Merge tag 'full-dynticks-cputime-for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git/frederic/linux-dynticks into sched/core

Pull full-dynticks (user-space execution is undisturbed and
receives no timer IRQs) preparation changes that convert the
cputime accounting code to be full-dynticks ready,
from Frederic Weisbecker:

 "This implements the cputime accounting on full dynticks CPUs.

  Typical cputime stats infrastructure relies on the timer tick and
  its periodic polling on the CPU to account the amount of time
  spent by the CPUs and the tasks per high level domains such as
  userspace, kernelspace, guest, ...

  Now we are preparing to implement full dynticks capability on
  Linux for Real Time and HPC users who want full CPU isolation.
  This feature requires a cputime accounting that doesn't depend
  on the timer tick.

  To implement it, this new cputime infrastructure plugs into
  kernel/user/guest boundaries to take snapshots of cputime and
  flush these to the stats when needed. This performs pretty
  much like CONFIG_VIRT_CPU_ACCOUNTING except that context location
  and cputime snaphots are synchronized between write and read
  side such that the latter can safely retrieve the pending tickless
  cputime of a task and add it to its latest cputime snapshot to
  return the correct result to the user."

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>

3 files changed, 182 insertions, 60 deletions

diff --git a/include/asm-generic/cputime.h b/include/asm-generic/cputime.h
index 9a62937..5196943 100644
--- a/include/asm-generic/cputime.h
+++ b/include/asm-generic/cputime.h
@@ -4,66 +4,12 @@
 #include <linux/time.h>
 #include <linux/jiffies.h>
 
-typedef unsigned long __nocast cputime_t;
-
-#define cputime_one_jiffy		jiffies_to_cputime(1)
-#define cputime_to_jiffies(__ct)	(__force unsigned long)(__ct)
-#define cputime_to_scaled(__ct)		(__ct)
-#define jiffies_to_cputime(__hz)	(__force cputime_t)(__hz)
-
-typedef u64 __nocast cputime64_t;
-
-#define cputime64_to_jiffies64(__ct)	(__force u64)(__ct)
-#define jiffies64_to_cputime64(__jif)	(__force cputime64_t)(__jif)
-
-#define nsecs_to_cputime64(__ct)	\
-	jiffies64_to_cputime64(nsecs_to_jiffies64(__ct))
-
-
-/*
- * Convert cputime to microseconds and back.
- */
-#define cputime_to_usecs(__ct)		\
-	jiffies_to_usecs(cputime_to_jiffies(__ct))
-#define usecs_to_cputime(__usec)	\
-	jiffies_to_cputime(usecs_to_jiffies(__usec))
-#define usecs_to_cputime64(__usec)	\
-	jiffies64_to_cputime64(nsecs_to_jiffies64((__usec) * 1000))
-
-/*
- * Convert cputime to seconds and back.
- */
-#define cputime_to_secs(jif)		(cputime_to_jiffies(jif) / HZ)
-#define secs_to_cputime(sec)		jiffies_to_cputime((sec) * HZ)
-
-/*
- * Convert cputime to timespec and back.
- */
-#define timespec_to_cputime(__val)	\
-	jiffies_to_cputime(timespec_to_jiffies(__val))
-#define cputime_to_timespec(__ct,__val)	\
-	jiffies_to_timespec(cputime_to_jiffies(__ct),__val)
-
-/*
- * Convert cputime to timeval and back.
- */
-#define timeval_to_cputime(__val)	\
-	jiffies_to_cputime(timeval_to_jiffies(__val))
-#define cputime_to_timeval(__ct,__val)	\
-	jiffies_to_timeval(cputime_to_jiffies(__ct),__val)
-
-/*
- * Convert cputime to clock and back.
- */
-#define cputime_to_clock_t(__ct)	\
-	jiffies_to_clock_t(cputime_to_jiffies(__ct))
-#define clock_t_to_cputime(__x)		\
-	jiffies_to_cputime(clock_t_to_jiffies(__x))
+#ifndef CONFIG_VIRT_CPU_ACCOUNTING
+# include <asm-generic/cputime_jiffies.h>
+#endif
 
