp, char __user *ubuf,
 	       size_t cnt, loff_t *ppos)
 {
-	int *p = filp->private_data;
+	long *p = filp->private_data;
 	char buf[64];
 	int r;
 
-	/* !ring_buffers_off == tracing_on */
-	r = sprintf(buf, "%d\n", !*p);
+	if (test_bit(RB_BUFFERS_DISABLED_BIT, p))
+		r = sprintf(buf, "permanently disabled\n");
+	else
+		r = sprintf(buf, "%d\n", test_bit(RB_BUFFERS_ON_BIT, p));
 
 	return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
 }
@@ -2136,7 +2431,7 @@ static ssize_t
 rb_simple_write(struct file *filp, const char __user *ubuf,
 		size_t cnt, loff_t *ppos)
 {
-	int *p = filp->private_data;
+	long *p = filp->private_data;
 	char buf[64];
 	long val;
 	int ret;
@@ -2153,8 +2448,10 @@ rb_simple_write(struct file *filp, const char __user *ubuf,
 	if (ret < 0)
 		return ret;
 
-	/* !ring_buffers_off == tracing_on */
-	*p = !val;
+	if (val)
+		set_bit(RB_BUFFERS_ON_BIT, p);
+	else
+		clear_bit(RB_BUFFERS_ON_BIT, p);
 
 	(*ppos)++;
 
@@ -2176,7 +2473,7 @@ static __init int rb_init_debugfs(void)
 	d_tracer = tracing_init_dentry();
 
 	entry = debugfs_create_file("tracing_on", 0644, d_tracer,
-				    &ring_buffers_off, &rb_simple_fops);
+				    &ring_buffer_flags, &rb_simple_fops);
 	if (!entry)
 		pr_warning("Could not create debugfs 'tracing_on' entry\n");
 
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 1ee9e4e..f4bb380 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -30,6 +30,7 @@
 #include <linux/gfp.h>
 #include <linux/fs.h>
 #include <linux/kprobes.h>
+#include <linux/seq_file.h>
 #include <linux/writeback.h>
 
 #include <linux/stacktrace.h>
@@ -43,6 +44,38 @@
 unsigned long __read_mostly	tracing_max_latency = (cycle_t)ULONG_MAX;
 unsigned long __read_mostly	tracing_thresh;
 
+/*
+ * We need to change this state when a selftest is running.
+ * A selftest will lurk into the ring-buffer to count the
+ * entries inserted during the selftest although some concurrent
+ * insertions into the ring-buffer such as ftrace_printk could occurred
+ * at the same time, giving false positive or negative results.
+ */
+static bool __read_mostly tracing_selftest_running;
+
+/* For tracers that don't implement custom flags */
+static struct tracer_opt dummy_tracer_opt[] = {
+	{ }
+};
+
+static struct tracer_flags dummy_tracer_flags = {
+	.val = 0,
+	.opts = dummy_tracer_opt
+};
+
+static int dummy_set_flag(u32 old_flags, u32 bit, int set)
+{
+	return 0;
+}
+
+/*
+ * Kill all tracing for good (never come back).
+ * It is initialized to 1 but will turn to zero if the initialization
+ * of the tracer is successful. But that is the only place that sets
+ * this back to zero.
+ */
+int tracing_disabled = 1;
+
 static DEFINE_PER_CPU(local_t, ftrace_cpu_disabled);
 
 static inline void ftrace_disable_cpu(void)
@@ -62,7 +95,36 @@ static cpumask_t __read_mostly		tracing_buffer_mask;
 #define for_each_tracing_cpu(cpu)	\
 	for_each_cpu_mask(cpu, tracing_buffer_mask)
 
-static int tracing_disabled = 1;
+/*
+ * ftrace_dump_on_oops - variable to dump ftrace buffer on oops
+ *
+ * If there is an oops (or kernel panic) and the ftrace_dump_on_oops
+ * is set, then ftrace_dump is called. This will output the contents
+ * of the ftrace buffers to the console.  This is very useful for
+ * capturing traces that lead to crashes and outputing it to a
+ * serial console.
+ *
+ * It is default off, but you can enable it with either specifying
+ * "ftrace_dump_on_oops" in the kernel command line, or setting
+ * /proc/sys/kernel/ftrace_dump_on_oops to true.
+ */
+int ftrace_dump_on_oops;
+
+static int tracing_set_tracer(char *buf);
+
+static int __init set_ftrace(char *str)
+{
+	tracing_set_tracer(str);
+	return 1;
+}
+__setup("ftrace", set_ftrace);
+
+static int __init set_ftrace_dump_on_oops(char *str)
+{
+	ftrace_dump_on_oops = 1;
+	return 1;
+}
+__setup("ftrace_dump_on_oops", set_ftrace_dump_on_oops);
 
 long
 ns2usecs(cycle_t nsec)
@@ -112,6 +174,19 @@ static DEFINE_PER_CPU(struct trace_array_cpu, max_data);
 /* tracer_enabled is used to toggle activation of a tracer */
 static int			tracer_enabled = 1;
 
+/**
+ * tracing_is_enabled - return tracer_enabled status
+ *
+ * This function is used by other tracers to know the status
+ * of the tracer_enabled flag.  Tracers may use this function
+ * to know if it should enable their features when starting
+ * up. See irqsoff tracer for an example (start_irqsoff_tracer).
+ */
+int tracing_is_enabled(void)
+{
+	return tracer_enabled;
+}
+
 /* function tracing enabled */
 int				ftrace_function_enabled;
 
@@ -153,8 +228,9 @@ static DEFINE_MUTEX(trace_types_lock);
 /* trace_wait is a waitqueue for tasks blocked on trace_poll */
 static DECLARE_WAIT_QUEUE_HEAD(trace_wait);
 
-/* trace_flags holds iter_ctrl options */
-unsigned long trace_flags = TRACE_ITER_PRINT_PARENT;
+/* trace_flags holds trace_options default values */
+unsigned long trace_flags = TRACE_ITER_PRINT_PARENT | TRACE_ITER_PRINTK |
+	TRACE_ITER_ANNOTATE;
 
 /**
  * trace_wake_up - wake up tasks waiting for trace input
@@ -193,13 +269,6 @@ unsigned long nsecs_to_usecs(unsigned long nsecs)
 	return nsecs / 1000;
 }
 
-/*
- * TRACE_ITER_SYM_MASK masks the options in trace_flags that
- * control the output of kernel symbols.
- */
-#define TRACE_ITER_SYM_MASK \
-	(TRACE_ITER_PRINT_PARENT|TRACE_ITER_SYM_OFFSET|TRACE_ITER_SYM_ADDR)
-
 /* These must match the bit postions in trace_iterator_flags */
 static const char *trace_options[] = {
 	"print-parent",
@@ -213,6 +282,12 @@ static const char *trace_options[] = {
 	"stacktrace",
 	"sched-tree",
 	"ftrace_printk",
+	"ftrace_preempt",
+	"branch",
+	"annotate",
+	"userstacktrace",
+	"sym-userobj",
+	"printk-msg-only",
 	NULL
 };
 
@@ -359,6 +434,28 @@ trace_seq_putmem_hex(struct trace_seq *s, void *mem, size_t len)
 	return trace_seq_putmem(s, hex, j);
 }
 
+static int
+trace_seq_path(struct trace_seq *s, struct path *path)
+{
+	unsigned char *p;
+
+	if (s->len >= (PAGE_SIZE - 1))
+		return 0;
+	p = d_path(path, s->buffer + s->len, PAGE_SIZE - s->len);
+	if (!IS_ERR(p)) {
+		p = mangle_path(s->buffer + s->len, p, "\n");
+		if (p) {
+			s->len = p - s->buffer;
+			return 1;
+		}
+	} else {
+		s->buffer[s->len++] = '?';
+		return 1;
+	}
+
+	return 0;
+}
+
 static void
 trace_seq_reset(struct trace_seq *s)
 {
@@ -470,7 +567,17 @@ int register_tracer(struct tracer *type)
 		return -1;
 	}
 
+	/*
+	 * When this gets called we hold the BKL which means that
+	 * preemption is disabled. Various trace selftests however
+	 * need to disable and enable preemption for successful tests.
+	 * So we drop the BKL here and grab it after the tests again.
+	 */
+	unlock_kernel();
 	mutex_lock(&trace_types_lock);
+
+	tracing_selftest_running = true;
+
 	for (t = trace_types; t; t = t->next) {
 		if (strcmp(type->name, t->name) == 0) {
 			/* already found */
@@ -481,12 +588,20 @@ int register_tracer(struct tracer *type)
 		}
 	}
 
+	if (!type->set_flag)
+		type->set_flag = &dummy_set_flag;
+	if (!type->flags)
+		type->flags = &dummy_tracer_flags;
+	else
+		if (!type->flags->opts)
+			type->flags->opts = dummy_tracer_opt;
+
 #ifdef CONFIG_FTRACE_STARTUP_TEST
 	if (type->selftest) {
 		struct tracer *saved_tracer = current_trace;
 		struct trace_array *tr = &global_trace;
-		int saved_ctrl = tr->ctrl;
 		int i;
+
 		/*
 		 * Run a selftest on this tracer.
 		 * Here we reset the trace buffer, and set the current
@@ -494,25 +609,23 @@ int register_tracer(struct tracer *type)
 		 * internal tracing to verify that everything is in order.
 		 * If we fail, we do not register this tracer.
 		 */
-		for_each_tracing_cpu(i) {
+		for_each_tracing_cpu(i)
 			tracing_reset(tr, i);
-		}
+
 		current_trace = type;
-		tr->ctrl = 0;
 		/* the test is responsible for initializing and enabling */
 		pr_info("Testing tracer %s: ", type->name);
 		ret = type->selftest(type, tr);
 		/* the test is responsible for resetting too */
 		current_trace = saved_tracer;
-		tr->ctrl = saved_ctrl;
 		if (ret) {
 			printk(KERN_CONT "FAILED!\n");
 			goto out;
 		}
 		/* Only reset on passing, to avoid touching corrupted buffers */
-		for_each_tracing_cpu(i) {
+		for_each_tracing_cpu(i)
 			tracing_reset(tr, i);
-		}
+
 		printk(KERN_CONT "PASSED\n");
 	}
 #endif
@@ -524,7 +637,9 @@ int register_tracer(struct tracer *type)
 		max_tracer_type_len = len;
 
  out:
+	tracing_selftest_running = false;
 	mutex_unlock(&trace_types_lock);
+	lock_kernel();
 
 	return ret;
 }
@@ -564,6 +679,16 @@ void tracing_reset(struct trace_array *tr, int cpu)
 	ftrace_enable_cpu();
 }
 
+void tracing_reset_online_cpus(struct trace_array *tr)
+{
+	int cpu;
+
+	tr->time_start = ftrace_now(tr->cpu);
+
+	for_each_online_cpu(cpu)
+		tracing_reset(tr, cpu);
+}
+
 #define SAVED_CMDLINES 128
 static unsigned map_pid_to_cmdline[PID_MAX_DEFAULT+1];
 static unsigned map_cmdline_to_pid[SAVED_CMDLINES];
@@ -581,6 +706,91 @@ static void trace_init_cmdlines(void)
 	cmdline_idx = 0;
 }
 
+static int trace_stop_count;
+static DEFINE_SPINLOCK(tracing_start_lock);
+
+/**
+ * ftrace_off_permanent - disable all ftrace code permanently
+ *
+ * This should only be called when a serious anomally has
+ * been detected.  This will turn off the function tracing,
+ * ring buffers, and other tracing utilites. It takes no
+ * locks and can be called from any context.
+ */
+void ftrace_off_permanent(void)
+{
+	tracing_disabled = 1;
+	ftrace_stop();
+	tracing_off_permanent();
+}
+
+/**
+ * tracing_start - quick start of the tracer
+ *
+ * If tracing is enabled but was stopped by tracing_stop,
+ * this will start the tracer back up.
+ */
+void tracing_start(void)
+{
+	struct ring_buffer *buffer;
+	unsigned long flags;
+
+	if (tracing_disabled)
+		return;
+
+	spin_lock_irqsave(&tracing_start_lock, flags);
+	if (--trace_stop_count)
+		goto out;
+
+	if (trace_stop_count < 0) {
+		/* Someone screwed up their debugging */
+		WARN_ON_ONCE(1);
+		trace_stop_count = 0;
+		goto out;
+	}
+
+
+	buffer = global_trace.buffer;
+	if (buffer)
+		ring_buffer_record_enable(buffer);
+
+	buffer = max_tr.buffer;
+	if (buffer)
+		ring_buffer_record_enable(buffer);
+
+	ftrace_start();
+ out:
+	spin_unlock_irqrestore(&tracing_start_lock, flags);
+}
+
+/**
+ * tracing_stop - quick stop of the tracer
+ *
+ * Light weight way to stop tracing. Use in conjunction with
+ * tracing_start.
+ */
+void tracing_stop(void)
+{
+	struct ring_buffer *buffer;
+	unsigned long flags;
+
+	ftrace_stop();
+	spin_lock_irqsave(&tracing_start_lock, flags);
+	if (trace_stop_count++)
+		goto out;
+
+	buffer = global_trace.buffer;
+	if (buffer)
+		ring_buffer_record_disable(buffer);
+
+	buffer = max_tr.buffer;
+	if (buffer)
+		ring_buffer_record_disable(buffer);
+
+ out:
+	spin_unlock_irqrestore(&tracing_start_lock, flags);
+}
+
 void trace_stop_cmdline_recording(void);
 
 static void trace_save_cmdline(struct task_struct *tsk)
@@ -618,7 +828,7 @@ static void trace_save_cmdline(struct task_struct *tsk)
 	spin_unlock(&trace_cmdline_lock);
 }
 
-static char *trace_find_cmdline(int pid)
+char *trace_find_cmdline(int pid)
 {
 	char *cmdline = "<...>";
 	unsigned map;
@@ -655,6 +865,7 @@ tracing_generic_entry_update(struct trace_entry *entry, unsigned long flags,
 
 	entry->preempt_count		= pc & 0xff;
 	entry->pid			= (tsk) ? tsk->pid : 0;
+	entry->tgid               	= (tsk) ? tsk->tgid : 0;
 	entry->flags =
 #ifdef CONFIG_TRACE_IRQFLAGS_SUPPORT
 		(irqs_disabled_flags(flags) ? TRACE_FLAG_IRQS_OFF : 0) |
@@ -691,6 +902,56 @@ trace_function(struct trace_array *tr, struct trace_array_cpu *data,
 	ring_buffer_unlock_commit(tr->buffer, event, irq_flags);
 }
 
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+static void __trace_graph_entry(struct trace_array *tr,
+				struct trace_array_cpu *data,
+				struct ftrace_graph_ent *trace,
+				unsigned long flags,
+				int pc)
+{
+	struct ring_buffer_event *event;
+	struct ftrace_graph_ent_entry *entry;
+	unsigned long irq_flags;
+
+	if (unlikely(local_read(&__get_cpu_var(ftrace_cpu_disabled))))
+		return;
+
+	event = ring_buffer_lock_reserve(global_trace.buffer, sizeof(*entry),
+					 &irq_flags);
+	if (!event)
+		return;
+	entry	= ring_buffer_event_data(event);
+	tracing_generic_entry_update(&entry->ent, flags, pc);
+	entry->ent.type			= TRACE_GRAPH_ENT;
+	entry->graph_ent			= *trace;
+	ring_buffer_unlock_commit(global_trace.buffer, event, irq_flags);
+}
+
+static void __trace_graph_return(struct trace_array *tr,
+				struct trace_array_cpu *data,
+				struct ftrace_graph_ret *trace,
+				unsigned long flags,
+				int pc)
+{
+	struct ring_buffer_event *event;
+	struct ftrace_graph_ret_entry *entry;
+	unsigned long irq_flags;
+
+	if (unlikely(local_read(&__get_cpu_var(ftrace_cpu_disabled))))
+		return;
+
+	event = ring_buffer_lock_reserve(global_trace.buffer, sizeof(*entry),
+					 &irq_flags);
+	if (!event)
+		return;
+	entry	= ring_buffer_event_data(event);
+	tracing_generic_entry_update(&entry->ent, flags, pc);
+	entry->ent.type			= TRACE_GRAPH_RET;
+	entry->ret				= *trace;
+	ring_buffer_unlock_commit(global_trace.buffer, event, irq_flags);
+}
+#endif
+
 void
 ftrace(struct trace_array *tr, struct trace_array_cpu *data,
        unsigned long ip, unsigned long parent_ip, unsigned long flags,
@@ -742,6 +1003,46 @@ void __trace_stack(struct trace_array *tr,
 	ftrace_trace_stack(tr, data, flags, skip, preempt_count());
 }
 
+static void ftrace_trace_userstack(struct trace_array *tr,
+		   struct trace_array_cpu *data,
+		   unsigned long flags, int pc)
+{
+#ifdef CONFIG_STACKTRACE
+	struct ring_buffer_event *event;
+	struct userstack_entry *entry;
+	struct stack_trace trace;
+	unsigned long irq_flags;
+
+	if (!(trace_flags & TRACE_ITER_USERSTACKTRACE))
+		return;
+
+	event = ring_buffer_lock_reserve(tr->buffer, sizeof(*entry),
+					 &irq_flags);
+	if (!event)
+		return;
+	entry	= ring_buffer_event_data(event);
+	tracing_generic_entry_update(&entry->ent, flags, pc);
+	entry->ent.type		= TRACE_USER_STACK;
+
+	memset(&entry->caller, 0, sizeof(entry->caller));
+
+	trace.nr_entries	= 0;
+	trace.max_entries	= FTRACE_STACK_ENTRIES;
+	trace.skip		= 0;
+	trace.entries		= entry->caller;
+
+	save_stack_trace_user(&trace);
+	ring_buffer_unlock_commit(tr->buffer, event, irq_flags);
+#endif
+}
+
+void __trace_userstack(struct trace_array *tr,
+		   struct trace_array_cpu *data,
+		   unsigned long flags)
+{
+	ftrace_trace_userstack(tr, data, flags, preempt_count());
+}
+
 static void
 ftrace_trace_special(void *__tr, void *__data,
 		     unsigned long arg1, unsigned long arg2, unsigned long arg3,
@@ -765,6 +1066,7 @@ ftrace_trace_special(void *__tr, void *__data,
 	entry->arg3			= arg3;
 	ring_buffer_unlock_commit(tr->buffer, event, irq_flags);
 	ftrace_trace_stack(tr, data, irq_flags, 4, pc);
+	ftrace_trace_userstack(tr, data, irq_flags, pc);
 
 	trace_wake_up();
 }
@@ -803,6 +1105,7 @@ tracing_sched_switch_trace(struct trace_array *tr,
 	entry->next_cpu	= task_cpu(next);
 	ring_buffer_unlock_commit(tr->buffer, event, irq_flags);
 	ftrace_trace_stack(tr, data, flags, 5, pc);
+	ftrace_trace_userstack(tr, data, flags, pc);
 }
 
 void
@@ -832,6 +1135,7 @@ tracing_sched_wakeup_trace(struct trace_array *tr,
 	entry->next_cpu			= task_cpu(wakee);
 	ring_buffer_unlock_commit(tr->buffer, event, irq_flags);
 	ftrace_trace_stack(tr, data, flags, 6, pc);
+	ftrace_trace_userstack(tr, data, flags, pc);
 
 	trace_wake_up();
 }
@@ -841,26 +1145,28 @@ ftrace_special(unsigned long arg1, unsigned long arg2, unsigned long arg3)
 {
 	struct trace_array *tr = &global_trace;
 	struct trace_array_cpu *data;
+	unsigned long flags;
 	int cpu;
 	int pc;
 
-	if (tracing_disabled || !tr->ctrl)
+	if (tracing_disabled)
 		return;
 
 	pc = preempt_count();
-	preempt_disable_notrace();
+	local_irq_save(flags);
 	cpu = raw_smp_processor_id();
 	data = tr->data[cpu];
 
-	if (likely(!atomic_read(&data->disabled)))
+	if (likely(atomic_inc_return(&data->disabled) == 1))
 		ftrace_trace_special(tr, data, arg1, arg2, arg3, pc);
 
-	preempt_enable_notrace();
+	atomic_dec(&data->disabled);
+	local_irq_restore(flags);
 }
 
 #ifdef CONFIG_FUNCTION_TRACER
 static void
-function_trace_call(unsigned long ip, unsigned long parent_ip)
+function_trace_call_preempt_only(unsigned long ip, unsigned long parent_ip)
 {
 	struct trace_array *tr = &global_trace;
 	struct trace_array_cpu *data;
@@ -873,8 +1179,7 @@ function_trace_call(unsigned long ip, unsigned long parent_ip)
 		return;
 
 	pc = preempt_count();
-	resched = need_resched();
-	preempt_disable_notrace();
+	resched = ftrace_preempt_disable();
 	local_save_flags(flags);
 	cpu = raw_smp_processor_id();
 	data = tr->data[cpu];
@@ -884,12 +1189,97 @@ function_trace_call(unsigned long ip, unsigned long parent_ip)
 		trace_function(tr, data, ip, parent_ip, flags, pc);
 
 	atomic_dec(&data->disabled);
-	if (resched)
-		preempt_enable_no_resched_notrace();
-	else
-		preempt_enable_notrace();
+	ftrace_preempt_enable(resched);
 }
 
