diff options
| author | Frederic Weisbecker <fweisbec@gmail.com> | 2008-12-06 03:43:41 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2008-12-08 15:11:45 +0100 |
| commit | 380c4b1411ccd6885f92b2c8ceb08433a720f44e (patch) | |
| tree | f3b571e1caff2de3e6b4cace87c2b1ec332667d7 /kernel/trace | |
| parent | 8e1b82e0866befaa0b2920be296c6e4c3fc7f422 (diff) | |
| download | kernel_goldelico_gta04-380c4b1411ccd6885f92b2c8ceb08433a720f44e.zip kernel_goldelico_gta04-380c4b1411ccd6885f92b2c8ceb08433a720f44e.tar.gz kernel_goldelico_gta04-380c4b1411ccd6885f92b2c8ceb08433a720f44e.tar.bz2 | |
tracing/function-graph-tracer: append the tracing_graph_flag
Impact: Provide a way to pause the function graph tracer
As suggested by Steven Rostedt, the previous patch that prevented from
spinlock function tracing shouldn't use the raw_spinlock to fix it.
It's much better to follow lockdep with normal spinlock, so this patch
adds a new flag for each task to make the function graph tracer able
to be paused. We also can send an ftrace_printk whithout worrying of
the irrelevant traced spinlock during insertion.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel/trace')
| -rw-r--r-- | kernel/trace/ftrace.c | 2 | ||||
| -rw-r--r-- | kernel/trace/trace.c | 18 |
2 files changed, 7 insertions, 13 deletions
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 2971fe4..a12f80e 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -1998,6 +1998,7 @@ static int alloc_retstack_tasklist(struct ftrace_ret_stack **ret_stack_list) /* 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); @@ -2077,6 +2078,7 @@ void ftrace_graph_init_task(struct task_struct *t) 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; diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 3354953..0b8659b 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -3590,14 +3590,7 @@ static __init int tracer_init_debugfs(void) int trace_vprintk(unsigned long ip, int depth, const char *fmt, va_list args) { - /* - * Raw Spinlock because a normal spinlock would be traced here - * and append an irrelevant couple spin_lock_irqsave/ - * spin_unlock_irqrestore traced by ftrace around this - * TRACE_PRINTK trace. - */ - static raw_spinlock_t trace_buf_lock = - (raw_spinlock_t)__RAW_SPIN_LOCK_UNLOCKED; + static DEFINE_SPINLOCK(trace_buf_lock); static char trace_buf[TRACE_BUF_SIZE]; struct ring_buffer_event *event; @@ -3618,8 +3611,8 @@ int trace_vprintk(unsigned long ip, int depth, const char *fmt, va_list args) if (unlikely(atomic_read(&data->disabled))) goto out; - local_irq_save(flags); - __raw_spin_lock(&trace_buf_lock); + 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); @@ -3640,9 +3633,8 @@ int trace_vprintk(unsigned long ip, int depth, const char *fmt, va_list args) ring_buffer_unlock_commit(tr->buffer, event, irq_flags); out_unlock: - __raw_spin_unlock(&trace_buf_lock); - local_irq_restore(flags); - + spin_unlock_irqrestore(&trace_buf_lock, irq_flags); + unpause_graph_tracing(); out: preempt_enable_notrace(); |