-/*
- * Convert cputime64 to clock.
- */
-#define cputime64_to_clock_t(__ct)	\
-	jiffies_64_to_clock_t(cputime64_to_jiffies64(__ct))
+#ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
+# include <asm-generic/cputime_nsecs.h>
+#endif
 
 #endif
diff --git a/include/asm-generic/cputime_jiffies.h b/include/asm-generic/cputime_jiffies.h
new file mode 100644
index 0000000..272ecba
--- /dev/null
+++ b/include/asm-generic/cputime_jiffies.h
@@ -0,0 +1,72 @@
+#ifndef _ASM_GENERIC_CPUTIME_JIFFIES_H
+#define _ASM_GENERIC_CPUTIME_JIFFIES_H
+
+typedef unsigned long __nocast cputime_t;
+
+#define cputime_one_jiffy		jiffies_to_cputime(1)
+#define cputime_to_jiffies(__ct)	(__force unsigned long)(__ct)
+#define cputime_to_scaled(__ct)		(__ct)
+#define jiffies_to_cputime(__hz)	(__force cputime_t)(__hz)
+
+typedef u64 __nocast cputime64_t;
+
+#define cputime64_to_jiffies64(__ct)	(__force u64)(__ct)
+#define jiffies64_to_cputime64(__jif)	(__force cputime64_t)(__jif)
+
+
+/*
+ * Convert nanoseconds to cputime
+ */
+#define nsecs_to_cputime64(__nsec)	\
+	jiffies64_to_cputime64(nsecs_to_jiffies64(__nsec))
+#define nsecs_to_cputime(__nsec)	\
+	jiffies_to_cputime(nsecs_to_jiffies(__nsec))
+
+
+/*
+ * Convert cputime to microseconds and back.
+ */
+#define cputime_to_usecs(__ct)		\
+	jiffies_to_usecs(cputime_to_jiffies(__ct))
+#define usecs_to_cputime(__usec)	\
+	jiffies_to_cputime(usecs_to_jiffies(__usec))
+#define usecs_to_cputime64(__usec)	\
+	jiffies64_to_cputime64(nsecs_to_jiffies64((__usec) * 1000))
+
+/*
+ * Convert cputime to seconds and back.
+ */
+#define cputime_to_secs(jif)		(cputime_to_jiffies(jif) / HZ)
+#define secs_to_cputime(sec)		jiffies_to_cputime((sec) * HZ)
+
+/*
+ * Convert cputime to timespec and back.
+ */
+#define timespec_to_cputime(__val)	\
+	jiffies_to_cputime(timespec_to_jiffies(__val))
+#define cputime_to_timespec(__ct,__val)	\
+	jiffies_to_timespec(cputime_to_jiffies(__ct),__val)
+
+/*
+ * Convert cputime to timeval and back.
+ */
+#define timeval_to_cputime(__val)	\
+	jiffies_to_cputime(timeval_to_jiffies(__val))
+#define cputime_to_timeval(__ct,__val)	\
+	jiffies_to_timeval(cputime_to_jiffies(__ct),__val)
+
+/*
+ * Convert cputime to clock and back.
+ */
+#define cputime_to_clock_t(__ct)	\
+	jiffies_to_clock_t(cputime_to_jiffies(__ct))
+#define clock_t_to_cputime(__x)		\
+	jiffies_to_cputime(clock_t_to_jiffies(__x))
+
+/*
+ * Convert cputime64 to clock.
+ */
+#define cputime64_to_clock_t(__ct)	\
+	jiffies_64_to_clock_t(cputime64_to_jiffies64(__ct))
+
+#endif
diff --git a/include/asm-generic/cputime_nsecs.h b/include/asm-generic/cputime_nsecs.h
new file mode 100644
index 0000000..b6485ca
--- /dev/null
+++ b/include/asm-generic/cputime_nsecs.h