+static void
+function_trace_call(unsigned long ip, unsigned long parent_ip)
+{
+	struct trace_array *tr = &global_trace;
+	struct trace_array_cpu *data;
+	unsigned long flags;
+	long disabled;
+	int cpu;
+	int pc;
+
+	if (unlikely(!ftrace_function_enabled))
+		return;
+
+	/*
+	 * Need to use raw, since this must be called before the
+	 * recursive protection is performed.
+	 */
+	local_irq_save(flags);
+	cpu = raw_smp_processor_id();
+	data = tr->data[cpu];
+	disabled = atomic_inc_return(&data->disabled);
+
+	if (likely(disabled == 1)) {
+		pc = preempt_count();
+		trace_function(tr, data, ip, parent_ip, flags, pc);
+	}
+
+	atomic_dec(&data->disabled);
+	local_irq_restore(flags);
+}
+
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+int trace_graph_entry(struct ftrace_graph_ent *trace)
+{
+	struct trace_array *tr = &global_trace;
+	struct trace_array_cpu *data;
+	unsigned long flags;
+	long disabled;
+	int cpu;
+	int pc;
+
+	if (!ftrace_trace_task(current))
+		return 0;
+
+	if (!ftrace_graph_addr(trace->func))
+		return 0;
+
+	local_irq_save(flags);
+	cpu = raw_smp_processor_id();
+	data = tr->data[cpu];
+	disabled = atomic_inc_return(&data->disabled);
+	if (likely(disabled == 1)) {
+		pc = preempt_count();
+		__trace_graph_entry(tr, data, trace, flags, pc);
+	}
+	/* Only do the atomic if it is not already set */
+	if (!test_tsk_trace_graph(current))
+		set_tsk_trace_graph(current);
+	atomic_dec(&data->disabled);
+	local_irq_restore(flags);
+
+	return 1;
+}
+
+void trace_graph_return(struct ftrace_graph_ret *trace)
+{
+	struct trace_array *tr = &global_trace;
+	struct trace_array_cpu *data;
+	unsigned long flags;
+	long disabled;
+	int cpu;
+	int pc;
+
+	local_irq_save(flags);
+	cpu = raw_smp_processor_id();
+	data = tr->data[cpu];
+	disabled = atomic_inc_return(&data->disabled);
+	if (likely(disabled == 1)) {
+		pc = preempt_count();
+		__trace_graph_return(tr, data, trace, flags, pc);
+	}
+	if (!trace->depth)
+		clear_tsk_trace_graph(current);
+	atomic_dec(&data->disabled);
+	local_irq_restore(flags);
+}
+#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
+
 static struct ftrace_ops trace_ops __read_mostly =
 {
 	.func = function_trace_call,
@@ -898,9 +1288,14 @@ static struct ftrace_ops trace_ops __read_mostly =
 void tracing_start_function_trace(void)
 {
 	ftrace_function_enabled = 0;
+
+	if (trace_flags & TRACE_ITER_PREEMPTONLY)
+		trace_ops.func = function_trace_call_preempt_only;
+	else
+		trace_ops.func = function_trace_call;
+
 	register_ftrace_function(&trace_ops);
-	if (tracer_enabled)
-		ftrace_function_enabled = 1;
+	ftrace_function_enabled = 1;
 }
 
 void tracing_stop_function_trace(void)
@@ -912,6 +1307,7 @@ void tracing_stop_function_trace(void)
 
 enum trace_file_type {
 	TRACE_FILE_LAT_FMT	= 1,
+	TRACE_FILE_ANNOTATE	= 2,
 };
 
 static void trace_iterator_increment(struct trace_iterator *iter, int cpu)
@@ -1047,10 +1443,6 @@ static void *s_start(struct seq_file *m, loff_t *pos)
 
 	atomic_inc(&trace_record_cmdline_disabled);
 
-	/* let the tracer grab locks here if needed */
-	if (current_trace->start)
-		current_trace->start(iter);
-
 	if (*pos != iter->pos) {
 		iter->ent = NULL;
 		iter->cpu = 0;
@@ -1077,14 +1469,7 @@ static void *s_start(struct seq_file *m, loff_t *pos)
 
 static void s_stop(struct seq_file *m, void *p)
 {
-	struct trace_iterator *iter = m->private;
-
 	atomic_dec(&trace_record_cmdline_disabled);
-
-	/* let the tracer release locks here if needed */
-	if (current_trace && current_trace == iter->trace && iter->trace->stop)
-		iter->trace->stop(iter);
-
 	mutex_unlock(&trace_types_lock);
 }
 
@@ -1143,7 +1528,7 @@ seq_print_sym_offset(struct trace_seq *s, const char *fmt,
 # define IP_FMT "%016lx"
 #endif
 
-static int
+int
 seq_print_ip_sym(struct trace_seq *s, unsigned long ip, unsigned long sym_flags)
 {
 	int ret;
@@ -1164,6 +1549,78 @@ seq_print_ip_sym(struct trace_seq *s, unsigned long ip, unsigned long sym_flags)
 	return ret;
 }
 
+static inline int seq_print_user_ip(struct trace_seq *s, struct mm_struct *mm,
+				    unsigned long ip, unsigned long sym_flags)
+{
+	struct file *file = NULL;
+	unsigned long vmstart = 0;
+	int ret = 1;
+
+	if (mm) {
+		const struct vm_area_struct *vma;
+
+		down_read(&mm->mmap_sem);
+		vma = find_vma(mm, ip);
+		if (vma) {
+			file = vma->vm_file;
+			vmstart = vma->vm_start;
+		}
+		if (file) {
+			ret = trace_seq_path(s, &file->f_path);
+			if (ret)
+				ret = trace_seq_printf(s, "[+0x%lx]", ip - vmstart);
+		}
+		up_read(&mm->mmap_sem);
+	}
+	if (ret && ((sym_flags & TRACE_ITER_SYM_ADDR) || !file))
+		ret = trace_seq_printf(s, " <" IP_FMT ">", ip);
+	return ret;
+}
+
+static int
+seq_print_userip_objs(const struct userstack_entry *entry, struct trace_seq *s,
+		      unsigned long sym_flags)
+{
+	struct mm_struct *mm = NULL;
+	int ret = 1;
+	unsigned int i;
+
+	if (trace_flags & TRACE_ITER_SYM_USEROBJ) {
+		struct task_struct *task;
+		/*
+		 * we do the lookup on the thread group leader,
+		 * since individual threads might have already quit!
+		 */
+		rcu_read_lock();
+		task = find_task_by_vpid(entry->ent.tgid);
+		if (task)
+			mm = get_task_mm(task);
+		rcu_read_unlock();
+	}
+
+	for (i = 0; i < FTRACE_STACK_ENTRIES; i++) {
+		unsigned long ip = entry->caller[i];
+
+		if (ip == ULONG_MAX || !ret)
+			break;
+		if (i && ret)
+			ret = trace_seq_puts(s, " <- ");
+		if (!ip) {
+			if (ret)
+				ret = trace_seq_puts(s, "??");
+			continue;
+		}
+		if (!ret)
+			break;
+		if (ret)
+			ret = seq_print_user_ip(s, mm, ip, sym_flags);
+	}
+
+	if (mm)
+		mmput(mm);
+	return ret;
+}
+
 static void print_lat_help_header(struct seq_file *m)
 {
 	seq_puts(m, "#                  _------=> CPU#            \n");
@@ -1301,6 +1758,13 @@ lat_print_timestamp(struct trace_seq *s, u64 abs_usecs,
 
 static const char state_to_char[] = TASK_STATE_TO_CHAR_STR;
 
+static int task_state_char(unsigned long state)
+{
+	int bit = state ? __ffs(state) + 1 : 0;
+
+	return bit < sizeof(state_to_char) - 1 ? state_to_char[bit] : '?';
+}
+
 /*
  * The message is supposed to contain an ending newline.
  * If the printing stops prematurely, try to add a newline of our own.
@@ -1338,6 +1802,23 @@ void trace_seq_print_cont(struct trace_seq *s, struct trace_iterator *iter)
 		trace_seq_putc(s, '\n');
 }
 
+static void test_cpu_buff_start(struct trace_iterator *iter)
+{
+	struct trace_seq *s = &iter->seq;
+
+	if (!(trace_flags & TRACE_ITER_ANNOTATE))
+		return;
+
+	if (!(iter->iter_flags & TRACE_FILE_ANNOTATE))
+		return;
+
+	if (cpu_isset(iter->cpu, iter->started))
+		return;
+
+	cpu_set(iter->cpu, iter->started);
+	trace_seq_printf(s, "##### CPU %u buffer started ####\n", iter->cpu);
+}
+
 static enum print_line_t
 print_lat_fmt(struct trace_iterator *iter, unsigned int trace_idx, int cpu)
 {
@@ -1352,11 +1833,12 @@ print_lat_fmt(struct trace_iterator *iter, unsigned int trace_idx, int cpu)
 	char *comm;
 	int S, T;
 	int i;
-	unsigned state;
 
 	if (entry->type == TRACE_CONT)
 		return TRACE_TYPE_HANDLED;
 
+	test_cpu_buff_start(iter);
+
 	next_entry = find_next_entry(iter, NULL, &next_ts);
 	if (!next_entry)
 		next_ts = iter->ts;
@@ -1396,12 +1878,8 @@ print_lat_fmt(struct trace_iterator *iter, unsigned int trace_idx, int cpu)
 
 		trace_assign_type(field, entry);
 
-		T = field->next_state < sizeof(state_to_char) ?
-			state_to_char[field->next_state] : 'X';
-
-		state = field->prev_state ?
-			__ffs(field->prev_state) + 1 : 0;
-		S = state < sizeof(state_to_char) - 1 ? state_to_char[state] : 'X';
+		T = task_state_char(field->next_state);
+		S = task_state_char(field->prev_state);
 		comm = trace_find_cmdline(field->next_pid);
 		trace_seq_printf(s, " %5d:%3d:%c %s [%03d] %5d:%3d:%c %s\n",
 				 field->prev_pid,
@@ -1448,6 +1926,27 @@ print_lat_fmt(struct trace_iterator *iter, unsigned int trace_idx, int cpu)
 			trace_seq_print_cont(s, iter);
 		break;
 	}
+	case TRACE_BRANCH: {
+		struct trace_branch *field;
+
+		trace_assign_type(field, entry);
+
+		trace_seq_printf(s, "[%s] %s:%s:%d\n",
+				 field->correct ? "  ok  " : " MISS ",
+				 field->func,
+				 field->file,
+				 field->line);
+		break;
+	}
+	case TRACE_USER_STACK: {
+		struct userstack_entry *field;
+
+		trace_assign_type(field, entry);
+
+		seq_print_userip_objs(field, s, sym_flags);
+		trace_seq_putc(s, '\n');
+		break;
+	}
 	default:
 		trace_seq_printf(s, "Unknown type %d\n", entry->type);
 	}
@@ -1472,6 +1971,8 @@ static enum print_line_t print_trace_fmt(struct trace_iterator *iter)
 	if (entry->type == TRACE_CONT)
 		return TRACE_TYPE_HANDLED;
 
+	test_cpu_buff_start(iter);
+
 	comm = trace_find_cmdline(iter->ent->pid);
 
 	t = ns2usecs(iter->ts);
@@ -1519,10 +2020,8 @@ static enum print_line_t print_trace_fmt(struct trace_iterator *iter)
 
 		trace_assign_type(field, entry);
 
-		S = field->prev_state < sizeof(state_to_char) ?
-			state_to_char[field->prev_state] : 'X';
-		T = field->next_state < sizeof(state_to_char) ?
-			state_to_char[field->next_state] : 'X';
+		T = task_state_char(field->next_state);
+		S = task_state_char(field->prev_state);
 		ret = trace_seq_printf(s, " %5d:%3d:%c %s [%03d] %5d:%3d:%c\n",
 				       field->prev_pid,
 				       field->prev_prio,
@@ -1581,6 +2080,37 @@ static enum print_line_t print_trace_fmt(struct trace_iterator *iter)
 			trace_seq_print_cont(s, iter);
 		break;
 	}
+	case TRACE_GRAPH_RET: {
+		return print_graph_function(iter);
+	}
+	case TRACE_GRAPH_ENT: {
+		return print_graph_function(iter);
+	}
+	case TRACE_BRANCH: {
+		struct trace_branch *field;
+
+		trace_assign_type(field, entry);
+
+		trace_seq_printf(s, "[%s] %s:%s:%d\n",
+				 field->correct ? "  ok  " : " MISS ",
+				 field->func,
+				 field->file,
+				 field->line);
+		break;
+	}
+	case TRACE_USER_STACK: {
+		struct userstack_entry *field;
+
+		trace_assign_type(field, entry);
+
+		ret = seq_print_userip_objs(field, s, sym_flags);
+		if (!ret)
+			return TRACE_TYPE_PARTIAL_LINE;
+		ret = trace_seq_putc(s, '\n');
+		if (!ret)
+			return TRACE_TYPE_PARTIAL_LINE;
+		break;
+	}
 	}
 	return TRACE_TYPE_HANDLED;
 }
@@ -1621,12 +2151,9 @@ static enum print_line_t print_raw_fmt(struct trace_iterator *iter)
 
 		trace_assign_type(field, entry);
 
-		S = field->prev_state < sizeof(state_to_char) ?
-			state_to_char[field->prev_state] : 'X';
-		T = field->next_state < sizeof(state_to_char) ?
-			state_to_char[field->next_state] : 'X';
-		if (entry->type == TRACE_WAKE)
-			S = '+';
+		T = task_state_char(field->next_state);
+		S = entry->type == TRACE_WAKE ? '+' :
+			task_state_char(field->prev_state);
 		ret = trace_seq_printf(s, "%d %d %c %d %d %d %c\n",
 				       field->prev_pid,
 				       field->prev_prio,
@@ -1640,6 +2167,7 @@ static enum print_line_t print_raw_fmt(struct trace_iterator *iter)
 		break;
 	}
 	case TRACE_SPECIAL:
+	case TRACE_USER_STACK:
 	case TRACE_STACK: {
 		struct special_entry *field;
 
@@ -1712,12 +2240,9 @@ static enum print_line_t print_hex_fmt(struct trace_iterator *iter)
 
 		trace_assign_type(field, entry);
 
-		S = field->prev_state < sizeof(state_to_char) ?
-			state_to_char[field->prev_state] : 'X';
-		T = field->next_state < sizeof(state_to_char) ?
-			state_to_char[field->next_state] : 'X';
-		if (entry->type == TRACE_WAKE)
-			S = '+';
+		T = task_state_char(field->next_state);
+		S = entry->type == TRACE_WAKE ? '+' :
+			task_state_char(field->prev_state);
 		SEQ_PUT_HEX_FIELD_RET(s, field->prev_pid);
 		SEQ_PUT_HEX_FIELD_RET(s, field->prev_prio);
 		SEQ_PUT_HEX_FIELD_RET(s, S);
@@ -1728,6 +2253,7 @@ static enum print_line_t print_hex_fmt(struct trace_iterator *iter)
 		break;
 	}
 	case TRACE_SPECIAL:
+	case TRACE_USER_STACK:
 	case TRACE_STACK: {
 		struct special_entry *field;
 
@@ -1744,6 +2270,25 @@ static enum print_line_t print_hex_fmt(struct trace_iterator *iter)
 	return TRACE_TYPE_HANDLED;
 }
 
+static enum print_line_t print_printk_msg_only(struct trace_iterator *iter)
+{
+	struct trace_seq *s = &iter->seq;
+	struct trace_entry *entry = iter->ent;
+	struct print_entry *field;
+	int ret;
+
+	trace_assign_type(field, entry);
+
+	ret = trace_seq_printf(s, field->buf);
+	if (!ret)
+		return TRACE_TYPE_PARTIAL_LINE;
+
+	if (entry->flags & TRACE_FLAG_CONT)
+		trace_seq_print_cont(s, iter);
+
+	return TRACE_TYPE_HANDLED;
+}
+
 static enum print_line_t print_bin_fmt(struct trace_iterator *iter)
 {
 	struct trace_seq *s = &iter->seq;
@@ -1782,6 +2327,7 @@ static enum print_line_t print_bin_fmt(struct trace_iterator *iter)
 		break;
 	}
 	case TRACE_SPECIAL:
+	case TRACE_USER_STACK:
 	case TRACE_STACK: {
 		struct special_entry *field;
 
@@ -1823,6 +2369,11 @@ static enum print_line_t print_trace_line(struct trace_iterator *iter)
 			return ret;
 	}
 
+	if (iter->ent->type == TRACE_PRINT &&
+			trace_flags & TRACE_ITER_PRINTK &&
+			trace_flags & TRACE_ITER_PRINTK_MSGONLY)
+		return print_printk_msg_only(iter);
+
 	if (trace_flags & TRACE_ITER_BIN)
 		return print_bin_fmt(iter);
 
@@ -1847,7 +2398,9 @@ static int s_show(struct seq_file *m, void *v)
 			seq_printf(m, "# tracer: %s\n", iter->trace->name);
 			seq_puts(m, "#\n");
 		}
-		if (iter->iter_flags & TRACE_FILE_LAT_FMT) {
+		if (iter->trace && iter->trace->print_header)
+			iter->trace->print_header(m);
+		else if (iter->iter_flags & TRACE_FILE_LAT_FMT) {
 			/* print nothing if the buffers are empty */
 			if (trace_empty(iter))
 				return 0;
@@ -1899,6 +2452,15 @@ __tracing_open(struct inode *inode, struct file *file, int *ret)
 	iter->trace = current_trace;
 	iter->pos = -1;
 
+	/* Notify the tracer early; before we stop tracing. */
+	if (iter->trace && iter->trace->open)
+		iter->trace->open(iter);
+
+	/* Annotate start of buffers if we had overruns */
+	if (ring_buffer_overruns(iter->tr->buffer))
+		iter->iter_flags |= TRACE_FILE_ANNOTATE;
+
+
 	for_each_tracing_cpu(cpu) {
 
 		iter->buffer_iter[cpu] =
@@ -1917,13 +2479,7 @@ __tracing_open(struct inode *inode, struct file *file, int *ret)
 	m->private = iter;
 
 	/* stop the trace while dumping */
-	if (iter->tr->ctrl) {
-		tracer_enabled = 0;
-		ftrace_function_enabled = 0;
-	}
-
-	if (iter->trace && iter->trace->open)
-			iter->trace->open(iter);
+	tracing_stop();
 
 	mutex_unlock(&trace_types_lock);
 
@@ -1966,14 +2522,7 @@ int tracing_release(struct inode *inode, struct file *file)
 		iter->trace->close(iter);
 
 	/* reenable tracing if it was previously enabled */
-	if (iter->tr->ctrl) {
-		tracer_enabled = 1;
-		/*
-		 * It is safe to enable function tracing even if it
-		 * isn't used
-		 */
-		ftrace_function_enabled = 1;
-	}
+	tracing_start();
 	mutex_unlock(&trace_types_lock);
 
 	seq_release(inode, file);
@@ -2151,7 +2700,7 @@ tracing_cpumask_write(struct file *filp, const char __user *ubuf,
 	if (err)
 		goto err_unlock;
 
-	raw_local_irq_disable();
+	local_irq_disable();
 	__raw_spin_lock(&ftrace_max_lock);
 	for_each_tracing_cpu(cpu) {
 		/*
@@ -2168,7 +2717,7 @@ tracing_cpumask_write(struct file *filp, const char __user *ubuf,
 		}
 	}
 	__raw_spin_unlock(&ftrace_max_lock);
-	raw_local_irq_enable();
+	local_irq_enable();
 
 	tracing_cpumask = tracing_cpumask_new;
 
@@ -2189,13 +2738,16 @@ static struct file_operations tracing_cpumask_fops = {
 };
 
 static ssize_t
-tracing_iter_ctrl_read(struct file *filp, char __user *ubuf,
+tracing_trace_options_read(struct file *filp, char __user *ubuf,
 		       size_t cnt, loff_t *ppos)
 {
+	int i;
 	char *buf;
 	int r = 0;
 	int len = 0;
-	int i;
+	u32 tracer_flags = current_trace->flags->val;
+	struct tracer_opt *trace_opts = current_trace->flags->opts;
+
 
 	/* calulate max size */
 	for (i = 0; trace_options[i]; i++) {
@@ -2203,6 +2755,15 @@ tracing_iter_ctrl_read(struct file *filp, char __user *ubuf,
 		len += 3; /* "no" and space */
 	}
 
+	/*
+	 * Increase the size with names of options specific
+	 * of the current tracer.
+	 */
+	for (i = 0; trace_opts[i].name; i++) {
+		len += strlen(trace_opts[i].name);
+		len += 3; /* "no" and space */
+	}
+
 	/* +2 for \n and \0 */
 	buf = kmalloc(len + 2, GFP_KERNEL);
 	if (!buf)
@@ -2215,6 +2776,15 @@ tracing_iter_ctrl_read(struct file *filp, char __user *ubuf,
 			r += sprintf(buf + r, "no%s ", trace_options[i]);
 	}
 
+	for (i = 0; trace_opts[i].name; i++) {
+		if (tracer_flags & trace_opts[i].bit)
+			r += sprintf(buf + r, "%s ",
+				trace_opts[i].name);
+		else
+			r += sprintf(buf + r, "no%s ",
+				trace_opts[i].name);
+	}
+
 	r += sprintf(buf + r, "\n");
 	WARN_ON(r >= len + 2);
 
@@ -2225,13 +2795,48 @@ tracing_iter_ctrl_read(struct file *filp, char __user *ubuf,
 	return r;
 }
 
+/* Try to assign a tracer specific option */
+static int set_tracer_option(struct tracer *trace, char *cmp, int neg)
+{
+	struct tracer_flags *trace_flags = trace->flags;
+	struct tracer_opt *opts = NULL;
+	int ret = 0, i = 0;
+	int len;
+
+	for (i = 0; trace_flags->opts[i].name; i++) {
+		opts = &trace_flags->opts[i];
+		len = strlen(opts->name);
+
+		if (strncmp(cmp, opts->name, len) == 0) {
+			ret = trace->set_flag(trace_flags->val,
+				opts->bit, !neg);
+			break;
+		}
+	}
+	/* Not found */
+	if (!trace_flags->opts[i].name)
+		return -EINVAL;
+
+	/* Refused to handle */
+	if (ret)
+		return ret;
+
+	if (neg)
+		trace_flags->val &= ~opts->bit;
+	else
+		trace_flags->val |= opts->bit;
+
+	return 0;
+}
+
 static ssize_t
-tracing_iter_ctrl_write(struct file *filp, const char __user *ubuf,
+tracing_trace_options_write(struct file *filp, const char __user *ubuf,
 			size_t cnt, loff_t *ppos)
 {
 	char buf[64];
 	char *cmp = buf;
 	int neg = 0;
+	int ret;
 	int i;
 
 	if (cnt >= sizeof(buf))
@@ -2258,11 +2863,13 @@ tracing_iter_ctrl_write(struct file *filp, const char __user *ubuf,
 			break;
 		}
 	}
-	/*
-	 * If no option could be set, return an error:
-	 */
-	if (!trace_options[i])
-		return -EINVAL;
+
+	/* If no option could be set, test the specific tracer options */
+	if (!trace_options[i]) {
+		ret = set_tracer_option(current_trace, cmp, neg);
+		if (ret)
+			return ret;
+	}
 
 	filp->f_pos += cnt;
 
@@ -2271,8 +2878,8 @@ tracing_iter_ctrl_write(struct file *filp, const char __user *ubuf,
 
 static struct file_operations tracing_iter_fops = {
 	.open		= tracing_open_generic,
-	.read		= tracing_iter_ctrl_read,
-	.write		= tracing_iter_ctrl_write,
+	.read		= tracing_trace_options_read,
+	.write		= tracing_trace_options_write,
 };
 
 static const char readme_msg[] =
@@ -2286,9 +2893,9 @@ static const char readme_msg[] =
 	"# echo sched_switch > /debug/tracing/current_tracer\n"
 	"# cat /debug/tracing/current_tracer\n"
 	"sched_switch\n"
-	"# cat /debug/tracing/iter_ctrl\n"
+	"# cat /debug/tracing/trace_options\n"
 	"noprint-parent nosym-offset nosym-addr noverbose\n"
-	"# echo print-parent > /debug/tracing/iter_ctrl\n"
+	"# echo print-parent > /debug/tracing/trace_options\n"
 	"# echo 1 > /debug/tracing/tracing_enabled\n"
 	"# cat /debug/tracing/trace > /tmp/trace.txt\n"
 	"echo 0 > /debug/tracing/tracing_enabled\n"
@@ -2311,11 +2918,10 @@ static ssize_t
 tracing_ctrl_read(struct file *filp, char __user *ubuf,
 		  size_t cnt, loff_t *ppos)
 {
-	struct trace_array *tr = filp->private_data;
 	char buf[64];
 	int r;
 
-	r = sprintf(buf, "%ld\n", tr->ctrl);
+	r = sprintf(buf, "%u\n", tracer_enabled);
 	return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
 }
 
@@ -2343,16 +2949,18 @@ tracing_ctrl_write(struct file *filp, const char __user *ubuf,
 	val = !!val;
 
 	mutex_lock(&trace_types_lock);
-	if (tr->ctrl ^ val) {
-		if (val)
+	if (tracer_enabled ^ val) {
+		if (val) {
 			tracer_enabled = 1;
-		else
+			if (current_trace->start)
+				current_trace->start(tr);
+			tracing_start();
+		} else {
 			tracer_enabled = 0;
-
-		tr->ctrl = val;
-
-		if (current_trace && current_trace->ctrl_update)
-			current_trace->ctrl_update(tr);
+			tracing_stop();
+			if (current_trace->stop)
+				current_trace->stop(tr);
+		}
 	}
 	mutex_unlock(&trace_types_lock);
 
@@ -2378,29 +2986,11 @@ tracing_set_trace_read(struct file *filp, char __user *ubuf,
 	return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
 }
 
-static ssize_t
-tracing_set_trace_write(struct file *filp, const char __user *ubuf,
-			size_t cnt, loff_t *ppos)
+static int tracing_set_tracer(char *buf)
 {
 	struct trace_array *tr = &global_trace;
 	struct tracer *t;
-	char buf[max_tracer_type_len+1];
-	int i;
-	size_t ret;
-
-	ret = cnt;
-
-	if (cnt > max_tracer_type_len)
-		cnt = max_tracer_type_len;
-
-	if (copy_from_user(&buf, ubuf, cnt))
-		return -EFAULT;
-
-	buf[cnt] = 0;
-
-	/* strip ending whitespace. */
-	for (i = cnt - 1; i > 0 && isspace(buf[i]); i--)
-		buf[i] = 0;
+	int ret = 0;
 
 	mutex_lock(&trace_types_lock);
 	for (t = trace_types; t; t = t->next) {
@@ -2414,18 +3004,52 @@ tracing_set_trace_write(struct file *filp, const char __user *ubuf,
 	if (t == current_trace)
 		goto out;
 
+	trace_branch_disable();
 	if (current_trace && current_trace->reset)
 		current_trace->reset(tr);
 
 	current_trace = t;
-	if (t->init)
-		t->init(tr);
+	if (t->init) {
+		ret = t->init(tr);
+		if (ret)
+			goto out;
+	}
 
+	trace_branch_enable(tr);
  out:
 	mutex_unlock(&trace_types_lock);
 
-	if (ret > 0)
-		filp->f_pos += ret;
+	return ret;
+}
+
+static ssize_t
+tracing_set_trace_write(struct file *filp, const char __user *ubuf,
+			size_t cnt, loff_t *ppos)
+{
+	char buf[max_tracer_type_len+1];
+	int i;
+	size_t ret;
+	int err;
+
+	ret = cnt;
+
+	if (cnt > max_tracer_type_len)
+		cnt = max_tracer_type_len;
+
+	if (copy_from_user(&buf, ubuf, cnt))
+		return -EFAULT;
+
+	buf[cnt] = 0;
+
+	/* strip ending whitespace. */
+	for (i = cnt - 1; i > 0 && isspace(buf[i]); i--)
+		buf[i] = 0;
+
+	err = tracing_set_tracer(buf);
+	if (err)
+		return err;
+
+	filp->f_pos += ret;
 
 	return ret;
 }
@@ -2492,6 +3116,10 @@ static int tracing_open_pipe(struct inode *inode, struct file *filp)
 		return -ENOMEM;
 
 	mutex_lock(&trace_types_lock);
+
+	/* trace pipe does not show start of buffer */
+	cpus_setall(iter->started);
+
 	iter->tr = &global_trace;
 	iter->trace = current_trace;
 	filp->private_data = iter;
@@ -2667,7 +3295,7 @@ tracing_entries_read(struct file *filp, char __user *ubuf,
 	char buf[64];
 	int r;
 
-	r = sprintf(buf, "%lu\n", tr->entries);
+	r = sprintf(buf, "%lu\n", tr->entries >> 10);
 	return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
 }
 
@@ -2678,7 +3306,6 @@ tracing_entries_write(struct file *filp, const char __user *ubuf,
 	unsigned long val;
 	char buf[64];
 	int ret, cpu;
-	struct trace_array *tr = filp->private_data;
 
 	if (cnt >= sizeof(buf))
 		return -EINVAL;
@@ -2698,12 +3325,7 @@ tracing_entries_write(struct file *filp, const char __user *ubuf,
 
 	mutex_lock(&trace_types_lock);
 
-	if (tr->ctrl) {
-		cnt = -EBUSY;
-		pr_info("ftrace: please disable tracing"
-			" before modifying buffer size\n");
-		goto out;
-	}
+	tracing_stop();
 
 	/* disable all cpu buffers */
 	for_each_tracing_cpu(cpu) {
@@ -2713,6 +3335,9 @@ tracing_entries_write(struct file *filp, const char __user *ubuf,
 			atomic_inc(&max_tr.data[cpu]->disabled);
 	}
 
+	/* value is in KB */
+	val <<= 10;
+
 	if (val != global_trace.entries) {
 		ret = ring_buffer_resize(global_trace.buffer, val);
 		if (ret < 0) {
@@ -2751,6 +3376,7 @@ tracing_entries_write(struct file *filp, const char __user *ubuf,
 			atomic_dec(&max_tr.data[cpu]->disabled);
 	}
 
+	tracing_start();
 	max_tr.entries = global_trace.entries;
 	mutex_unlock(&trace_types_lock);
 
@@ -2762,7 +3388,7 @@ static int mark_printk(const char *fmt, ...)
 	int ret;
 	va_list args;
 	va_start(args, fmt);
-	ret = trace_vprintk(0, fmt, args);
+	ret = trace_vprintk(0, -1, fmt, args);
 	va_end(args);
 	return ret;
 }
@@ -2773,9 +3399,8 @@ tracing_mark_write(struct file *filp, const char __user *ubuf,
 {
 	char *buf;
 	char *end;
-	struct trace_array *tr = &global_trace;
 
-	if (!tr->ctrl || tracing_disabled)
+	if (tracing_disabled)
 		return -EINVAL;
 
 	if (cnt > TRACE_BUF_SIZE)
@@ -2841,22 +3466,38 @@ static struct file_operations tracing_mark_fops = {
 
 #ifdef CONFIG_DYNAMIC_FTRACE
 
+int __weak ftrace_arch_read_dyn_info(char *buf, int size)
+{
+	return 0;
+}
+
 static ssize_t
-tracing_read_long(struct file *filp, char __user *ubuf,
+tracing_read_dyn_info(struct file *filp, char __user *ubuf,
 		  size_t cnt, loff_t *ppos)
 {
+	static char ftrace_dyn_info_buffer[1024];
+	static DEFINE_MUTEX(dyn_info_mutex);
 	unsigned long *p = filp->private_data;
-	char buf[64];
+	char *buf = ftrace_dyn_info_buffer;
+	int size = ARRAY_SIZE(ftrace_dyn_info_buffer);
 	int r;
 
-	r = sprintf(buf, "%ld\n", *p);
+	mutex_lock(&dyn_info_mutex);
+	r = sprintf(buf, "%ld ", *p);
 
-	return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
+	r += ftrace_arch_read_dyn_info(buf+r, (size-1)-r);
+	buf[r++] = '\n';
+
+	r = simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
+
+	mutex_unlock(&dyn_info_mutex);
+
+	return r;
 }
 
-static struct file_operations tracing_read_long_fops = {
+static struct file_operations tracing_dyn_info_fops = {
 	.open		= tracing_open_generic,
-	.read		= tracing_read_long,
+	.read		= tracing_read_dyn_info,
 };
 #endif
 
@@ -2897,10 +3538,10 @@ static __init int tracer_init_debugfs(void)
 	if (!entry)
 		pr_warning("Could not create debugfs 'tracing_enabled' entry\n");
 
-	entry = debugfs_create_file("iter_ctrl", 0644, d_tracer,
+	entry = debugfs_create_file("trace_options", 0644, d_tracer,
 				    NULL, &tracing_iter_fops);
 	if (!entry)
-		pr_warning("Could not create debugfs 'iter_ctrl' entry\n");
+		pr_warning("Could not create debugfs 'trace_options' entry\n");
 
 	entry = debugfs_create_file("tracing_cpumask", 0644, d_tracer,
 				    NULL, &tracing_cpumask_fops);
@@ -2950,11 +3591,11 @@ static __init int tracer_init_debugfs(void)
 		pr_warning("Could not create debugfs "
 			   "'trace_pipe' entry\n");
 
-	entry = debugfs_create_file("trace_entries", 0644, d_tracer,
+	entry = debugfs_create_file("buffer_size_kb", 0644, d_tracer,
 				    &global_trace, &tracing_entries_fops);
 	if (!entry)
 		pr_warning("Could not create debugfs "
-			   "'trace_entries' entry\n");
+			   "'buffer_size_kb' entry\n");
 
 	entry = debugfs_create_file("trace_marker", 0220, d_tracer,
 				    NULL, &tracing_mark_fops);
@@ -2965,7 +3606,7 @@ static __init int tracer_init_debugfs(void)
 #ifdef CONFIG_DYNAMIC_FTRACE
 	entry = debugfs_create_file("dyn_ftrace_total_info", 0444, d_tracer,
 				    &ftrace_update_tot_cnt,
-				    &tracing_read_long_fops);
+				    &tracing_dyn_info_fops);
 	if (!entry)
 		pr_warning("Could not create debugfs "
 			   "'dyn_ftrace_total_info' entry\n");
@@ -2976,7 +3617,7 @@ static __init int tracer_init_debugfs(void)
 	return 0;
 }
 
-int trace_vprintk(unsigned long ip, const char *fmt, va_list args)
+int trace_vprintk(unsigned long ip, int depth, const char *fmt, va_list args)
 {
 	static DEFINE_SPINLOCK(trace_buf_lock);
 	static char trace_buf[TRACE_BUF_SIZE];
@@ -2984,11 +3625,11 @@ int trace_vprintk(unsigned long ip, const char *fmt, va_list args)
 	struct ring_buffer_event *event;
 	struct trace_array *tr = &global_trace;
 	struct trace_array_cpu *data;
-	struct print_entry *entry;
-	unsigned long flags, irq_flags;
 	int cpu, len = 0, size, pc;
+	struct print_entry *entry;
+	unsigned long irq_flags;
 
-	if (!tr->ctrl || tracing_disabled)
+	if (tracing_disabled || tracing_selftest_running)
 		return 0;
 
 	pc = preempt_count();
@@ -2999,7 +3640,8 @@ int trace_vprintk(unsigned long ip, const char *fmt, va_list args)
 	if (unlikely(atomic_read(&data->disabled)))
 		goto out;
 
-	spin_lock_irqsave(&trace_buf_lock, flags);
+	pause_graph_tracing();
+	spin_lock_irqsave(&trace_buf_lock, irq_flags);
 	len = vsnprintf(trace_buf, TRACE_BUF_SIZE, fmt, args);
 
 	len = min(len, TRACE_BUF_SIZE-1);
@@ -3010,17 +3652,18 @@ int trace_vprintk(unsigned long ip, const char *fmt, va_list args)
 	if (!event)
 		goto out_unlock;
 	entry = ring_buffer_event_data(event);
-	tracing_generic_entry_update(&entry->ent, flags, pc);
+	tracing_generic_entry_update(&entry->ent, irq_flags, pc);
 	entry->ent.type			= TRACE_PRINT;
 	entry->ip			= ip;
+	entry->depth			= depth;
 
 	memcpy(&entry->buf, trace_buf, len);
 	entry->buf[len] = 0;
 	ring_buffer_unlock_commit(tr->buffer, event, irq_flags);
 
  out_unlock:
-	spin_unlock_irqrestore(&trace_buf_lock, flags);
-
+	spin_unlock_irqrestore(&trace_buf_lock, irq_flags);
+	unpause_graph_tracing();
  out:
 	preempt_enable_notrace();
 
@@ -3037,7 +3680,7 @@ int __ftrace_printk(unsigned long ip, const char *fmt, ...)
 		return 0;
 
 	va_start(ap, fmt);
-	ret = trace_vprintk(ip, fmt, ap);
+	ret = trace_vprintk(ip, task_curr_ret_stack(current), fmt, ap);
 	va_end(ap);
 	return ret;
 }
@@ -3046,7 +3689,8 @@ EXPORT_SYMBOL_GPL(__ftrace_printk);
 static int trace_panic_handler(struct notifier_block *this,
 			       unsigned long event, void *unused)
 {
-	ftrace_dump();
+	if (ftrace_dump_on_oops)
+		ftrace_dump();
 	return NOTIFY_OK;
 }
 
@@ -3062,7 +3706,8 @@ static int trace_die_handler(struct notifier_block *self,
 {
 	switch (val) {
 	case DIE_OOPS:
-		ftrace_dump();
+		if (ftrace_dump_on_oops)
+			ftrace_dump();
 		break;
 	default:
 		break;
@@ -3103,7 +3748,6 @@ trace_printk_seq(struct trace_seq *s)
 	trace_seq_reset(s);
 }
 
-
 void ftrace_dump(void)
 {
 	static DEFINE_SPINLOCK(ftrace_dump_lock);
@@ -3128,6 +3772,9 @@ void ftrace_dump(void)
 		atomic_inc(&global_trace.data[cpu]->disabled);
 	}
 
+	/* don't look at user memory in panic mode */
+	trace_flags &= ~TRACE_ITER_SYM_USEROBJ;
+
 	printk(KERN_TRACE "Dumping ftrace buffer:\n");
 
 	iter.tr = &global_trace;
@@ -3221,7 +3868,6 @@ __init static int tracer_alloc_buffers(void)
 #endif
 
 	/* All seems OK, enable tracing */
-	global_trace.ctrl = tracer_enabled;
 	tracing_disabled = 0;
 
 	atomic_notifier_chain_register(&panic_notifier_list,
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 8465ad0..cc7a4f8 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -8,6 +8,7 @@
 #include <linux/ring_buffer.h>
 #include <linux/mmiotrace.h>
 #include <linux/ftrace.h>
+#include <trace/boot.h>
 
 enum trace_type {
 	__TRACE_FIRST_TYPE = 0,
@@ -21,7 +22,14 @@ enum trace_type {
 	TRACE_SPECIAL,
 	TRACE_MMIO_RW,
 	TRACE_MMIO_MAP,
-	TRACE_BOOT,
+	TRACE_BRANCH,
+	TRACE_BOOT_CALL,
+	TRACE_BOOT_RET,
+	TRACE_GRAPH_RET,
+	TRACE_GRAPH_ENT,
+	TRACE_USER_STACK,
+	TRACE_HW_BRANCHES,
+	TRACE_POWER,
 
 	__TRACE_LAST_TYPE
 };
@@ -38,6 +46,7 @@ struct trace_entry {
 	unsigned char		flags;
 	unsigned char		preempt_count;
 	int			pid;
+	int			tgid;
 };
 
 /*
@@ -48,6 +57,18 @@ struct ftrace_entry {
 	unsigned long		ip;
 	unsigned long		parent_ip;
 };
+
+/* Function call entry */
+struct ftrace_graph_ent_entry {
+	struct trace_entry			ent;
+	struct ftrace_graph_ent		graph_ent;
+};
+
+/* Function return entry */
+struct ftrace_graph_ret_entry {
+	struct trace_entry			ent;
+	struct ftrace_graph_ret		ret;
+};
 extern struct tracer boot_tracer;
 
 /*
@@ -85,12 +106,18 @@ struct stack_entry {
 	unsigned long		caller[FTRACE_STACK_ENTRIES];
 };
 
+struct userstack_entry {
+	struct trace_entry	ent;
+	unsigned long		caller[FTRACE_STACK_ENTRIES];
+};
+
 /*
  * ftrace_printk entry:
  */
 struct print_entry {
 	struct trace_entry	ent;
 	unsigned long		ip;
+	int			depth;
 	char			buf[];
 };
 
@@ -112,9 +139,35 @@ struct trace_mmiotrace_map {
 	struct mmiotrace_map	map;
 };
 
-struct trace_boot {
+struct trace_boot_call {
 	struct trace_entry	ent;
-	struct boot_trace	initcall;
+	struct boot_trace_call boot_call;
+};
+
+struct trace_boot_ret {
+	struct trace_entry	ent;
+	struct boot_trace_ret boot_ret;
+};
+
+#define TRACE_FUNC_SIZE 30
+#define TRACE_FILE_SIZE 20
+struct trace_branch {
+	struct trace_entry	ent;
+	unsigned	        line;
+	char			func[TRACE_FUNC_SIZE+1];
+	char			file[TRACE_FILE_SIZE+1];
+	char			correct;
+};
+
+struct hw_branch_entry {
+	struct trace_entry	ent;
+	u64			from;
+	u64			to;
+};
+
+struct trace_power {
+	struct trace_entry	ent;
+	struct power_trace	state_data;
 };
 
 /*
@@ -172,7 +225,6 @@ struct trace_iterator;
 struct trace_array {
 	struct ring_buffer	*buffer;
 	unsigned long		entries;
-	long			ctrl;
 	int			cpu;
 	cycle_t			time_start;
 	struct task_struct	*waiter;
@@ -212,13 +264,22 @@ extern void __ftrace_bad_type(void);
 		IF_ASSIGN(var, ent, struct ctx_switch_entry, 0);	\
 		IF_ASSIGN(var, ent, struct trace_field_cont, TRACE_CONT); \
 		IF_ASSIGN(var, ent, struct stack_entry, TRACE_STACK);	\
+		IF_ASSIGN(var, ent, struct userstack_entry, TRACE_USER_STACK);\
 		IF_ASSIGN(var, ent, struct print_entry, TRACE_PRINT);	\
 		IF_ASSIGN(var, ent, struct special_entry, 0);		\
 		IF_ASSIGN(var, ent, struct trace_mmiotrace_rw,		\
 			  TRACE_MMIO_RW);				\
 		IF_ASSIGN(var, ent, struct trace_mmiotrace_map,		\
 			  TRACE_MMIO_MAP);				\
-		IF_ASSIGN(var, ent, struct trace_boot, TRACE_BOOT);	\
+		IF_ASSIGN(var, ent, struct trace_boot_call, TRACE_BOOT_CALL);\
+		IF_ASSIGN(var, ent, struct trace_boot_ret, TRACE_BOOT_RET);\
+		IF_ASSIGN(var, ent, struct trace_branch, TRACE_BRANCH); \
+		IF_ASSIGN(var, ent, struct ftrace_graph_ent_entry,	\
+			  TRACE_GRAPH_ENT);		\
+		IF_ASSIGN(var, ent, struct ftrace_graph_ret_entry,	\
+			  TRACE_GRAPH_RET);		\
+		IF_ASSIGN(var, ent, struct hw_branch_entry, TRACE_HW_BRANCHES);\
+ 		IF_ASSIGN(var, ent, struct trace_power, TRACE_POWER); \
 		__ftrace_bad_type();					\
 	} while (0)
 
@@ -229,29 +290,56 @@ enum print_line_t {
 	TRACE_TYPE_UNHANDLED	= 2	/* Relay to other output functions */
 };
 