@@ -0,0 +1,104 @@
+/*
+ * Definitions for measuring cputime in nsecs resolution.
+ *
+ * Based on <arch/ia64/include/asm/cputime.h>
+ *
+ * Copyright (C) 2007 FUJITSU LIMITED
+ * Copyright (C) 2007 Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ *
+ */
+
+#ifndef _ASM_GENERIC_CPUTIME_NSECS_H
+#define _ASM_GENERIC_CPUTIME_NSECS_H
+
+typedef u64 __nocast cputime_t;
+typedef u64 __nocast cputime64_t;
+
+#define cputime_one_jiffy		jiffies_to_cputime(1)
+
+/*
+ * Convert cputime <-> jiffies (HZ)
+ */
+#define cputime_to_jiffies(__ct)	\
+	((__force u64)(__ct) / (NSEC_PER_SEC / HZ))
+#define cputime_to_scaled(__ct)		(__ct)
+#define jiffies_to_cputime(__jif)	\
+	(__force cputime_t)((__jif) * (NSEC_PER_SEC / HZ))
+#define cputime64_to_jiffies64(__ct)	\
+	((__force u64)(__ct) / (NSEC_PER_SEC / HZ))
+#define jiffies64_to_cputime64(__jif)	\
+	(__force cputime64_t)((__jif) * (NSEC_PER_SEC / HZ))
+
+
+/*
+ * Convert cputime <-> nanoseconds
+ */
+#define nsecs_to_cputime(__nsecs)	((__force u64)(__nsecs))
+
+
+/*
+ * Convert cputime <-> microseconds
+ */
+#define cputime_to_usecs(__ct)		\
+	((__force u64)(__ct) / NSEC_PER_USEC)
+#define usecs_to_cputime(__usecs)	\
+	(__force cputime_t)((__usecs) * NSEC_PER_USEC)
+#define usecs_to_cputime64(__usecs)	\
+	(__force cputime64_t)((__usecs) * NSEC_PER_USEC)
+
+/*
+ * Convert cputime <-> seconds
+ */
+#define cputime_to_secs(__ct)		\
+	((__force u64)(__ct) / NSEC_PER_SEC)
+#define secs_to_cputime(__secs)		\
+	(__force cputime_t)((__secs) * NSEC_PER_SEC)
+
+/*
+ * Convert cputime <-> timespec (nsec)
+ */
+static inline cputime_t timespec_to_cputime(const struct timespec *val)
+{
+	u64 ret = val->tv_sec * NSEC_PER_SEC + val->tv_nsec;
+	return (__force cputime_t) ret;
+}
+static inline void cputime_to_timespec(const cputime_t ct, struct timespec *val)
+{
+	val->tv_sec  = (__force u64) ct / NSEC_PER_SEC;
+	val->tv_nsec = (__force u64) ct % NSEC_PER_SEC;
+}
+
+/*
+ * Convert cputime <-> timeval (msec)
+ */
+static inline cputime_t timeval_to_cputime(struct timeval *val)
+{
+	u64 ret = val->tv_sec * NSEC_PER_SEC + val->tv_usec * NSEC_PER_USEC;
+	return (__force cputime_t) ret;
+}
+static inline void cputime_to_timeval(const cputime_t ct, struct timeval *val)
+{
+	val->tv_sec = (__force u64) ct / NSEC_PER_SEC;
+	val->tv_usec = ((__force u64) ct % NSEC_PER_SEC) / NSEC_PER_USEC;
+}
+
+/*
+ * Convert cputime <-> clock (USER_HZ)
+ */
+#define cputime_to_clock_t(__ct)	\
+	((__force u64)(__ct) / (NSEC_PER_SEC / USER_HZ))
+#define clock_t_to_cputime(__x)		\
+	(__force cputime_t)((__x) * (NSEC_PER_SEC / USER_HZ))
+
+/*
+ * Convert cputime64 to clock.
+ */
+#define cputime64_to_clock_t(__ct)	\
+	cputime_to_clock_t((__force cputime_t)__ct)
+
+#endif