+
+/*
+ * An option specific to a tracer. This is a boolean value.
+ * The bit is the bit index that sets its value on the
+ * flags value in struct tracer_flags.
+ */
+struct tracer_opt {
+	const char 	*name; /* Will appear on the trace_options file */
+	u32 		bit; /* Mask assigned in val field in tracer_flags */
+};
+
+/*
+ * The set of specific options for a tracer. Your tracer
+ * have to set the initial value of the flags val.
+ */
+struct tracer_flags {
+	u32			val;
+	struct tracer_opt 	*opts;
+};
+
+/* Makes more easy to define a tracer opt */
+#define TRACER_OPT(s, b)	.name = #s, .bit = b
+
 /*
  * A specific tracer, represented by methods that operate on a trace array:
  */
 struct tracer {
 	const char		*name;
-	void			(*init)(struct trace_array *tr);
+	/* Your tracer should raise a warning if init fails */
+	int			(*init)(struct trace_array *tr);
 	void			(*reset)(struct trace_array *tr);
+	void			(*start)(struct trace_array *tr);
+	void			(*stop)(struct trace_array *tr);
 	void			(*open)(struct trace_iterator *iter);
 	void			(*pipe_open)(struct trace_iterator *iter);
 	void			(*close)(struct trace_iterator *iter);
-	void			(*start)(struct trace_iterator *iter);
-	void			(*stop)(struct trace_iterator *iter);
 	ssize_t			(*read)(struct trace_iterator *iter,
 					struct file *filp, char __user *ubuf,
 					size_t cnt, loff_t *ppos);
-	void			(*ctrl_update)(struct trace_array *tr);
 #ifdef CONFIG_FTRACE_STARTUP_TEST
 	int			(*selftest)(struct tracer *trace,
 					    struct trace_array *tr);
 #endif
+	void			(*print_header)(struct seq_file *m);
 	enum print_line_t	(*print_line)(struct trace_iterator *iter);
+	/* If you handled the flag setting, return 0 */
+	int			(*set_flag)(u32 old_flags, u32 bit, int set);
 	struct tracer		*next;
 	int			print_max;
+	struct tracer_flags 	*flags;
 };
 
 struct trace_seq {
@@ -279,10 +367,14 @@ struct trace_iterator {
 	unsigned long		iter_flags;
 	loff_t			pos;
 	long			idx;
+
+	cpumask_t		started;
 };
 
+int tracing_is_enabled(void);
 void trace_wake_up(void);
 void tracing_reset(struct trace_array *tr, int cpu);
+void tracing_reset_online_cpus(struct trace_array *tr);
 int tracing_open_generic(struct inode *inode, struct file *filp);
 struct dentry *tracing_init_dentry(void);
 void init_tracer_sysprof_debugfs(struct dentry *d_tracer);
@@ -321,8 +413,15 @@ void trace_function(struct trace_array *tr,
 		    unsigned long parent_ip,
 		    unsigned long flags, int pc);
 
+void trace_graph_return(struct ftrace_graph_ret *trace);
+int trace_graph_entry(struct ftrace_graph_ent *trace);
+void trace_hw_branch(struct trace_array *tr, u64 from, u64 to);
+
 void tracing_start_cmdline_record(void);
 void tracing_stop_cmdline_record(void);
+void tracing_sched_switch_assign_trace(struct trace_array *tr);
+void tracing_stop_sched_switch_record(void);
+void tracing_start_sched_switch_record(void);
 int register_tracer(struct tracer *type);
 void unregister_tracer(struct tracer *type);
 
@@ -358,6 +457,7 @@ struct tracer_switch_ops {
 	struct tracer_switch_ops	*next;
 };
 
+char *trace_find_cmdline(int pid);
 #endif /* CONFIG_CONTEXT_SWITCH_TRACER */
 
 #ifdef CONFIG_DYNAMIC_FTRACE
@@ -383,19 +483,79 @@ extern int trace_selftest_startup_sched_switch(struct tracer *trace,
 					       struct trace_array *tr);
 extern int trace_selftest_startup_sysprof(struct tracer *trace,
 					       struct trace_array *tr);
+extern int trace_selftest_startup_branch(struct tracer *trace,
+					 struct trace_array *tr);
 #endif /* CONFIG_FTRACE_STARTUP_TEST */
 
 extern void *head_page(struct trace_array_cpu *data);
 extern int trace_seq_printf(struct trace_seq *s, const char *fmt, ...);
 extern void trace_seq_print_cont(struct trace_seq *s,
 				 struct trace_iterator *iter);
+
+extern int
+seq_print_ip_sym(struct trace_seq *s, unsigned long ip,
+		unsigned long sym_flags);
 extern ssize_t trace_seq_to_user(struct trace_seq *s, char __user *ubuf,
 				 size_t cnt);
 extern long ns2usecs(cycle_t nsec);
-extern int trace_vprintk(unsigned long ip, const char *fmt, va_list args);
+extern int
+trace_vprintk(unsigned long ip, int depth, const char *fmt, va_list args);
 
 extern unsigned long trace_flags;
 
+/* Standard output formatting function used for function return traces */
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+extern enum print_line_t print_graph_function(struct trace_iterator *iter);
+
+#ifdef CONFIG_DYNAMIC_FTRACE
+/* TODO: make this variable */
+#define FTRACE_GRAPH_MAX_FUNCS		32
+extern int ftrace_graph_count;
+extern unsigned long ftrace_graph_funcs[FTRACE_GRAPH_MAX_FUNCS];
+
+static inline int ftrace_graph_addr(unsigned long addr)
+{
+	int i;
+
+	if (!ftrace_graph_count || test_tsk_trace_graph(current))
+		return 1;
+
+	for (i = 0; i < ftrace_graph_count; i++) {
+		if (addr == ftrace_graph_funcs[i])
+			return 1;
+	}
+
+	return 0;
+}
+#else
+static inline int ftrace_trace_addr(unsigned long addr)
+{
+	return 1;
+}
+static inline int ftrace_graph_addr(unsigned long addr)
+{
+	return 1;
+}
+#endif /* CONFIG_DYNAMIC_FTRACE */
+
+#else /* CONFIG_FUNCTION_GRAPH_TRACER */
+static inline enum print_line_t
+print_graph_function(struct trace_iterator *iter)
+{
+	return TRACE_TYPE_UNHANDLED;
+}
+#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
+
+extern struct pid *ftrace_pid_trace;
+
+static inline int ftrace_trace_task(struct task_struct *task)
+{
+	if (!ftrace_pid_trace)
+		return 1;
+
+	return test_tsk_trace_trace(task);
+}
+
 /*
  * trace_iterator_flags is an enumeration that defines bit
  * positions into trace_flags that controls the output.
@@ -415,8 +575,93 @@ enum trace_iterator_flags {
 	TRACE_ITER_STACKTRACE		= 0x100,
 	TRACE_ITER_SCHED_TREE		= 0x200,
 	TRACE_ITER_PRINTK		= 0x400,
+	TRACE_ITER_PREEMPTONLY		= 0x800,
+	TRACE_ITER_BRANCH		= 0x1000,
+	TRACE_ITER_ANNOTATE		= 0x2000,
+	TRACE_ITER_USERSTACKTRACE       = 0x4000,
+	TRACE_ITER_SYM_USEROBJ          = 0x8000,
+	TRACE_ITER_PRINTK_MSGONLY	= 0x10000
 };
 
+/*
+ * TRACE_ITER_SYM_MASK masks the options in trace_flags that
+ * control the output of kernel symbols.
+ */
+#define TRACE_ITER_SYM_MASK \
+	(TRACE_ITER_PRINT_PARENT|TRACE_ITER_SYM_OFFSET|TRACE_ITER_SYM_ADDR)
+
 extern struct tracer nop_trace;
 
+/**
+ * ftrace_preempt_disable - disable preemption scheduler safe
+ *
+ * When tracing can happen inside the scheduler, there exists
+ * cases that the tracing might happen before the need_resched
+ * flag is checked. If this happens and the tracer calls
+ * preempt_enable (after a disable), a schedule might take place
+ * causing an infinite recursion.
+ *
+ * To prevent this, we read the need_recshed flag before
+ * disabling preemption. When we want to enable preemption we
+ * check the flag, if it is set, then we call preempt_enable_no_resched.
+ * Otherwise, we call preempt_enable.
+ *
+ * The rational for doing the above is that if need resched is set
+ * and we have yet to reschedule, we are either in an atomic location
+ * (where we do not need to check for scheduling) or we are inside
+ * the scheduler and do not want to resched.
+ */
+static inline int ftrace_preempt_disable(void)
+{
+	int resched;
+
+	resched = need_resched();
+	preempt_disable_notrace();
+
+	return resched;
+}
+
+/**
+ * ftrace_preempt_enable - enable preemption scheduler safe
+ * @resched: the return value from ftrace_preempt_disable
+ *
+ * This is a scheduler safe way to enable preemption and not miss
+ * any preemption checks. The disabled saved the state of preemption.
+ * If resched is set, then we were either inside an atomic or
+ * are inside the scheduler (we would have already scheduled
+ * otherwise). In this case, we do not want to call normal
+ * preempt_enable, but preempt_enable_no_resched instead.
+ */
+static inline void ftrace_preempt_enable(int resched)
+{
+	if (resched)
+		preempt_enable_no_resched_notrace();
+	else
+		preempt_enable_notrace();
+}
+
+#ifdef CONFIG_BRANCH_TRACER
+extern int enable_branch_tracing(struct trace_array *tr);
+extern void disable_branch_tracing(void);
+static inline int trace_branch_enable(struct trace_array *tr)
+{
+	if (trace_flags & TRACE_ITER_BRANCH)
+		return enable_branch_tracing(tr);
+	return 0;
+}
+static inline void trace_branch_disable(void)
+{
+	/* due to races, always disable */
+	disable_branch_tracing();
+}
+#else
+static inline int trace_branch_enable(struct trace_array *tr)
+{
+	return 0;
+}
+static inline void trace_branch_disable(void)
+{
+}
+#endif /* CONFIG_BRANCH_TRACER */
+
 #endif /* _LINUX_KERNEL_TRACE_H */
diff --git a/kernel/trace/trace_boot.c b/kernel/trace/trace_boot.c
index d0a5e50..3ccebde 100644
--- a/kernel/trace/trace_boot.c
+++ b/kernel/trace/trace_boot.c
@@ -13,101 +13,161 @@
 #include "trace.h"
 
 static struct trace_array *boot_trace;
-static int trace_boot_enabled;
+static bool pre_initcalls_finished;
 
-
-/* Should be started after do_pre_smp_initcalls() in init/main.c */
+/* Tells the boot tracer that the pre_smp_initcalls are finished.
+ * So we are ready .
+ * It doesn't enable sched events tracing however.
+ * You have to call enable_boot_trace to do so.
+ */
 void start_boot_trace(void)
 {
-	trace_boot_enabled = 1;
+	pre_initcalls_finished = true;
 }
 
-void stop_boot_trace(void)
+void enable_boot_trace(void)
 {
-	trace_boot_enabled = 0;
+	if (pre_initcalls_finished)
+		tracing_start_sched_switch_record();
 }
 
-void reset_boot_trace(struct trace_array *tr)
+void disable_boot_trace(void)
 {
-	stop_boot_trace();
+	if (pre_initcalls_finished)
+		tracing_stop_sched_switch_record();
 }
 
-static void boot_trace_init(struct trace_array *tr)
+static int boot_trace_init(struct trace_array *tr)
 {
 	int cpu;
 	boot_trace = tr;
 
-	trace_boot_enabled = 0;
-
 	for_each_cpu_mask(cpu, cpu_possible_map)
 		tracing_reset(tr, cpu);
+
+	tracing_sched_switch_assign_trace(tr);
+	return 0;
 }
 
-static void boot_trace_ctrl_update(struct trace_array *tr)
+static enum print_line_t
+initcall_call_print_line(struct trace_iterator *iter)
 {
-	if (tr->ctrl)
-		start_boot_trace();
+	struct trace_entry *entry = iter->ent;
+	struct trace_seq *s = &iter->seq;
+	struct trace_boot_call *field;
+	struct boot_trace_call *call;
+	u64 ts;
+	unsigned long nsec_rem;
+	int ret;
+
+	trace_assign_type(field, entry);
+	call = &field->boot_call;
+	ts = iter->ts;
+	nsec_rem = do_div(ts, 1000000000);
+
+	ret = trace_seq_printf(s, "[%5ld.%09ld] calling  %s @ %i\n",
+			(unsigned long)ts, nsec_rem, call->func, call->caller);
+
+	if (!ret)
+		return TRACE_TYPE_PARTIAL_LINE;
 	else
-		stop_boot_trace();
+		return TRACE_TYPE_HANDLED;
 }
 
-static enum print_line_t initcall_print_line(struct trace_iterator *iter)
+static enum print_line_t
+initcall_ret_print_line(struct trace_iterator *iter)
 {
-	int ret;
 	struct trace_entry *entry = iter->ent;
-	struct trace_boot *field = (struct trace_boot *)entry;
-	struct boot_trace *it = &field->initcall;
 	struct trace_seq *s = &iter->seq;
-	struct timespec calltime = ktime_to_timespec(it->calltime);
-	struct timespec rettime = ktime_to_timespec(it->rettime);
-
-	if (entry->type == TRACE_BOOT) {
-		ret = trace_seq_printf(s, "[%5ld.%09ld] calling  %s @ %i\n",
-					  calltime.tv_sec,
-					  calltime.tv_nsec,
-					  it->func, it->caller);
-		if (!ret)
-			return TRACE_TYPE_PARTIAL_LINE;
-
-		ret = trace_seq_printf(s, "[%5ld.%09ld] initcall %s "
-					  "returned %d after %lld msecs\n",
-					  rettime.tv_sec,
-					  rettime.tv_nsec,
-					  it->func, it->result, it->duration);
-
-		if (!ret)
-			return TRACE_TYPE_PARTIAL_LINE;
+	struct trace_boot_ret *field;
+	struct boot_trace_ret *init_ret;
+	u64 ts;
+	unsigned long nsec_rem;
+	int ret;
+
+	trace_assign_type(field, entry);
+	init_ret = &field->boot_ret;
+	ts = iter->ts;
+	nsec_rem = do_div(ts, 1000000000);
+
+	ret = trace_seq_printf(s, "[%5ld.%09ld] initcall %s "
+			"returned %d after %llu msecs\n",
+			(unsigned long) ts,
+			nsec_rem,
+			init_ret->func, init_ret->result, init_ret->duration);
+
+	if (!ret)
+		return TRACE_TYPE_PARTIAL_LINE;
+	else
 		return TRACE_TYPE_HANDLED;
+}
+
+static enum print_line_t initcall_print_line(struct trace_iterator *iter)
+{
+	struct trace_entry *entry = iter->ent;
+
+	switch (entry->type) {
+	case TRACE_BOOT_CALL:
+		return initcall_call_print_line(iter);
+	case TRACE_BOOT_RET:
+		return initcall_ret_print_line(iter);
+	default:
+		return TRACE_TYPE_UNHANDLED;
 	}
-	return TRACE_TYPE_UNHANDLED;
 }
 
 struct tracer boot_tracer __read_mostly =
 {
 	.name		= "initcall",
 	.init		= boot_trace_init,
-	.reset		= reset_boot_trace,
-	.ctrl_update	= boot_trace_ctrl_update,
+	.reset		= tracing_reset_online_cpus,
 	.print_line	= initcall_print_line,
 };
 
-void trace_boot(struct boot_trace *it, initcall_t fn)
+void trace_boot_call(struct boot_trace_call *bt, initcall_t fn)
 {
 	struct ring_buffer_event *event;
-	struct trace_boot *entry;
-	struct trace_array_cpu *data;
+	struct trace_boot_call *entry;
 	unsigned long irq_flags;
 	struct trace_array *tr = boot_trace;
 
-	if (!trace_boot_enabled)
+	if (!pre_initcalls_finished)
 		return;
 
 	/* Get its name now since this function could
 	 * disappear because it is in the .init section.
 	 */
-	sprint_symbol(it->func, (unsigned long)fn);
+	sprint_symbol(bt->func, (unsigned long)fn);
+	preempt_disable();
+
+	event = ring_buffer_lock_reserve(tr->buffer, sizeof(*entry),
+					 &irq_flags);
+	if (!event)
+		goto out;
+	entry	= ring_buffer_event_data(event);
+	tracing_generic_entry_update(&entry->ent, 0, 0);
+	entry->ent.type = TRACE_BOOT_CALL;
+	entry->boot_call = *bt;
+	ring_buffer_unlock_commit(tr->buffer, event, irq_flags);
+
+	trace_wake_up();
+
+ out:
+	preempt_enable();
+}
+
+void trace_boot_ret(struct boot_trace_ret *bt, initcall_t fn)
+{
+	struct ring_buffer_event *event;
+	struct trace_boot_ret *entry;
+	unsigned long irq_flags;
+	struct trace_array *tr = boot_trace;
+
+	if (!pre_initcalls_finished)
+		return;
+
+	sprint_symbol(bt->func, (unsigned long)fn);
 	preempt_disable();
-	data = tr->data[smp_processor_id()];
 
 	event = ring_buffer_lock_reserve(tr->buffer, sizeof(*entry),
 					 &irq_flags);
@@ -115,8 +175,8 @@ void trace_boot(struct boot_trace *it, initcall_t fn)
 		goto out;
 	entry	= ring_buffer_event_data(event);
 	tracing_generic_entry_update(&entry->ent, 0, 0);
-	entry->ent.type = TRACE_BOOT;
-	entry->initcall = *it;
+	entry->ent.type = TRACE_BOOT_RET;
+	entry->boot_ret = *bt;
 	ring_buffer_unlock_commit(tr->buffer, event, irq_flags);
 
 	trace_wake_up();
diff --git a/kernel/trace/trace_branch.c b/kernel/trace/trace_branch.c
new file mode 100644
index 0000000..6c00feb
--- /dev/null
+++ b/kernel/trace/trace_branch.c
@@ -0,0 +1,342 @@
+/*
+ * unlikely profiler
+ *
+ * Copyright (C) 2008 Steven Rostedt <srostedt@redhat.com>
+ */
+#include <linux/kallsyms.h>
+#include <linux/seq_file.h>
+#include <linux/spinlock.h>
+#include <linux/irqflags.h>
+#include <linux/debugfs.h>
+#include <linux/uaccess.h>
+#include <linux/module.h>
+#include <linux/ftrace.h>
+#include <linux/hash.h>
+#include <linux/fs.h>
+#include <asm/local.h>
+#include "trace.h"
+
+#ifdef CONFIG_BRANCH_TRACER
+
+static int branch_tracing_enabled __read_mostly;
+static DEFINE_MUTEX(branch_tracing_mutex);
+static struct trace_array *branch_tracer;
+
+static void
+probe_likely_condition(struct ftrace_branch_data *f, int val, int expect)
+{
+	struct trace_array *tr = branch_tracer;
+	struct ring_buffer_event *event;
+	struct trace_branch *entry;
+	unsigned long flags, irq_flags;
+	int cpu, pc;
+	const char *p;
+
+	/*
+	 * I would love to save just the ftrace_likely_data pointer, but
+	 * this code can also be used by modules. Ugly things can happen
+	 * if the module is unloaded, and then we go and read the
+	 * pointer.  This is slower, but much safer.
+	 */
+
+	if (unlikely(!tr))
+		return;
+
+	local_irq_save(flags);
+	cpu = raw_smp_processor_id();
+	if (atomic_inc_return(&tr->data[cpu]->disabled) != 1)
+		goto out;
+
+	event = ring_buffer_lock_reserve(tr->buffer, sizeof(*entry),
+					 &irq_flags);
+	if (!event)
+		goto out;
+
+	pc = preempt_count();
+	entry	= ring_buffer_event_data(event);
+	tracing_generic_entry_update(&entry->ent, flags, pc);
+	entry->ent.type		= TRACE_BRANCH;
+
+	/* Strip off the path, only save the file */
+	p = f->file + strlen(f->file);
+	while (p >= f->file && *p != '/')
+		p--;
+	p++;
+
+	strncpy(entry->func, f->func, TRACE_FUNC_SIZE);
+	strncpy(entry->file, p, TRACE_FILE_SIZE);
+	entry->func[TRACE_FUNC_SIZE] = 0;
+	entry->file[TRACE_FILE_SIZE] = 0;
+	entry->line = f->line;
+	entry->correct = val == expect;
+
+	ring_buffer_unlock_commit(tr->buffer, event, irq_flags);
+
+ out:
+	atomic_dec(&tr->data[cpu]->disabled);
+	local_irq_restore(flags);
+}
+
+static inline
+void trace_likely_condition(struct ftrace_branch_data *f, int val, int expect)
+{
+	if (!branch_tracing_enabled)
+		return;
+
+	probe_likely_condition(f, val, expect);
+}
+
+int enable_branch_tracing(struct trace_array *tr)
+{
+	int ret = 0;
+
+	mutex_lock(&branch_tracing_mutex);
+	branch_tracer = tr;
+	/*
+	 * Must be seen before enabling. The reader is a condition
+	 * where we do not need a matching rmb()
+	 */
+	smp_wmb();
+	branch_tracing_enabled++;
+	mutex_unlock(&branch_tracing_mutex);
+
+	return ret;
+}
+
+void disable_branch_tracing(void)
+{
+	mutex_lock(&branch_tracing_mutex);
+
+	if (!branch_tracing_enabled)
+		goto out_unlock;
+
+	branch_tracing_enabled--;
+
+ out_unlock:
+	mutex_unlock(&branch_tracing_mutex);
+}
+
+static void start_branch_trace(struct trace_array *tr)
+{
+	enable_branch_tracing(tr);
+}
+
+static void stop_branch_trace(struct trace_array *tr)
+{
+	disable_branch_tracing();
+}
+
+static int branch_trace_init(struct trace_array *tr)
+{
+	int cpu;
+
+	for_each_online_cpu(cpu)
+		tracing_reset(tr, cpu);
+
+	start_branch_trace(tr);
+	return 0;
+}
+
+static void branch_trace_reset(struct trace_array *tr)
+{
+	stop_branch_trace(tr);
+}
+
+struct tracer branch_trace __read_mostly =
+{
+	.name		= "branch",
+	.init		= branch_trace_init,
+	.reset		= branch_trace_reset,
+#ifdef CONFIG_FTRACE_SELFTEST
+	.selftest	= trace_selftest_startup_branch,
+#endif
+};
+
+__init static int init_branch_trace(void)
+{
+	return register_tracer(&branch_trace);
+}
+
+device_initcall(init_branch_trace);
+#else
+static inline
+void trace_likely_condition(struct ftrace_branch_data *f, int val, int expect)
+{
+}
+#endif /* CONFIG_BRANCH_TRACER */
+
+void ftrace_likely_update(struct ftrace_branch_data *f, int val, int expect)
+{
+	/*
+	 * I would love to have a trace point here instead, but the
+	 * trace point code is so inundated with unlikely and likely
+	 * conditions that the recursive nightmare that exists is too
+	 * much to try to get working. At least for now.
+	 */
+	trace_likely_condition(f, val, expect);
+
+	/* FIXME: Make this atomic! */
+	if (val == expect)
+		f->correct++;
+	else
+		f->incorrect++;
+}
+EXPORT_SYMBOL(ftrace_likely_update);
+
+struct ftrace_pointer {
+	void		*start;
+	void		*stop;
+	int		hit;
+};
+
+static void *
+t_next(struct seq_file *m, void *v, loff_t *pos)
+{
+	const struct ftrace_pointer *f = m->private;
+	struct ftrace_branch_data *p = v;
+
+	(*pos)++;
+
+	if (v == (void *)1)
+		return f->start;
+
+	++p;
+
+	if ((void *)p >= (void *)f->stop)
+		return NULL;
+
+	return p;
+}
+
+static void *t_start(struct seq_file *m, loff_t *pos)
+{
+	void *t = (void *)1;
+	loff_t l = 0;
+
+	for (; t && l < *pos; t = t_next(m, t, &l))
+		;
+
+	return t;
+}
+
+static void t_stop(struct seq_file *m, void *p)
+{
+}
+
+static int t_show(struct seq_file *m, void *v)
+{
+	const struct ftrace_pointer *fp = m->private;
+	struct ftrace_branch_data *p = v;
+	const char *f;
+	long percent;
+
+	if (v == (void *)1) {
+		if (fp->hit)
+			seq_printf(m, "   miss      hit    %% ");
+		else
+			seq_printf(m, " correct incorrect  %% ");
+		seq_printf(m, "       Function                "
+			      "  File              Line\n"
+			      " ------- ---------  - "
+			      "       --------                "
+			      "  ----              ----\n");
+		return 0;
+	}
+
+	/* Only print the file, not the path */
+	f = p->file + strlen(p->file);
+	while (f >= p->file && *f != '/')
+		f--;
+	f++;
+
+	/*
+	 * The miss is overlayed on correct, and hit on incorrect.
+	 */
+	if (p->correct) {
+		percent = p->incorrect * 100;
+		percent /= p->correct + p->incorrect;
+	} else
+		percent = p->incorrect ? 100 : -1;
+
+	seq_printf(m, "%8lu %8lu ",  p->correct, p->incorrect);
+	if (percent < 0)
+		seq_printf(m, "  X ");
+	else
+		seq_printf(m, "%3ld ", percent);
+	seq_printf(m, "%-30.30s %-20.20s %d\n", p->func, f, p->line);
+	return 0;
+}
+
+static struct seq_operations tracing_likely_seq_ops = {
+	.start		= t_start,
+	.next		= t_next,
+	.stop		= t_stop,
+	.show		= t_show,
+};
+
+static int tracing_branch_open(struct inode *inode, struct file *file)
+{
+	int ret;
+
+	ret = seq_open(file, &tracing_likely_seq_ops);
+	if (!ret) {
+		struct seq_file *m = file->private_data;
+		m->private = (void *)inode->i_private;
+	}
+
+	return ret;
+}
+
+static const struct file_operations tracing_branch_fops = {
+	.open		= tracing_branch_open,
+	.read		= seq_read,
+	.llseek		= seq_lseek,
+};
+
+#ifdef CONFIG_PROFILE_ALL_BRANCHES
+extern unsigned long __start_branch_profile[];
+extern unsigned long __stop_branch_profile[];
+
+static const struct ftrace_pointer ftrace_branch_pos = {
+	.start			= __start_branch_profile,
+	.stop			= __stop_branch_profile,
+	.hit			= 1,
+};
+
+#endif /* CONFIG_PROFILE_ALL_BRANCHES */
+
+extern unsigned long __start_annotated_branch_profile[];
+extern unsigned long __stop_annotated_branch_profile[];
+
+static const struct ftrace_pointer ftrace_annotated_branch_pos = {
+	.start			= __start_annotated_branch_profile,
+	.stop			= __stop_annotated_branch_profile,
+};
+
+static __init int ftrace_branch_init(void)
+{
+	struct dentry *d_tracer;
+	struct dentry *entry;
+
+	d_tracer = tracing_init_dentry();
+
+	entry = debugfs_create_file("profile_annotated_branch", 0444, d_tracer,
+				    (void *)&ftrace_annotated_branch_pos,
+				    &tracing_branch_fops);
+	if (!entry)
+		pr_warning("Could not create debugfs "
+			   "'profile_annotatet_branch' entry\n");
+
+#ifdef CONFIG_PROFILE_ALL_BRANCHES
+	entry = debugfs_create_file("profile_branch", 0444, d_tracer,
+				    (void *)&ftrace_branch_pos,
+				    &tracing_branch_fops);
+	if (!entry)
+		pr_warning("Could not create debugfs"
+			   " 'profile_branch' entry\n");
+#endif
+
+	return 0;
+}
+
+device_initcall(ftrace_branch_init);
diff --git a/kernel/trace/trace_functions.c b/kernel/trace/trace_functions.c
index 0f85a64..9236d7e 100644
--- a/kernel/trace/trace_functions.c
+++ b/kernel/trace/trace_functions.c
@@ -16,20 +16,10 @@
 
 #include "trace.h"
 
-static void function_reset(struct trace_array *tr)
-{
-	int cpu;
-
-	tr->time_start = ftrace_now(tr->cpu);
-
-	for_each_online_cpu(cpu)
-		tracing_reset(tr, cpu);
-}
-
 static void start_function_trace(struct trace_array *tr)
 {
 	tr->cpu = get_cpu();
-	function_reset(tr);
+	tracing_reset_online_cpus(tr);
 	put_cpu();
 
 	tracing_start_cmdline_record();
@@ -42,24 +32,20 @@ static void stop_function_trace(struct trace_array *tr)
 	tracing_stop_cmdline_record();
 }
 
-static void function_trace_init(struct trace_array *tr)
+static int function_trace_init(struct trace_array *tr)
 {
-	if (tr->ctrl)
-		start_function_trace(tr);
+	start_function_trace(tr);
+	return 0;
 }
 
 static void function_trace_reset(struct trace_array *tr)
 {
-	if (tr->ctrl)
-		stop_function_trace(tr);
+	stop_function_trace(tr);
 }
 
-static void function_trace_ctrl_update(struct trace_array *tr)
+static void function_trace_start(struct trace_array *tr)
 {
-	if (tr->ctrl)
-		start_function_trace(tr);
-	else
-		stop_function_trace(tr);
+	tracing_reset_online_cpus(tr);
 }
 
 static struct tracer function_trace __read_mostly =
@@ -67,7 +53,7 @@ static struct tracer function_trace __read_mostly =
 	.name	     = "function",
 	.init	     = function_trace_init,
 	.reset	     = function_trace_reset,
-	.ctrl_update = function_trace_ctrl_update,
+	.start	     = function_trace_start,
 #ifdef CONFIG_FTRACE_SELFTEST
 	.selftest    = trace_selftest_startup_function,
 #endif
diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c
new file mode 100644
index 0000000..4bf39fc
--- /dev/null
+++ b/kernel/trace/trace_functions_graph.c
@@ -0,0 +1,669 @@
+/*
+ *
+ * Function graph tracer.
+ * Copyright (c) 2008 Frederic Weisbecker <fweisbec@gmail.com>
+ * Mostly borrowed from function tracer which
+ * is Copyright (c) Steven Rostedt <srostedt@redhat.com>
+ *
+ */
+#include <linux/debugfs.h>
+#include <linux/uaccess.h>
+#include <linux/ftrace.h>
+#include <linux/fs.h>
+
+#include "trace.h"
+
+#define TRACE_GRAPH_INDENT	2
+
+/* Flag options */
+#define TRACE_GRAPH_PRINT_OVERRUN	0x1
+#define TRACE_GRAPH_PRINT_CPU		0x2
+#define TRACE_GRAPH_PRINT_OVERHEAD	0x4
+#define TRACE_GRAPH_PRINT_PROC		0x8
+
+static struct tracer_opt trace_opts[] = {
+	/* Display overruns ? */
+	{ TRACER_OPT(funcgraph-overrun, TRACE_GRAPH_PRINT_OVERRUN) },
+	/* Display CPU ? */
+	{ TRACER_OPT(funcgraph-cpu, TRACE_GRAPH_PRINT_CPU) },
+	/* Display Overhead ? */
+	{ TRACER_OPT(funcgraph-overhead, TRACE_GRAPH_PRINT_OVERHEAD) },
+	/* Display proc name/pid */
+	{ TRACER_OPT(funcgraph-proc, TRACE_GRAPH_PRINT_PROC) },
+	{ } /* Empty entry */
+};
+
+static struct tracer_flags tracer_flags = {
+	/* Don't display overruns and proc by default */
+	.val = TRACE_GRAPH_PRINT_CPU | TRACE_GRAPH_PRINT_OVERHEAD,
+	.opts = trace_opts
+};
+
+/* pid on the last trace processed */
+static pid_t last_pid[NR_CPUS] = { [0 ... NR_CPUS-1] = -1 };
+
+static int graph_trace_init(struct trace_array *tr)
+{
+	int cpu, ret;
+
+	for_each_online_cpu(cpu)
+		tracing_reset(tr, cpu);
+
+	ret = register_ftrace_graph(&trace_graph_return,
+					&trace_graph_entry);
+	if (ret)
+		return ret;
+	tracing_start_cmdline_record();
+
+	return 0;
+}
+
+static void graph_trace_reset(struct trace_array *tr)
+{
+	tracing_stop_cmdline_record();
+	unregister_ftrace_graph();
+}
+
+static inline int log10_cpu(int nb)
+{
+	if (nb / 100)
+		return 3;
+	if (nb / 10)
+		return 2;
+	return 1;
+}
+
+static enum print_line_t
+print_graph_cpu(struct trace_seq *s, int cpu)
+{
+	int i;
+	int ret;
+	int log10_this = log10_cpu(cpu);
+	int log10_all = log10_cpu(cpus_weight_nr(cpu_online_map));
+
+
+	/*
+	 * Start with a space character - to make it stand out
+	 * to the right a bit when trace output is pasted into
+	 * email:
+	 */
+	ret = trace_seq_printf(s, " ");
+
+	/*
+	 * Tricky - we space the CPU field according to the max
+	 * number of online CPUs. On a 2-cpu system it would take
+	 * a maximum of 1 digit - on a 128 cpu system it would
+	 * take up to 3 digits:
+	 */
+	for (i = 0; i < log10_all - log10_this; i++) {
+		ret = trace_seq_printf(s, " ");
+		if (!ret)
+			return TRACE_TYPE_PARTIAL_LINE;
+	}
+	ret = trace_seq_printf(s, "%d) ", cpu);
+	if (!ret)
+		return TRACE_TYPE_PARTIAL_LINE;
+
+	return TRACE_TYPE_HANDLED;
+}
+
+#define TRACE_GRAPH_PROCINFO_LENGTH	14
+
+static enum print_line_t
+print_graph_proc(struct trace_seq *s, pid_t pid)
+{
+	int i;
+	int ret;
+	int len;
+	char comm[8];
+	int spaces = 0;
+	/* sign + log10(MAX_INT) + '\0' */
+	char pid_str[11];
+
+	strncpy(comm, trace_find_cmdline(pid), 7);
+	comm[7] = '\0';
+	sprintf(pid_str, "%d", pid);
+
+	/* 1 stands for the "-" character */
+	len = strlen(comm) + strlen(pid_str) + 1;
+
+	if (len < TRACE_GRAPH_PROCINFO_LENGTH)
+		spaces = TRACE_GRAPH_PROCINFO_LENGTH - len;
+
+	/* First spaces to align center */
+	for (i = 0; i < spaces / 2; i++) {
+		ret = trace_seq_printf(s, " ");
+		if (!ret)
+			return TRACE_TYPE_PARTIAL_LINE;
+	}
+
+	ret = trace_seq_printf(s, "%s-%s", comm, pid_str);
+	if (!ret)
+		return TRACE_TYPE_PARTIAL_LINE;
+
+	/* Last spaces to align center */
+	for (i = 0; i < spaces - (spaces / 2); i++) {
+		ret = trace_seq_printf(s, " ");
+		if (!ret)
+			return TRACE_TYPE_PARTIAL_LINE;
+	}
+	return TRACE_TYPE_HANDLED;
+}
+
+
+/* If the pid changed since the last trace, output this event */
+static enum print_line_t
+verif_pid(struct trace_seq *s, pid_t pid, int cpu)
+{
+	pid_t prev_pid;
+	int ret;
+
+	if (last_pid[cpu] != -1 && last_pid[cpu] == pid)
+		return TRACE_TYPE_HANDLED;
+
+	prev_pid = last_pid[cpu];
+	last_pid[cpu] = pid;
+
+/*
+ * Context-switch trace line:
+
+ ------------------------------------------
+ | 1)  migration/0--1  =>  sshd-1755
+ ------------------------------------------
+
+ */
+	ret = trace_seq_printf(s,
+		" ------------------------------------------\n");
+	if (!ret)
+		TRACE_TYPE_PARTIAL_LINE;
+
+	ret = print_graph_cpu(s, cpu);
+	if (ret == TRACE_TYPE_PARTIAL_LINE)
+		TRACE_TYPE_PARTIAL_LINE;
+
+	ret = print_graph_proc(s, prev_pid);
+	if (ret == TRACE_TYPE_PARTIAL_LINE)
+		TRACE_TYPE_PARTIAL_LINE;
+
+	ret = trace_seq_printf(s, " => ");
+	if (!ret)
+		TRACE_TYPE_PARTIAL_LINE;
+
+	ret = print_graph_proc(s, pid);
+	if (ret == TRACE_TYPE_PARTIAL_LINE)
+		TRACE_TYPE_PARTIAL_LINE;
+
+	ret = trace_seq_printf(s,
+		"\n ------------------------------------------\n\n");
+	if (!ret)
+		TRACE_TYPE_PARTIAL_LINE;
+
+	return ret;
+}
+
+static bool
+trace_branch_is_leaf(struct trace_iterator *iter,
+		struct ftrace_graph_ent_entry *curr)
+{
+	struct ring_buffer_iter *ring_iter;
+	struct ring_buffer_event *event;
+	struct ftrace_graph_ret_entry *next;
+
+	ring_iter = iter->buffer_iter[iter->cpu];
+
+	if (!ring_iter)
+		return false;
+
+	event = ring_buffer_iter_peek(ring_iter, NULL);
+
+	if (!event)
+		return false;
+
+	next = ring_buffer_event_data(event);
+
+	if (next->ent.type != TRACE_GRAPH_RET)
+		return false;
+
+	if (curr->ent.pid != next->ent.pid ||
+			curr->graph_ent.func != next->ret.func)
+		return false;
+
+	return true;
+}
+
+static enum print_line_t
+print_graph_irq(struct trace_seq *s, unsigned long addr,
+				enum trace_type type, int cpu, pid_t pid)
+{
+	int ret;
+
+	if (addr < (unsigned long)__irqentry_text_start ||
+		addr >= (unsigned long)__irqentry_text_end)
+		return TRACE_TYPE_UNHANDLED;
+
+	if (type == TRACE_GRAPH_ENT) {
+		ret = trace_seq_printf(s, "==========> |  ");
+	} else {
+		/* Cpu */
+		if (tracer_flags.val & TRACE_GRAPH_PRINT_CPU) {
+			ret = print_graph_cpu(s, cpu);
+			if (ret == TRACE_TYPE_PARTIAL_LINE)
+				return TRACE_TYPE_PARTIAL_LINE;
+		}
+		/* Proc */
+		if (tracer_flags.val & TRACE_GRAPH_PRINT_PROC) {
+			ret = print_graph_proc(s, pid);
+			if (ret == TRACE_TYPE_PARTIAL_LINE)
+				return TRACE_TYPE_PARTIAL_LINE;
+
+			ret = trace_seq_printf(s, " | ");
+			if (!ret)
+				return TRACE_TYPE_PARTIAL_LINE;
+		}
+
+		/* No overhead */
+		if (tracer_flags.val & TRACE_GRAPH_PRINT_OVERHEAD) {
+			ret = trace_seq_printf(s, "  ");
+			if (!ret)
+				return TRACE_TYPE_PARTIAL_LINE;
+		}
+
+		ret = trace_seq_printf(s, "<========== |\n");
+	}
+	if (!ret)
+		return TRACE_TYPE_PARTIAL_LINE;
+	return TRACE_TYPE_HANDLED;
+}
+
+static enum print_line_t
+print_graph_duration(unsigned long long duration, struct trace_seq *s)
+{
+	unsigned long nsecs_rem = do_div(duration, 1000);
+	/* log10(ULONG_MAX) + '\0' */
+	char msecs_str[21];
+	char nsecs_str[5];
+	int ret, len;
+	int i;
+
+	sprintf(msecs_str, "%lu", (unsigned long) duration);
+
+	/* Print msecs */
+	ret = trace_seq_printf(s, msecs_str);
+	if (!ret)
+		return TRACE_TYPE_PARTIAL_LINE;
+
+	len = strlen(msecs_str);
+
+	/* Print nsecs (we don't want to exceed 7 numbers) */
+	if (len < 7) {
+		snprintf(nsecs_str, 8 - len, "%03lu", nsecs_rem);
+		ret = trace_seq_printf(s, ".%s", nsecs_str);
+		if (!ret)
+			return TRACE_TYPE_PARTIAL_LINE;
+		len += strlen(nsecs_str);
+	}
+
+	ret = trace_seq_printf(s, " us ");
+	if (!ret)
+		return TRACE_TYPE_PARTIAL_LINE;
+
+	/* Print remaining spaces to fit the row's width */
+	for (i = len; i < 7; i++) {
+		ret = trace_seq_printf(s, " ");
+		if (!ret)
+			return TRACE_TYPE_PARTIAL_LINE;
+	}
+
+	ret = trace_seq_printf(s, "|  ");
+	if (!ret)
+		return TRACE_TYPE_PARTIAL_LINE;
+	return TRACE_TYPE_HANDLED;
+
+}
+
+/* Signal a overhead of time execution to the output */
+static int
+print_graph_overhead(unsigned long long duration, struct trace_seq *s)
+{
+	/* Duration exceeded 100 msecs */
+	if (duration > 100000ULL)
+		return trace_seq_printf(s, "! ");
+
+	/* Duration exceeded 10 msecs */
+	if (duration > 10000ULL)
+		return trace_seq_printf(s, "+ ");
+
+	return trace_seq_printf(s, "  ");
+}
+
+/* Case of a leaf function on its call entry */
+static enum print_line_t
+print_graph_entry_leaf(struct trace_iterator *iter,
+		struct ftrace_graph_ent_entry *entry, struct trace_seq *s)
+{
+	struct ftrace_graph_ret_entry *ret_entry;
+	struct ftrace_graph_ret *graph_ret;
+	struct ring_buffer_event *event;
+	struct ftrace_graph_ent *call;
+	unsigned long long duration;
+	int ret;
+	int i;
+
+	event = ring_buffer_read(iter->buffer_iter[iter->cpu], NULL);
+	ret_entry = ring_buffer_event_data(event);
+	graph_ret = &ret_entry->ret;
+	call = &entry->graph_ent;
+	duration = graph_ret->rettime - graph_ret->calltime;
+
+	/* Overhead */
+	if (tracer_flags.val & TRACE_GRAPH_PRINT_OVERHEAD) {
+		ret = print_graph_overhead(duration, s);
+		if (!ret)
+			return TRACE_TYPE_PARTIAL_LINE;
+	}
+
+	/* Duration */
+	ret = print_graph_duration(duration, s);
+	if (ret == TRACE_TYPE_PARTIAL_LINE)
+		return TRACE_TYPE_PARTIAL_LINE;
+
+	/* Function */
+	for (i = 0; i < call->depth * TRACE_GRAPH_INDENT; i++) {
+		ret = trace_seq_printf(s, " ");
+		if (!ret)
+			return TRACE_TYPE_PARTIAL_LINE;
+	}
+
+	ret = seq_print_ip_sym(s, call->func, 0);
+	if (!ret)
+		return TRACE_TYPE_PARTIAL_LINE;
+
+	ret = trace_seq_printf(s, "();\n");
+	if (!ret)
+		return TRACE_TYPE_PARTIAL_LINE;
+
+	return TRACE_TYPE_HANDLED;
+}
+
+static enum print_line_t
+print_graph_entry_nested(struct ftrace_graph_ent_entry *entry,
+			struct trace_seq *s, pid_t pid, int cpu)
+{
+	int i;
+	int ret;
+	struct ftrace_graph_ent *call = &entry->graph_ent;
+
+	/* No overhead */
+	if (tracer_flags.val & TRACE_GRAPH_PRINT_OVERHEAD) {
+		ret = trace_seq_printf(s, "  ");
+		if (!ret)
+			return TRACE_TYPE_PARTIAL_LINE;
+	}
+
+	/* Interrupt */
+	ret = print_graph_irq(s, call->func, TRACE_GRAPH_ENT, cpu, pid);
+	if (ret == TRACE_TYPE_UNHANDLED) {
+		/* No time */
+		ret = trace_seq_printf(s, "            |  ");
+		if (!ret)
+			return TRACE_TYPE_PARTIAL_LINE;
+	} else {
+		if (ret == TRACE_TYPE_PARTIAL_LINE)
+			return TRACE_TYPE_PARTIAL_LINE;
+	}
+
+
+	/* Function */
+	for (i = 0; i < call->depth * TRACE_GRAPH_INDENT; i++) {
+		ret = trace_seq_printf(s, " ");
+		if (!ret)
+			return TRACE_TYPE_PARTIAL_LINE;
+	}
+
+	ret = seq_print_ip_sym(s, call->func, 0);
+	if (!ret)
+		return TRACE_TYPE_PARTIAL_LINE;
+
+	ret = trace_seq_printf(s, "() {\n");
+	if (!ret)
+		return TRACE_TYPE_PARTIAL_LINE;
+
+	return TRACE_TYPE_HANDLED;
+}
+
+static enum print_line_t
+print_graph_entry(struct ftrace_graph_ent_entry *field, struct trace_seq *s,
+			struct trace_iterator *iter, int cpu)
+{
+	int ret;
+	struct trace_entry *ent = iter->ent;
+
+	/* Pid */
+	if (verif_pid(s, ent->pid, cpu) == TRACE_TYPE_PARTIAL_LINE)
+		return TRACE_TYPE_PARTIAL_LINE;
+
+	/* Cpu */
+	if (tracer_flags.val & TRACE_GRAPH_PRINT_CPU) {
+		ret = print_graph_cpu(s, cpu);
+		if (ret == TRACE_TYPE_PARTIAL_LINE)
+			return TRACE_TYPE_PARTIAL_LINE;
+	}
+
+	/* Proc */
+	if (tracer_flags.val & TRACE_GRAPH_PRINT_PROC) {
+		ret = print_graph_proc(s, ent->pid);
+		if (ret == TRACE_TYPE_PARTIAL_LINE)
+			return TRACE_TYPE_PARTIAL_LINE;
+
+		ret = trace_seq_printf(s, " | ");
+		if (!ret)
+			return TRACE_TYPE_PARTIAL_LINE;
+	}
+
+	if (trace_branch_is_leaf(iter, field))
+		return print_graph_entry_leaf(iter, field, s);
+	else
+		return print_graph_entry_nested(field, s, iter->ent->pid, cpu);
+
+}
+
+static enum print_line_t
+print_graph_return(struct ftrace_graph_ret *trace, struct trace_seq *s,
+		   struct trace_entry *ent, int cpu)
+{
+	int i;
+	int ret;
+	unsigned long long duration = trace->rettime - trace->calltime;
+
+	/* Pid */
+	if (verif_pid(s, ent->pid, cpu) == TRACE_TYPE_PARTIAL_LINE)
+		return TRACE_TYPE_PARTIAL_LINE;
+
+	/* Cpu */
+	if (tracer_flags.val & TRACE_GRAPH_PRINT_CPU) {
+		ret = print_graph_cpu(s, cpu);
+		if (ret == TRACE_TYPE_PARTIAL_LINE)
+			return TRACE_TYPE_PARTIAL_LINE;
+	}
+
+	/* Proc */
+	if (tracer_flags.val & TRACE_GRAPH_PRINT_PROC) {
+		ret = print_graph_proc(s, ent->pid);
+		if (ret == TRACE_TYPE_PARTIAL_LINE)
+			return TRACE_TYPE_PARTIAL_LINE;
+
+		ret = trace_seq_printf(s, " | ");
+		if (!ret)
+			return TRACE_TYPE_PARTIAL_LINE;
+	}
+
+	/* Overhead */
+	if (tracer_flags.val & TRACE_GRAPH_PRINT_OVERHEAD) {
+		ret = print_graph_overhead(duration, s);
+		if (!ret)
+			return TRACE_TYPE_PARTIAL_LINE;
+	}
+
+	/* Duration */
+	ret = print_graph_duration(duration, s);
+	if (ret == TRACE_TYPE_PARTIAL_LINE)
+		return TRACE_TYPE_PARTIAL_LINE;
+
+	/* Closing brace */
+	for (i = 0; i < trace->depth * TRACE_GRAPH_INDENT; i++) {
+		ret = trace_seq_printf(s, " ");
+		if (!ret)
+			return TRACE_TYPE_PARTIAL_LINE;
+	}
+
+	ret = trace_seq_printf(s, "}\n");
+	if (!ret)
+		return TRACE_TYPE_PARTIAL_LINE;
+
+	/* Overrun */
+	if (tracer_flags.val & TRACE_GRAPH_PRINT_OVERRUN) {
+		ret = trace_seq_printf(s, " (Overruns: %lu)\n",
+					trace->overrun);
+		if (!ret)
+			return TRACE_TYPE_PARTIAL_LINE;
+	}
+
+	ret = print_graph_irq(s, trace->func, TRACE_GRAPH_RET, cpu, ent->pid);
+	if (ret == TRACE_TYPE_PARTIAL_LINE)
+		return TRACE_TYPE_PARTIAL_LINE;
+
+	return TRACE_TYPE_HANDLED;
+}
+
+static enum print_line_t
+print_graph_comment(struct print_entry *trace, struct trace_seq *s,
+		   struct trace_entry *ent, struct trace_iterator *iter)
+{
+	int i;
+	int ret;
+
+	/* Pid */
+	if (verif_pid(s, ent->pid, iter->cpu) == TRACE_TYPE_PARTIAL_LINE)
+		return TRACE_TYPE_PARTIAL_LINE;
+
+	/* Cpu */
+	if (tracer_flags.val & TRACE_GRAPH_PRINT_CPU) {
+		ret = print_graph_cpu(s, iter->cpu);
+		if (ret == TRACE_TYPE_PARTIAL_LINE)
+			return TRACE_TYPE_PARTIAL_LINE;
+	}
+
+	/* Proc */
+	if (tracer_flags.val & TRACE_GRAPH_PRINT_PROC) {
+		ret = print_graph_proc(s, ent->pid);
+		if (ret == TRACE_TYPE_PARTIAL_LINE)
+			return TRACE_TYPE_PARTIAL_LINE;
+
+		ret = trace_seq_printf(s, " | ");
+		if (!ret)
+			return TRACE_TYPE_PARTIAL_LINE;
+	}
+
+	/* No overhead */
+	if (tracer_flags.val & TRACE_GRAPH_PRINT_OVERHEAD) {
+		ret = trace_seq_printf(s, "  ");
+		if (!ret)
+			return TRACE_TYPE_PARTIAL_LINE;
+	}
+
+	/* No time */
+	ret = trace_seq_printf(s, "            |  ");
+	if (!ret)
+		return TRACE_TYPE_PARTIAL_LINE;
+
+	/* Indentation */
+	if (trace->depth > 0)
+		for (i = 0; i < (trace->depth + 1) * TRACE_GRAPH_INDENT; i++) {
+			ret = trace_seq_printf(s, " ");
+			if (!ret)
+				return TRACE_TYPE_PARTIAL_LINE;
+		}
+
+	/* The comment */
+	ret = trace_seq_printf(s, "/* %s", trace->buf);
+	if (!ret)
+		return TRACE_TYPE_PARTIAL_LINE;
+
+	if (ent->flags & TRACE_FLAG_CONT)
+		trace_seq_print_cont(s, iter);
+
+	ret = trace_seq_printf(s, " */\n");
+	if (!ret)
+		return TRACE_TYPE_PARTIAL_LINE;
+
+	return TRACE_TYPE_HANDLED;
+}
+
+
+enum print_line_t
+print_graph_function(struct trace_iterator *iter)
+{
+	struct trace_seq *s = &iter->seq;
+	struct trace_entry *entry = iter->ent;
+
+	switch (entry->type) {
+	case TRACE_GRAPH_ENT: {
+		struct ftrace_graph_ent_entry *field;
+		trace_assign_type(field, entry);
+		return print_graph_entry(field, s, iter,
+					 iter->cpu);
+	}
+	case TRACE_GRAPH_RET: {
+		struct ftrace_graph_ret_entry *field;
+		trace_assign_type(field, entry);
+		return print_graph_return(&field->ret, s, entry, iter->cpu);
+	}
+	case TRACE_PRINT: {
+		struct print_entry *field;
+		trace_assign_type(field, entry);
+		return print_graph_comment(field, s, entry, iter);
+	}
+	default:
+		return TRACE_TYPE_UNHANDLED;
+	}
+}
+
+static void print_graph_headers(struct seq_file *s)
+{
+	/* 1st line */
+	seq_printf(s, "# ");
+	if (tracer_flags.val & TRACE_GRAPH_PRINT_CPU)
+		seq_printf(s, "CPU ");
+	if (tracer_flags.val & TRACE_GRAPH_PRINT_PROC)
+		seq_printf(s, "TASK/PID     ");
+	if (tracer_flags.val & TRACE_GRAPH_PRINT_OVERHEAD)
+		seq_printf(s, "OVERHEAD/");
+	seq_printf(s, "DURATION            FUNCTION CALLS\n");
+
+	/* 2nd line */
+	seq_printf(s, "# ");
+	if (tracer_flags.val & TRACE_GRAPH_PRINT_CPU)
+		seq_printf(s, "|   ");
+	if (tracer_flags.val & TRACE_GRAPH_PRINT_PROC)
+		seq_printf(s, "|      |     ");
+	if (tracer_flags.val & TRACE_GRAPH_PRINT_OVERHEAD) {
+		seq_printf(s, "|        ");
+		seq_printf(s, "|                   |   |   |   |\n");
+	} else
+		seq_printf(s, "    |               |   |   |   |\n");
+}
+static struct tracer graph_trace __read_mostly = {
+	.name	     	= "function_graph",
+	.init	     	= graph_trace_init,
+	.reset	     	= graph_trace_reset,
+	.print_line	= print_graph_function,
+	.print_header	= print_graph_headers,
+	.flags		= &tracer_flags,
+};
+
+static __init int init_graph_trace(void)
+{
+	return register_tracer(&graph_trace);
+}
+
+device_initcall(init_graph_trace);
diff --git a/kernel/trace/trace_hw_branches.c b/kernel/trace/trace_hw_branches.c
new file mode 100644
index 0000000..b6a3e20
--- /dev/null
+++ b/kernel/trace/trace_hw_branches.c
@@ -0,0 +1,195 @@
+/*
+ * h/w branch tracer for x86 based on bts
+ *
+ * Copyright (C) 2008 Markus Metzger <markus.t.metzger@gmail.com>
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/fs.h>
+#include <linux/debugfs.h>
+#include <linux/ftrace.h>
+#include <linux/kallsyms.h>
+
+#include <asm/ds.h>
+
+#include "trace.h"
+
+
+#define SIZEOF_BTS (1 << 13)
+
+static DEFINE_PER_CPU(struct bts_tracer *, tracer);
+static DEFINE_PER_CPU(unsigned char[SIZEOF_BTS], buffer);
+
+#define this_tracer per_cpu(tracer, smp_processor_id())
+#define this_buffer per_cpu(buffer, smp_processor_id())
+
+
+static void bts_trace_start_cpu(void *arg)
+{
+	if (this_tracer)
+		ds_release_bts(this_tracer);
+
+	this_tracer =
+		ds_request_bts(/* task = */ NULL, this_buffer, SIZEOF_BTS,
+			       /* ovfl = */ NULL, /* th = */ (size_t)-1,
+			       BTS_KERNEL);
+	if (IS_ERR(this_tracer)) {
+		this_tracer = NULL;
+		return;
+	}
+}
+
+static void bts_trace_start(struct trace_array *tr)
+{
+	int cpu;
+
+	tracing_reset_online_cpus(tr);
+
+	for_each_cpu_mask(cpu, cpu_possible_map)
+		smp_call_function_single(cpu, bts_trace_start_cpu, NULL, 1);
+}
+
+static void bts_trace_stop_cpu(void *arg)
+{
+	if (this_tracer) {
+		ds_release_bts(this_tracer);
+		this_tracer = NULL;
+	}
+}
+
+static void bts_trace_stop(struct trace_array *tr)
+{
+	int cpu;
+
+	for_each_cpu_mask(cpu, cpu_possible_map)
+		smp_call_function_single(cpu, bts_trace_stop_cpu, NULL, 1);
+}
+
+static int bts_trace_init(struct trace_array *tr)
+{
+	tracing_reset_online_cpus(tr);
+	bts_trace_start(tr);
+
+	return 0;
+}
+
+static void bts_trace_print_header(struct seq_file *m)
+{
+	seq_puts(m,
+		 "# CPU#        FROM                   TO         FUNCTION\n");
+	seq_puts(m,
+		 "#  |           |                     |             |\n");
+}
+
+static enum print_line_t bts_trace_print_line(struct trace_iterator *iter)
+{
+	struct trace_entry *entry = iter->ent;
+	struct trace_seq *seq = &iter->seq;
+	struct hw_branch_entry *it;
+
+	trace_assign_type(it, entry);
+
+	if (entry->type == TRACE_HW_BRANCHES) {
+		if (trace_seq_printf(seq, "%4d  ", entry->cpu) &&
+		    trace_seq_printf(seq, "0x%016llx -> 0x%016llx ",
+				     it->from, it->to) &&
+		    (!it->from ||
+		     seq_print_ip_sym(seq, it->from, /* sym_flags = */ 0)) &&
+		    trace_seq_printf(seq, "\n"))
+			return TRACE_TYPE_HANDLED;
+		return TRACE_TYPE_PARTIAL_LINE;;
+	}
+	return TRACE_TYPE_UNHANDLED;
+}
+
+void trace_hw_branch(struct trace_array *tr, u64 from, u64 to)
+{
+	struct ring_buffer_event *event;
+	struct hw_branch_entry *entry;
+	unsigned long irq;
+
+	event = ring_buffer_lock_reserve(tr->buffer, sizeof(*entry), &irq);
+	if (!event)
+		return;
+	entry	= ring_buffer_event_data(event);
+	tracing_generic_entry_update(&entry->ent, 0, from);
+	entry->ent.type = TRACE_HW_BRANCHES;
+	entry->ent.cpu = smp_processor_id();
+	entry->from = from;
+	entry->to   = to;
+	ring_buffer_unlock_commit(tr->buffer, event, irq);
+}
+
+static void trace_bts_at(struct trace_array *tr,
+			 const struct bts_trace *trace, void *at)
+{
+	struct bts_struct bts;
+	int err = 0;
+
+	WARN_ON_ONCE(!trace->read);
+	if (!trace->read)
+		return;
+
+	err = trace->read(this_tracer, at, &bts);
+	if (err < 0)
+		return;
+
+	switch (bts.qualifier) {
+	case BTS_BRANCH:
+		trace_hw_branch(tr, bts.variant.lbr.from, bts.variant.lbr.to);
+		break;
+	}
+}
+
+static void trace_bts_cpu(void *arg)
+{
+	struct trace_array *tr = (struct trace_array *) arg;
+	const struct bts_trace *trace;
+	unsigned char *at;
+
+	if (!this_tracer)
+		return;
+
+	ds_suspend_bts(this_tracer);
+	trace = ds_read_bts(this_tracer);
+	if (!trace)
+		goto out;
+
+	for (at = trace->ds.top; (void *)at < trace->ds.end;
+	     at += trace->ds.size)
+		trace_bts_at(tr, trace, at);
+
+	for (at = trace->ds.begin; (void *)at < trace->ds.top;
+	     at += trace->ds.size)
+		trace_bts_at(tr, trace, at);
+
+out:
+	ds_resume_bts(this_tracer);
+}
+
+static void trace_bts_prepare(struct trace_iterator *iter)
+{
+	int cpu;
+
+	for_each_cpu_mask(cpu, cpu_possible_map)
+		smp_call_function_single(cpu, trace_bts_cpu, iter->tr, 1);
+}
+
+struct tracer bts_tracer __read_mostly =
+{
+	.name		= "hw-branch-tracer",
+	.init		= bts_trace_init,
+	.reset		= bts_trace_stop,
+	.print_header	= bts_trace_print_header,
+	.print_line	= bts_trace_print_line,
+	.start		= bts_trace_start,
+	.stop		= bts_trace_stop,
+	.open		= trace_bts_prepare
+};
+
+__init static int init_bts_trace(void)
+{
+	return register_tracer(&bts_tracer);
+}
+device_initcall(init_bts_trace);
diff --git a/kernel/trace/trace_irqsoff.c b/kernel/trace/trace_irqsoff.c
index 9c74071..7c2e326 100644
--- a/kernel/trace/trace_irqsoff.c
+++ b/kernel/trace/trace_irqsoff.c
@@ -353,15 +353,28 @@ void trace_preempt_off(unsigned long a0, unsigned long a1)
 }
 #endif /* CONFIG_PREEMPT_TRACER */
 
+/*
+ * save_tracer_enabled is used to save the state of the tracer_enabled
+ * variable when we disable it when we open a trace output file.
+ */
+static int save_tracer_enabled;
+
 static void start_irqsoff_tracer(struct trace_array *tr)
 {
 	register_ftrace_function(&trace_ops);
-	tracer_enabled = 1;
+	if (tracing_is_enabled()) {
+		tracer_enabled = 1;
+		save_tracer_enabled = 1;
+	} else {
+		tracer_enabled = 0;
+		save_tracer_enabled = 0;
+	}
 }
 
 static void stop_irqsoff_tracer(struct trace_array *tr)
 {
 	tracer_enabled = 0;
+	save_tracer_enabled = 0;
 	unregister_ftrace_function(&trace_ops);
 }
 
@@ -370,53 +383,55 @@ static void __irqsoff_tracer_init(struct trace_array *tr)
 	irqsoff_trace = tr;
 	/* make sure that the tracer is visible */
 	smp_wmb();
-
-	if (tr->ctrl)
-		start_irqsoff_tracer(tr);
+	start_irqsoff_tracer(tr);
 }
 
 static void irqsoff_tracer_reset(struct trace_array *tr)
 {
-	if (tr->ctrl)
-		stop_irqsoff_tracer(tr);
+	stop_irqsoff_tracer(tr);
 }
 
-static void irqsoff_tracer_ctrl_update(struct trace_array *tr)
+static void irqsoff_tracer_start(struct trace_array *tr)
 {
-	if (tr->ctrl)
-		start_irqsoff_tracer(tr);
-	else
-		stop_irqsoff_tracer(tr);
+	tracer_enabled = 1;
+	save_tracer_enabled = 1;
+}
+
+static void irqsoff_tracer_stop(struct trace_array *tr)
+{
+	tracer_enabled = 0;
+	save_tracer_enabled = 0;
 }
 
 static void irqsoff_tracer_open(struct trace_iterator *iter)
 {
 	/* stop the trace while dumping */
-	if (iter->tr->ctrl)
-		stop_irqsoff_tracer(iter->tr);
+	tracer_enabled = 0;
 }
 
 static void irqsoff_tracer_close(struct trace_iterator *iter)
 {
-	if (iter->tr->ctrl)
-		start_irqsoff_tracer(iter->tr);
+	/* restart tracing */
+	tracer_enabled = save_tracer_enabled;
 }
 
 #ifdef CONFIG_IRQSOFF_TRACER
-static void irqsoff_tracer_init(struct trace_array *tr)
+static int irqsoff_tracer_init(struct trace_array *tr)
 {
 	trace_type = TRACER_IRQS_OFF;
 
 	__irqsoff_tracer_init(tr);
+	return 0;
 }
 static struct tracer irqsoff_tracer __read_mostly =
 {
 	.name		= "irqsoff",
 	.init		= irqsoff_tracer_init,
 	.reset		= irqsoff_tracer_reset,
+	.start		= irqsoff_tracer_start,
+	.stop		= irqsoff_tracer_stop,
 	.open		= irqsoff_tracer_open,
 	.close		= irqsoff_tracer_close,
-	.ctrl_update	= irqsoff_tracer_ctrl_update,
 	.print_max	= 1,
 #ifdef CONFIG_FTRACE_SELFTEST
 	.selftest    = trace_selftest_startup_irqsoff,
@@ -428,11 +443,12 @@ static struct tracer irqsoff_tracer __read_mostly =
 #endif
 
 #ifdef CONFIG_PREEMPT_TRACER
-static void preemptoff_tracer_init(struct trace_array *tr)
+static int preemptoff_tracer_init(struct trace_array *tr)
 {
 	trace_type = TRACER_PREEMPT_OFF;
 
 	__irqsoff_tracer_init(tr);
+	return 0;
 }
 
 static struct tracer preemptoff_tracer __read_mostly =
@@ -440,9 +456,10 @@ static struct tracer preemptoff_tracer __read_mostly =
 	.name		= "preemptoff",
 	.init		= preemptoff_tracer_init,
 	.reset		= irqsoff_tracer_reset,
+	.start		= irqsoff_tracer_start,
+	.stop		= irqsoff_tracer_stop,
 	.open		= irqsoff_tracer_open,
 	.close		= irqsoff_tracer_close,
-	.ctrl_update	= irqsoff_tracer_ctrl_update,
 	.print_max	= 1,
 #ifdef CONFIG_FTRACE_SELFTEST
 	.selftest    = trace_selftest_startup_preemptoff,
@@ -456,11 +473,12 @@ static struct tracer preemptoff_tracer __read_mostly =
 #if defined(CONFIG_IRQSOFF_TRACER) && \
 	defined(CONFIG_PREEMPT_TRACER)
 
-static void preemptirqsoff_tracer_init(struct trace_array *tr)
+static int preemptirqsoff_tracer_init(struct trace_array *tr)
 {
 	trace_type = TRACER_IRQS_OFF | TRACER_PREEMPT_OFF;
 
 	__irqsoff_tracer_init(tr);
+	return 0;
 }
 
 static struct tracer preemptirqsoff_tracer __read_mostly =
@@ -468,9 +486,10 @@ static struct tracer preemptirqsoff_tracer __read_mostly =
 	.name		= "preemptirqsoff",
 	.init		= preemptirqsoff_tracer_init,
 	.reset		= irqsoff_tracer_reset,
+	.start		= irqsoff_tracer_start,
+	.stop		= irqsoff_tracer_stop,
 	.open		= irqsoff_tracer_open,
 	.close		= irqsoff_tracer_close,
-	.ctrl_update	= irqsoff_tracer_ctrl_update,
 	.print_max	= 1,
 #ifdef CONFIG_FTRACE_SELFTEST
 	.selftest    = trace_selftest_startup_preemptirqsoff,
diff --git a/kernel/trace/trace_mmiotrace.c b/kernel/trace/trace_mmiotrace.c
index e62cbf7..fffcb06 100644
--- a/kernel/trace/trace_mmiotrace.c
+++ b/kernel/trace/trace_mmiotrace.c
@@ -22,44 +22,35 @@ static unsigned long prev_overruns;
 
 static void mmio_reset_data(struct trace_array *tr)
 {
-	int cpu;
-
 	overrun_detected = false;
 	prev_overruns = 0;
-	tr->time_start = ftrace_now(tr->cpu);
 
-	for_each_online_cpu(cpu)
-		tracing_reset(tr, cpu);
+	tracing_reset_online_cpus(tr);
 }
 
-static void mmio_trace_init(struct trace_array *tr)
+static int mmio_trace_init(struct trace_array *tr)
 {
 	pr_debug("in %s\n", __func__);
 	mmio_trace_array = tr;
-	if (tr->ctrl) {
-		mmio_reset_data(tr);
-		enable_mmiotrace();
-	}
+
+	mmio_reset_data(tr);
+	enable_mmiotrace();
+	return 0;
 }
 
 static void mmio_trace_reset(struct trace_array *tr)
 {
 	pr_debug("in %s\n", __func__);
-	if (tr->ctrl)
-		disable_mmiotrace();
+
+	disable_mmiotrace();
 	mmio_reset_data(tr);
 	mmio_trace_array = NULL;
 }
 
-static void mmio_trace_ctrl_update(struct trace_array *tr)
+static void mmio_trace_start(struct trace_array *tr)
 {
 	pr_debug("in %s\n", __func__);
-	if (tr->ctrl) {
-		mmio_reset_data(tr);
-		enable_mmiotrace();
-	} else {
-		disable_mmiotrace();
-	}
+	mmio_reset_data(tr);
 }
 
 static int mmio_print_pcidev(struct trace_seq *s, const struct pci_dev *dev)
@@ -296,10 +287,10 @@ static struct tracer mmio_tracer __read_mostly =
 	.name		= "mmiotrace",
 	.init		= mmio_trace_init,
 	.reset		= mmio_trace_reset,
+	.start		= mmio_trace_start,
 	.pipe_open	= mmio_pipe_open,
 	.close		= mmio_close,
 	.read		= mmio_read,
-	.ctrl_update	= mmio_trace_ctrl_update,
 	.print_line	= mmio_print_line,
 };
 
@@ -371,5 +362,5 @@ void mmio_trace_mapping(struct mmiotrace_map *map)
 
 int mmio_trace_printk(const char *fmt, va_list args)
 {
-	return trace_vprintk(0, fmt, args);
+	return trace_vprintk(0, -1, fmt, args);
 }
diff --git a/kernel/trace/trace_nop.c b/kernel/trace/trace_nop.c
index 4592b48..b9767ac 100644
--- a/kernel/trace/trace_nop.c
+++ b/kernel/trace/trace_nop.c
@@ -12,6 +12,27 @@
 
 #include "trace.h"
 
+/* Our two options */
+enum {
+	TRACE_NOP_OPT_ACCEPT = 0x1,
+	TRACE_NOP_OPT_REFUSE = 0x2
+};
+
+/* Options for the tracer (see trace_options file) */
+static struct tracer_opt nop_opts[] = {
+	/* Option that will be accepted by set_flag callback */
+	{ TRACER_OPT(test_nop_accept, TRACE_NOP_OPT_ACCEPT) },
+	/* Option that will be refused by set_flag callback */
+	{ TRACER_OPT(test_nop_refuse, TRACE_NOP_OPT_REFUSE) },
+	{ } /* Always set a last empty entry */
+};
+
+static struct tracer_flags nop_flags = {
+	/* You can check your flags value here when you want. */
+	.val = 0, /* By default: all flags disabled */
+	.opts = nop_opts
+};
+
 static struct trace_array	*ctx_trace;
 
 static void start_nop_trace(struct trace_array *tr)
@@ -24,7 +45,7 @@ static void stop_nop_trace(struct trace_array *tr)
 	/* Nothing to do! */
 }
 
-static void nop_trace_init(struct trace_array *tr)
+static int nop_trace_init(struct trace_array *tr)
 {
 	int cpu;
 	ctx_trace = tr;
@@ -32,33 +53,53 @@ static void nop_trace_init(struct trace_array *tr)
 	for_each_online_cpu(cpu)
 		tracing_reset(tr, cpu);
 
-	if (tr->ctrl)
-		start_nop_trace(tr);
+	start_nop_trace(tr);
+	return 0;
 }
 
 static void nop_trace_reset(struct trace_array *tr)
 {
-	if (tr->ctrl)
-		stop_nop_trace(tr);
+	stop_nop_trace(tr);
 }
 
-static void nop_trace_ctrl_update(struct trace_array *tr)
+/* It only serves as a signal handler and a callback to
+ * accept or refuse tthe setting of a flag.
+ * If you don't implement it, then the flag setting will be
+ * automatically accepted.
+ */
+static int nop_set_flag(u32 old_flags, u32 bit, int set)
 {
-	/* When starting a new trace, reset the buffers */
-	if (tr->ctrl)
-		start_nop_trace(tr);
-	else
-		stop_nop_trace(tr);
+	/*
+	 * Note that you don't need to update nop_flags.val yourself.
+	 * The tracing Api will do it automatically if you return 0
+	 */
+	if (bit == TRACE_NOP_OPT_ACCEPT) {
+		printk(KERN_DEBUG "nop_test_accept flag set to %d: we accept."
+			" Now cat trace_options to see the result\n",
+			set);
+		return 0;
+	}
+
+	if (bit == TRACE_NOP_OPT_REFUSE) {
+		printk(KERN_DEBUG "nop_test_refuse flag set to %d: we refuse."
+			"Now cat trace_options to see the result\n",
+			set);
+		return -EINVAL;
+	}
+
+	return 0;
 }
 
+
 struct tracer nop_trace __read_mostly =
 {
 	.name		= "nop",
 	.init		= nop_trace_init,
 	.reset		= nop_trace_reset,
-	.ctrl_update	= nop_trace_ctrl_update,
 #ifdef CONFIG_FTRACE_SELFTEST
 	.selftest	= trace_selftest_startup_nop,
 #endif
+	.flags		= &nop_flags,
+	.set_flag	= nop_set_flag
 };
 
diff --git a/kernel/trace/trace_power.c b/kernel/trace/trace_power.c
new file mode 100644
index 0000000..a7172a3
--- /dev/null
+++ b/kernel/trace/trace_power.c
@@ -0,0 +1,179 @@
+/*
+ * ring buffer based C-state tracer
+ *
+ * Arjan van de Ven <arjan@linux.intel.com>
+ * Copyright (C) 2008 Intel Corporation
+ *
+ * Much is borrowed from trace_boot.c which is
+ * Copyright (C) 2008 Frederic Weisbecker <fweisbec@gmail.com>
+ *
+ */
+
+#include <linux/init.h>
+#include <linux/debugfs.h>
+#include <linux/ftrace.h>
+#include <linux/kallsyms.h>
+#include <linux/module.h>
+
+#include "trace.h"
+
+static struct trace_array *power_trace;
+static int __read_mostly trace_power_enabled;
+
+
+static void start_power_trace(struct trace_array *tr)
+{
+	trace_power_enabled = 1;
+}
+
+static void stop_power_trace(struct trace_array *tr)
+{
+	trace_power_enabled = 0;
+}
+
+
+static int power_trace_init(struct trace_array *tr)
+{
+	int cpu;
+	power_trace = tr;
+
+	trace_power_enabled = 1;
+
+	for_each_cpu_mask(cpu, cpu_possible_map)
+		tracing_reset(tr, cpu);
+	return 0;
+}
+
+static enum print_line_t power_print_line(struct trace_iterator *iter)
+{
+	int ret = 0;
+	struct trace_entry *entry = iter->ent;
+	struct trace_power *field ;
+	struct power_trace *it;
+	struct trace_seq *s = &iter->seq;
+	struct timespec stamp;
+	struct timespec duration;
+
+	trace_assign_type(field, entry);
+	it = &field->state_data;
+	stamp = ktime_to_timespec(it->stamp);
+	duration = ktime_to_timespec(ktime_sub(it->end, it->stamp));
+
+	if (entry->type == TRACE_POWER) {
+		if (it->type == POWER_CSTATE)
+			ret = trace_seq_printf(s, "[%5ld.%09ld] CSTATE: Going to C%i on cpu %i for %ld.%09ld\n",
+					  stamp.tv_sec,
+					  stamp.tv_nsec,
+					  it->state, iter->cpu,
+					  duration.tv_sec,
+					  duration.tv_nsec);
+		if (it->type == POWER_PSTATE)
+			ret = trace_seq_printf(s, "[%5ld.%09ld] PSTATE: Going to P%i on cpu %i\n",
+					  stamp.tv_sec,
+					  stamp.tv_nsec,
+					  it->state, iter->cpu);
+		if (!ret)
+			return TRACE_TYPE_PARTIAL_LINE;
+		return TRACE_TYPE_HANDLED;
+	}
+	return TRACE_TYPE_UNHANDLED;
+}
+
+static struct tracer power_tracer __read_mostly =
+{
+	.name		= "power",
+	.init		= power_trace_init,
+	.start		= start_power_trace,
+	.stop		= stop_power_trace,
+	.reset		= stop_power_trace,
+	.print_line	= power_print_line,
+};
+
+static int init_power_trace(void)
+{
+	return register_tracer(&power_tracer);
+}
+device_initcall(init_power_trace);
+
+void trace_power_start(struct power_trace *it, unsigned int type,
+			 unsigned int level)
+{
+	if (!trace_power_enabled)
+		return;
+
+	memset(it, 0, sizeof(struct power_trace));
+	it->state = level;
+	it->type = type;
+	it->stamp = ktime_get();
+}
+EXPORT_SYMBOL_GPL(trace_power_start);
+
+
+void trace_power_end(struct power_trace *it)
+{
+	struct ring_buffer_event *event;
+	struct trace_power *entry;
+	struct trace_array_cpu *data;
+	unsigned long irq_flags;
+	struct trace_array *tr = power_trace;
+
+	if (!trace_power_enabled)
+		return;
+
+	preempt_disable();
+	it->end = ktime_get();
+	data = tr->data[smp_processor_id()];
+
+	event = ring_buffer_lock_reserve(tr->buffer, sizeof(*entry),
+					 &irq_flags);
+	if (!event)
+		goto out;
+	entry	= ring_buffer_event_data(event);
+	tracing_generic_entry_update(&entry->ent, 0, 0);
+	entry->ent.type = TRACE_POWER;
+	entry->state_data = *it;
+	ring_buffer_unlock_commit(tr->buffer, event, irq_flags);
+
+	trace_wake_up();
+
+ out:
+	preempt_enable();
+}
+EXPORT_SYMBOL_GPL(trace_power_end);
+
+void trace_power_mark(struct power_trace *it, unsigned int type,
+			 unsigned int level)
+{
+	struct ring_buffer_event *event;
+	struct trace_power *entry;
+	struct trace_array_cpu *data;
+	unsigned long irq_flags;
+	struct trace_array *tr = power_trace;
+
+	if (!trace_power_enabled)
+		return;
+
+	memset(it, 0, sizeof(struct power_trace));
+	it->state = level;
+	it->type = type;
+	it->stamp = ktime_get();
+	preempt_disable();
+	it->end = it->stamp;
+	data = tr->data[smp_processor_id()];
+
+	event = ring_buffer_lock_reserve(tr->buffer, sizeof(*entry),
+					 &irq_flags);
+	if (!event)
+		goto out;
+	entry	= ring_buffer_event_data(event);
+	tracing_generic_entry_update(&entry->ent, 0, 0);
+	entry->ent.type = TRACE_POWER;
+	entry->state_data = *it;
+	ring_buffer_unlock_commit(tr->buffer, event, irq_flags);
+
+	trace_wake_up();
+
+ out:
+	preempt_enable();
+}
+EXPORT_SYMBOL_GPL(trace_power_mark);
diff --git a/kernel/trace/trace_sched_switch.c b/kernel/trace/trace_sched_switch.c
index b8f56be..df175cb 100644
--- a/kernel/trace/trace_sched_switch.c
+++ b/kernel/trace/trace_sched_switch.c
@@ -16,7 +16,8 @@
 
 static struct trace_array	*ctx_trace;
 static int __read_mostly	tracer_enabled;
-static atomic_t			sched_ref;
+static int			sched_ref;
+static DEFINE_MUTEX(sched_register_mutex);
 
 static void
 probe_sched_switch(struct rq *__rq, struct task_struct *prev,
@@ -27,7 +28,7 @@ probe_sched_switch(struct rq *__rq, struct task_struct *prev,
 	int cpu;
 	int pc;
 
-	if (!atomic_read(&sched_ref))
+	if (!sched_ref)
 		return;
 
 	tracing_record_cmdline(prev);
@@ -48,7 +49,7 @@ probe_sched_switch(struct rq *__rq, struct task_struct *prev,
 }
 
 static void
-probe_sched_wakeup(struct rq *__rq, struct task_struct *wakee)
+probe_sched_wakeup(struct rq *__rq, struct task_struct *wakee, int success)
 {
 	struct trace_array_cpu *data;
 	unsigned long flags;
@@ -71,16 +72,6 @@ probe_sched_wakeup(struct rq *__rq, struct task_struct *wakee)
 	local_irq_restore(flags);
 }
 
-static void sched_switch_reset(struct trace_array *tr)
-{
-	int cpu;
-
-	tr->time_start = ftrace_now(tr->cpu);
-
-	for_each_online_cpu(cpu)
-		tracing_reset(tr, cpu);
-}
-
 static int tracing_sched_register(void)
 {
 	int ret;
@@ -123,20 +114,18 @@ static void tracing_sched_unregister(void)
 
 static void tracing_start_sched_switch(void)
 {
-	long ref;
-
-	ref = atomic_inc_return(&sched_ref);
-	if (ref == 1)
+	mutex_lock(&sched_register_mutex);
+	if (!(sched_ref++))
 		tracing_sched_register();
+	mutex_unlock(&sched_register_mutex);
 }
 
 static void tracing_stop_sched_switch(void)
 {
-	long ref;
-
-	ref = atomic_dec_and_test(&sched_ref);
-	if (ref)
+	mutex_lock(&sched_register_mutex);
+	if (!(--sched_ref))
 		tracing_sched_unregister();
+	mutex_unlock(&sched_register_mutex);
 }
 
 void tracing_start_cmdline_record(void)
@@ -149,40 +138,86 @@ void tracing_stop_cmdline_record(void)
 	tracing_stop_sched_switch();
 }
 
+/**
+ * tracing_start_sched_switch_record - start tracing context switches
+ *
+ * Turns on context switch tracing for a tracer.
+ */
+void tracing_start_sched_switch_record(void)
+{
+	if (unlikely(!ctx_trace)) {
+		WARN_ON(1);
+		return;
+	}
+
+	tracing_start_sched_switch();
+
+	mutex_lock(&sched_register_mutex);
+	tracer_enabled++;
+	mutex_unlock(&sched_register_mutex);
+}
+
+/**
+ * tracing_stop_sched_switch_record - start tracing context switches
+ *
+ * Turns off context switch tracing for a tracer.
+ */
+void tracing_stop_sched_switch_record(void)
+{
+	mutex_lock(&sched_register_mutex);
+	tracer_enabled--;
+	WARN_ON(tracer_enabled < 0);
+	mutex_unlock(&sched_register_mutex);
+
+	tracing_stop_sched_switch();
+}
+
+/**
+ * tracing_sched_switch_assign_trace - assign a trace array for ctx switch
+ * @tr: trace array pointer to assign
+ *
+ * Some tracers might want to record the context switches in their
+ * trace. This function lets those tracers assign the trace array
+ * to use.
+ */
+void tracing_sched_switch_assign_trace(struct trace_array *tr)
+{
+	ctx_trace = tr;
+}
+
 static void start_sched_trace(struct trace_array *tr)
 {
-	sched_switch_reset(tr);
-	tracing_start_cmdline_record();
-	tracer_enabled = 1;
+	tracing_reset_online_cpus(tr);
+	tracing_start_sched_switch_record();
 }
 
 static void stop_sched_trace(struct trace_array *tr)
 {
-	tracer_enabled = 0;
-	tracing_stop_cmdline_record();
+	tracing_stop_sched_switch_record();
 }
 
-static void sched_switch_trace_init(struct trace_array *tr)
+static int sched_switch_trace_init(struct trace_array *tr)
 {
 	ctx_trace = tr;
-
-	if (tr->ctrl)
-		start_sched_trace(tr);
+	start_sched_trace(tr);
+	return 0;
 }
 
 static void sched_switch_trace_reset(struct trace_array *tr)
 {
-	if (tr->ctrl)
+	if (sched_ref)
 		stop_sched_trace(tr);
 }
 
-static void sched_switch_trace_ctrl_update(struct trace_array *tr)
+static void sched_switch_trace_start(struct trace_array *tr)
 {
-	/* When starting a new trace, reset the buffers */
-	if (tr->ctrl)
-		start_sched_trace(tr);
-	else
-		stop_sched_trace(tr);
+	tracing_reset_online_cpus(tr);
+	tracing_start_sched_switch();
+}
+
+static void sched_switch_trace_stop(struct trace_array *tr)
+{
+	tracing_stop_sched_switch();
 }
 
 static struct tracer sched_switch_trace __read_mostly =
@@ -190,7 +225,8 @@ static struct tracer sched_switch_trace __read_mostly =
 	.name		= "sched_switch",
 	.init		= sched_switch_trace_init,
 	.reset		= sched_switch_trace_reset,
-	.ctrl_update	= sched_switch_trace_ctrl_update,
+	.start		= sched_switch_trace_start,
+	.stop		= sched_switch_trace_stop,
 #ifdef CONFIG_FTRACE_SELFTEST
 	.selftest    = trace_selftest_startup_sched_switch,
 #endif
@@ -198,14 +234,7 @@ static struct tracer sched_switch_trace __read_mostly =
 
 __init static int init_sched_switch_trace(void)
 {
-	int ret = 0;
-
-	if (atomic_read(&sched_ref))
-		ret = tracing_sched_register();
-	if (ret) {
-		pr_info("error registering scheduler trace\n");
-		return ret;
-	}
 	return register_tracer(&sched_switch_trace);
 }
 device_initcall(init_sched_switch_trace);
+
diff --git a/kernel/trace/trace_sched_wakeup.c b/kernel/trace/trace_sched_wakeup.c
index 3ae93f1..43586b6 100644
--- a/kernel/trace/trace_sched_wakeup.c
+++ b/kernel/trace/trace_sched_wakeup.c
@@ -50,8 +50,7 @@ wakeup_tracer_call(unsigned long ip, unsigned long parent_ip)
 		return;
 
 	pc = preempt_count();
-	resched = need_resched();
-	preempt_disable_notrace();
+	resched = ftrace_preempt_disable();
 
 	cpu = raw_smp_processor_id();
 	data = tr->data[cpu];
@@ -81,15 +80,7 @@ wakeup_tracer_call(unsigned long ip, unsigned long parent_ip)
  out:
 	atomic_dec(&data->disabled);
 
-	/*
-	 * To prevent recursion from the scheduler, if the
-	 * resched flag was set before we entered, then
-	 * don't reschedule.
-	 */
-	if (resched)
-		preempt_enable_no_resched_notrace();
-	else
-		preempt_enable_notrace();
+	ftrace_preempt_enable(resched);
 }
 
 static struct ftrace_ops trace_ops __read_mostly =
@@ -220,7 +211,7 @@ static void wakeup_reset(struct trace_array *tr)
 }
 
 static void
-probe_wakeup(struct rq *rq, struct task_struct *p)
+probe_wakeup(struct rq *rq, struct task_struct *p, int success)
 {
 	int cpu = smp_processor_id();
 	unsigned long flags;
@@ -271,6 +262,12 @@ out:
 	atomic_dec(&wakeup_trace->data[cpu]->disabled);
 }
 
+/*
+ * save_tracer_enabled is used to save the state of the tracer_enabled
+ * variable when we disable it when we open a trace output file.
+ */
+static int save_tracer_enabled;
+
 static void start_wakeup_tracer(struct trace_array *tr)
 {
 	int ret;
@@ -309,7 +306,13 @@ static void start_wakeup_tracer(struct trace_array *tr)
 
 	register_ftrace_function(&trace_ops);
 
-	tracer_enabled = 1;
+	if (tracing_is_enabled()) {
+		tracer_enabled = 1;
+		save_tracer_enabled = 1;
+	} else {
+		tracer_enabled = 0;
+		save_tracer_enabled = 0;
+	}
 
 	return;
 fail_deprobe_wake_new:
@@ -321,49 +324,53 @@ fail_deprobe:
 static void stop_wakeup_tracer(struct trace_array *tr)
 {
 	tracer_enabled = 0;
+	save_tracer_enabled = 0;
 	unregister_ftrace_function(&trace_ops);
 	unregister_trace_sched_switch(probe_wakeup_sched_switch);
 	unregister_trace_sched_wakeup_new(probe_wakeup);
 	unregister_trace_sched_wakeup(probe_wakeup);
 }
 
-static void wakeup_tracer_init(struct trace_array *tr)
+static int wakeup_tracer_init(struct trace_array *tr)
 {
 	wakeup_trace = tr;
-
-	if (tr->ctrl)
-		start_wakeup_tracer(tr);
+	start_wakeup_tracer(tr);
+	return 0;
 }
 
 static void wakeup_tracer_reset(struct trace_array *tr)
 {
-	if (tr->ctrl) {
-		stop_wakeup_tracer(tr);
-		/* make sure we put back any tasks we are tracing */
-		wakeup_reset(tr);
-	}
+	stop_wakeup_tracer(tr);
+	/* make sure we put back any tasks we are tracing */
+	wakeup_reset(tr);
+}
+
+static void wakeup_tracer_start(struct trace_array *tr)
+{
+	wakeup_reset(tr);
+	tracer_enabled = 1;
+	save_tracer_enabled = 1;
 }
 
-static void wakeup_tracer_ctrl_update(struct trace_array *tr)
+static void wakeup_tracer_stop(struct trace_array *tr)
 {
-	if (tr->ctrl)
-		start_wakeup_tracer(tr);
-	else
-		stop_wakeup_tracer(tr);
+	tracer_enabled = 0;
+	save_tracer_enabled = 0;
 }
 
 static void wakeup_tracer_open(struct trace_iterator *iter)
 {
 	/* stop the trace while dumping */
-	if (iter->tr->ctrl)
-		stop_wakeup_tracer(iter->tr);
+	tracer_enabled = 0;
 }
 
 static void wakeup_tracer_close(struct trace_iterator *iter)
 {
 	/* forget about any processes we were recording */
-	if (iter->tr->ctrl)
-		start_wakeup_tracer(iter->tr);
+	if (save_tracer_enabled) {
+		wakeup_reset(iter->tr);
+		tracer_enabled = 1;
+	}
 }
 
 static struct tracer wakeup_tracer __read_mostly =
@@ -371,9 +378,10 @@ static struct tracer wakeup_tracer __read_mostly =
 	.name		= "wakeup",
 	.init		= wakeup_tracer_init,
 	.reset		= wakeup_tracer_reset,
+	.start		= wakeup_tracer_start,
+	.stop		= wakeup_tracer_stop,
 	.open		= wakeup_tracer_open,
 	.close		= wakeup_tracer_close,
-	.ctrl_update	= wakeup_tracer_ctrl_update,
 	.print_max	= 1,
 #ifdef CONFIG_FTRACE_SELFTEST
 	.selftest    = trace_selftest_startup_wakeup,
diff --git a/kernel/trace/trace_selftest.c b/kernel/trace/trace_selftest.c
index 90bc752..88c8eb7 100644
--- a/kernel/trace/trace_selftest.c
+++ b/kernel/trace/trace_selftest.c
@@ -13,6 +13,7 @@ static inline int trace_valid_entry(struct trace_entry *entry)
 	case TRACE_STACK:
 	case TRACE_PRINT:
 	case TRACE_SPECIAL:
+	case TRACE_BRANCH:
 		return 1;
 	}
 	return 0;
@@ -51,7 +52,7 @@ static int trace_test_buffer(struct trace_array *tr, unsigned long *count)
 	int cpu, ret = 0;
 
 	/* Don't allow flipping of max traces now */
-	raw_local_irq_save(flags);
+	local_irq_save(flags);
 	__raw_spin_lock(&ftrace_max_lock);
 
 	cnt = ring_buffer_entries(tr->buffer);
@@ -62,7 +63,7 @@ static int trace_test_buffer(struct trace_array *tr, unsigned long *count)
 			break;
 	}
 	__raw_spin_unlock(&ftrace_max_lock);
-	raw_local_irq_restore(flags);
+	local_irq_restore(flags);
 
 	if (count)
 		*count = cnt;
@@ -70,6 +71,11 @@ static int trace_test_buffer(struct trace_array *tr, unsigned long *count)
 	return ret;
 }
 
+static inline void warn_failed_init_tracer(struct tracer *trace, int init_ret)
+{
+	printk(KERN_WARNING "Failed to init %s tracer, init returned %d\n",
+		trace->name, init_ret);
+}
 #ifdef CONFIG_FUNCTION_TRACER
 
 #ifdef CONFIG_DYNAMIC_FTRACE
@@ -110,8 +116,11 @@ int trace_selftest_startup_dynamic_tracing(struct tracer *trace,
 	ftrace_set_filter(func_name, strlen(func_name), 1);
 
 	/* enable tracing */
-	tr->ctrl = 1;
-	trace->init(tr);
+	ret = trace->init(tr);
+	if (ret) {
+		warn_failed_init_tracer(trace, ret);
+		goto out;
+	}
 
 	/* Sleep for a 1/10 of a second */
 	msleep(100);
@@ -134,13 +143,13 @@ int trace_selftest_startup_dynamic_tracing(struct tracer *trace,
 	msleep(100);
 
 	/* stop the tracing. */
-	tr->ctrl = 0;
-	trace->ctrl_update(tr);
+	tracing_stop();
 	ftrace_enabled = 0;
 
 	/* check the trace buffer */
 	ret = trace_test_buffer(tr, &count);
 	trace->reset(tr);
+	tracing_start();
 
 	/* we should only have one item */
 	if (!ret && count != 1) {
@@ -148,6 +157,7 @@ int trace_selftest_startup_dynamic_tracing(struct tracer *trace,
 		ret = -1;
 		goto out;
 	}
+
  out:
 	ftrace_enabled = save_ftrace_enabled;
 	tracer_enabled = save_tracer_enabled;
@@ -180,18 +190,22 @@ trace_selftest_startup_function(struct tracer *trace, struct trace_array *tr)
 	ftrace_enabled = 1;
 	tracer_enabled = 1;
 
-	tr->ctrl = 1;
-	trace->init(tr);
+	ret = trace->init(tr);
+	if (ret) {
+		warn_failed_init_tracer(trace, ret);
+		goto out;
+	}
+
 	/* Sleep for a 1/10 of a second */
 	msleep(100);
 	/* stop the tracing. */
-	tr->ctrl = 0;
-	trace->ctrl_update(tr);
+	tracing_stop();
 	ftrace_enabled = 0;
 
 	/* check the trace buffer */
 	ret = trace_test_buffer(tr, &count);
 	trace->reset(tr);
+	tracing_start();
 
 	if (!ret && !count) {
 		printk(KERN_CONT ".. no entries found ..");
@@ -223,8 +237,12 @@ trace_selftest_startup_irqsoff(struct tracer *trace, struct trace_array *tr)
 	int ret;
 
 	/* start the tracing */
-	tr->ctrl = 1;
-	trace->init(tr);
+	ret = trace->init(tr);
+	if (ret) {
+		warn_failed_init_tracer(trace, ret);
+		return ret;
+	}
+
 	/* reset the max latency */
 	tracing_max_latency = 0;
 	/* disable interrupts for a bit */
@@ -232,13 +250,13 @@ trace_selftest_startup_irqsoff(struct tracer *trace, struct trace_array *tr)
 	udelay(100);
 	local_irq_enable();
 	/* stop the tracing. */
-	tr->ctrl = 0;
-	trace->ctrl_update(tr);
+	tracing_stop();
 	/* check both trace buffers */
 	ret = trace_test_buffer(tr, NULL);
 	if (!ret)
 		ret = trace_test_buffer(&max_tr, &count);
 	trace->reset(tr);
+	tracing_start();
 
 	if (!ret && !count) {
 		printk(KERN_CONT ".. no entries found ..");
@@ -259,9 +277,26 @@ trace_selftest_startup_preemptoff(struct tracer *trace, struct trace_array *tr)
 	unsigned long count;
 	int ret;
 
+	/*
+	 * Now that the big kernel lock is no longer preemptable,
+	 * and this is called with the BKL held, it will always
+	 * fail. If preemption is already disabled, simply
+	 * pass the test. When the BKL is removed, or becomes
+	 * preemptible again, we will once again test this,
+	 * so keep it in.
+	 */
+	if (preempt_count()) {
+		printk(KERN_CONT "can not test ... force ");
+		return 0;
+	}
+
 	/* start the tracing */
-	tr->ctrl = 1;
-	trace->init(tr);
+	ret = trace->init(tr);
+	if (ret) {
+		warn_failed_init_tracer(trace, ret);
+		return ret;
+	}
+
 	/* reset the max latency */
 	tracing_max_latency = 0;
 	/* disable preemption for a bit */
@@ -269,13 +304,13 @@ trace_selftest_startup_preemptoff(struct tracer *trace, struct trace_array *tr)
 	udelay(100);
 	preempt_enable();
 	/* stop the tracing. */
-	tr->ctrl = 0;
-	trace->ctrl_update(tr);
+	tracing_stop();
 	/* check both trace buffers */
 	ret = trace_test_buffer(tr, NULL);
 	if (!ret)
 		ret = trace_test_buffer(&max_tr, &count);
 	trace->reset(tr);
+	tracing_start();
 
 	if (!ret && !count) {
 		printk(KERN_CONT ".. no entries found ..");
@@ -296,9 +331,25 @@ trace_selftest_startup_preemptirqsoff(struct tracer *trace, struct trace_array *
 	unsigned long count;
 	int ret;
 
+	/*
+	 * Now that the big kernel lock is no longer preemptable,
+	 * and this is called with the BKL held, it will always
+	 * fail. If preemption is already disabled, simply
+	 * pass the test. When the BKL is removed, or becomes
+	 * preemptible again, we will once again test this,
+	 * so keep it in.
+	 */
+	if (preempt_count()) {
+		printk(KERN_CONT "can not test ... force ");
+		return 0;
+	}
+
 	/* start the tracing */
-	tr->ctrl = 1;
-	trace->init(tr);
+	ret = trace->init(tr);
+	if (ret) {
+		warn_failed_init_tracer(trace, ret);
+		goto out;
+	}
 
 	/* reset the max latency */
 	tracing_max_latency = 0;
@@ -312,27 +363,30 @@ trace_selftest_startup_preemptirqsoff(struct tracer *trace, struct trace_array *
 	local_irq_enable();
 
 	/* stop the tracing. */
-	tr->ctrl = 0;
-	trace->ctrl_update(tr);
+	tracing_stop();
 	/* check both trace buffers */
 	ret = trace_test_buffer(tr, NULL);
-	if (ret)
+	if (ret) {
+		tracing_start();
 		goto out;
+	}
 
 	ret = trace_test_buffer(&max_tr, &count);
-	if (ret)
+	if (ret) {
+		tracing_start();
 		goto out;
+	}
 
 	if (!ret && !count) {
 		printk(KERN_CONT ".. no entries found ..");
 		ret = -1;
+		tracing_start();
 		goto out;
 	}
 
 	/* do the test by disabling interrupts first this time */
 	tracing_max_latency = 0;
-	tr->ctrl = 1;
-	trace->ctrl_update(tr);
+	tracing_start();
 	preempt_disable();
 	local_irq_disable();
 	udelay(100);
@@ -341,8 +395,7 @@ trace_selftest_startup_preemptirqsoff(struct tracer *trace, struct trace_array *
 	local_irq_enable();
 
 	/* stop the tracing. */
-	tr->ctrl = 0;
-	trace->ctrl_update(tr);
+	tracing_stop();
 	/* check both trace buffers */
 	ret = trace_test_buffer(tr, NULL);
 	if (ret)
@@ -358,6 +411,7 @@ trace_selftest_startup_preemptirqsoff(struct tracer *trace, struct trace_array *
 
  out:
 	trace->reset(tr);
+	tracing_start();
 	tracing_max_latency = save_max;
 
 	return ret;
@@ -423,8 +477,12 @@ trace_selftest_startup_wakeup(struct tracer *trace, struct trace_array *tr)
 	wait_for_completion(&isrt);
 
 	/* start the tracing */
-	tr->ctrl = 1;
-	trace->init(tr);
+	ret = trace->init(tr);
+	if (ret) {
+		warn_failed_init_tracer(trace, ret);
+		return ret;
+	}
+
 	/* reset the max latency */
 	tracing_max_latency = 0;
 
@@ -448,8 +506,7 @@ trace_selftest_startup_wakeup(struct tracer *trace, struct trace_array *tr)
 	msleep(100);
 
 	/* stop the tracing. */
-	tr->ctrl = 0;
-	trace->ctrl_update(tr);
+	tracing_stop();
 	/* check both trace buffers */
 	ret = trace_test_buffer(tr, NULL);
 	if (!ret)
@@ -457,6 +514,7 @@ trace_selftest_startup_wakeup(struct tracer *trace, struct trace_array *tr)
 
 
 	trace->reset(tr);
+	tracing_start();
 
 	tracing_max_latency = save_max;
 
@@ -480,16 +538,20 @@ trace_selftest_startup_sched_switch(struct tracer *trace, struct trace_array *tr
 	int ret;
 
 	/* start the tracing */
-	tr->ctrl = 1;
-	trace->init(tr);
+	ret = trace->init(tr);
+	if (ret) {
+		warn_failed_init_tracer(trace, ret);
+		return ret;
+	}
+
 	/* Sleep for a 1/10 of a second */
 	msleep(100);
 	/* stop the tracing. */
-	tr->ctrl = 0;
-	trace->ctrl_update(tr);
+	tracing_stop();
 	/* check the trace buffer */
 	ret = trace_test_buffer(tr, &count);
 	trace->reset(tr);
+	tracing_start();
 
 	if (!ret && !count) {
 		printk(KERN_CONT ".. no entries found ..");
@@ -508,17 +570,48 @@ trace_selftest_startup_sysprof(struct tracer *trace, struct trace_array *tr)
 	int ret;
 
 	/* start the tracing */
-	tr->ctrl = 1;
-	trace->init(tr);
+	ret = trace->init(tr);
+	if (ret) {
+		warn_failed_init_tracer(trace, ret);
+		return 0;
+	}
+
 	/* Sleep for a 1/10 of a second */
 	msleep(100);
 	/* stop the tracing. */
-	tr->ctrl = 0;
-	trace->ctrl_update(tr);
+	tracing_stop();
 	/* check the trace buffer */
 	ret = trace_test_buffer(tr, &count);
 	trace->reset(tr);
+	tracing_start();
 
 	return ret;
 }
 #endif /* CONFIG_SYSPROF_TRACER */
+
+#ifdef CONFIG_BRANCH_TRACER
+int
+trace_selftest_startup_branch(struct tracer *trace, struct trace_array *tr)
+{
+	unsigned long count;
+	int ret;
+
+	/* start the tracing */
+	ret = trace->init(tr);
+	if (ret) {
+		warn_failed_init_tracer(trace, ret);
+		return ret;
+	}
+
+	/* Sleep for a 1/10 of a second */
+	msleep(100);
+	/* stop the tracing. */
+	tracing_stop();
+	/* check the trace buffer */
+	ret = trace_test_buffer(tr, &count);
+	trace->reset(tr);
+	tracing_start();
+
+	return ret;
+}
+#endif /* CONFIG_BRANCH_TRACER */
diff --git a/kernel/trace/trace_stack.c b/kernel/trace/trace_stack.c
index 3bdb44b..d0871bc 100644
--- a/kernel/trace/trace_stack.c
+++ b/kernel/trace/trace_stack.c
@@ -10,6 +10,7 @@
 #include <linux/debugfs.h>
 #include <linux/ftrace.h>
 #include <linux/module.h>
+#include <linux/sysctl.h>
 #include <linux/init.h>
 #include <linux/fs.h>
 #include "trace.h"
@@ -31,6 +32,10 @@ static raw_spinlock_t max_stack_lock =
 
 static int stack_trace_disabled __read_mostly;
 static DEFINE_PER_CPU(int, trace_active);
+static DEFINE_MUTEX(stack_sysctl_mutex);
+
+int stack_tracer_enabled;
+static int last_stack_tracer_enabled;
 
 static inline void check_stack(void)
 {
@@ -48,7 +53,7 @@ static inline void check_stack(void)
 	if (!object_is_on_stack(&this_size))
 		return;
 
-	raw_local_irq_save(flags);
+	local_irq_save(flags);
 	__raw_spin_lock(&max_stack_lock);
 
 	/* a race could have already updated it */
@@ -78,6 +83,7 @@ static inline void check_stack(void)
 	 * on a new max, so it is far from a fast path.
 	 */
 	while (i < max_stack_trace.nr_entries) {
+		int found = 0;
 
 		stack_dump_index[i] = this_size;
 		p = start;
@@ -86,17 +92,19 @@ static inline void check_stack(void)
 			if (*p == stack_dump_trace[i]) {
 				this_size = stack_dump_index[i++] =
 					(top - p) * sizeof(unsigned long);
+				found = 1;
 				/* Start the search from here */
 				start = p + 1;
 			}
 		}
 
-		i++;
+		if (!found)
+			i++;
 	}
 
  out:
 	__raw_spin_unlock(&max_stack_lock);
-	raw_local_irq_restore(flags);
+	local_irq_restore(flags);
 }
 
 static void
@@ -107,8 +115,7 @@ stack_trace_call(unsigned long ip, unsigned long parent_ip)
 	if (unlikely(!ftrace_enabled || stack_trace_disabled))
 		return;
 
-	resched = need_resched();
-	preempt_disable_notrace();
+	resched = ftrace_preempt_disable();
 
 	cpu = raw_smp_processor_id();
 	/* no atomic needed, we only modify this variable by this cpu */
@@ -120,10 +127,7 @@ stack_trace_call(unsigned long ip, unsigned long parent_ip)
  out:
 	per_cpu(trace_active, cpu)--;
 	/* prevent recursion in schedule */
-	if (resched)
-		preempt_enable_no_resched_notrace();
-	else
-		preempt_enable_notrace();
+	ftrace_preempt_enable(resched);
 }
 
 static struct ftrace_ops trace_ops __read_mostly =
@@ -166,16 +170,16 @@ stack_max_size_write(struct file *filp, const char __user *ubuf,
 	if (ret < 0)
 		return ret;
 
-	raw_local_irq_save(flags);
+	local_irq_save(flags);
 	__raw_spin_lock(&max_stack_lock);
 	*ptr = val;
 	__raw_spin_unlock(&max_stack_lock);
-	raw_local_irq_restore(flags);
+	local_irq_restore(flags);
 
 	return count;
 }
 
-static struct file_operations stack_max_size_fops = {
+static const struct file_operations stack_max_size_fops = {
 	.open		= tracing_open_generic,
 	.read		= stack_max_size_read,
 	.write		= stack_max_size_write,
@@ -273,7 +277,7 @@ static int t_show(struct seq_file *m, void *v)
 	return 0;
 }
 
-static struct seq_operations stack_trace_seq_ops = {
+static const struct seq_operations stack_trace_seq_ops = {
 	.start		= t_start,
 	.next		= t_next,
 	.stop		= t_stop,
@@ -289,12 +293,47 @@ static int stack_trace_open(struct inode *inode, struct file *file)
 	return ret;
 }
 
-static struct file_operations stack_trace_fops = {
+static const struct file_operations stack_trace_fops = {
 	.open		= stack_trace_open,
 	.read		= seq_read,
 	.llseek		= seq_lseek,
 };
 
+int
+stack_trace_sysctl(struct ctl_table *table, int write,
+		   struct file *file, void __user *buffer, size_t *lenp,
+		   loff_t *ppos)
+{
+	int ret;
+
+	mutex_lock(&stack_sysctl_mutex);
+
+	ret = proc_dointvec(table, write, file, buffer, lenp, ppos);
+
+	if (ret || !write ||
+	    (last_stack_tracer_enabled == stack_tracer_enabled))
+		goto out;
+
+	last_stack_tracer_enabled = stack_tracer_enabled;
+
+	if (stack_tracer_enabled)
+		register_ftrace_function(&trace_ops);
+	else
+		unregister_ftrace_function(&trace_ops);
+
+ out:
+	mutex_unlock(&stack_sysctl_mutex);
+	return ret;
+}
+
+static __init int enable_stacktrace(char *str)
+{
+	stack_tracer_enabled = 1;
+	last_stack_tracer_enabled = 1;
+	return 1;
+}
+__setup("stacktrace", enable_stacktrace);
+
 static __init int stack_trace_init(void)
 {
 	struct dentry *d_tracer;
@@ -312,7 +351,8 @@ static __init int stack_trace_init(void)
 	if (!entry)
 		pr_warning("Could not create debugfs 'stack_trace' entry\n");
 
-	register_ftrace_function(&trace_ops);
+	if (stack_tracer_enabled)
+		register_ftrace_function(&trace_ops);
 
 	return 0;
 }
diff --git a/kernel/trace/trace_sysprof.c b/kernel/trace/trace_sysprof.c
index 9587d3b..01becf1 100644
--- a/kernel/trace/trace_sysprof.c
+++ b/kernel/trace/trace_sysprof.c
@@ -234,20 +234,10 @@ static void stop_stack_timers(void)
 		stop_stack_timer(cpu);
 }
 
-static void stack_reset(struct trace_array *tr)
-{
-	int cpu;
-
-	tr->time_start = ftrace_now(tr->cpu);
-
-	for_each_online_cpu(cpu)
-		tracing_reset(tr, cpu);
-}
-
 static void start_stack_trace(struct trace_array *tr)
 {
 	mutex_lock(&sample_timer_lock);
-	stack_reset(tr);
+	tracing_reset_online_cpus(tr);
 	start_stack_timers();
 	tracer_enabled = 1;
 	mutex_unlock(&sample_timer_lock);
@@ -261,27 +251,17 @@ static void stop_stack_trace(struct trace_array *tr)
 	mutex_unlock(&sample_timer_lock);
 }
 
-static void stack_trace_init(struct trace_array *tr)
+static int stack_trace_init(struct trace_array *tr)
 {
 	sysprof_trace = tr;
 
-	if (tr->ctrl)
-		start_stack_trace(tr);
+	start_stack_trace(tr);
+	return 0;
 }
 
 static void stack_trace_reset(struct trace_array *tr)
 {
-	if (tr->ctrl)
-		stop_stack_trace(tr);
-}
-
-static void stack_trace_ctrl_update(struct trace_array *tr)
-{
-	/* When starting a new trace, reset the buffers */
-	if (tr->ctrl)
-		start_stack_trace(tr);
-	else
-		stop_stack_trace(tr);
+	stop_stack_trace(tr);
 }
 
 static struct tracer stack_trace __read_mostly =
@@ -289,7 +269,6 @@ static struct tracer stack_trace __read_mostly =
 	.name		= "sysprof",
 	.init		= stack_trace_init,
 	.reset		= stack_trace_reset,
-	.ctrl_update	= stack_trace_ctrl_update,
 #ifdef CONFIG_FTRACE_SELFTEST
 	.selftest    = trace_selftest_startup_sysprof,
 #endif