The patch titled
taskstats: use real microsecond granularity for CPU times
has been added to the -mm tree. Its filename is
taskstats-use-real-microsecond-granularity-for-cpu-times.patch
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------------------------------------------------------
Subject: taskstats: use real microsecond granularity for CPU times
From: Michael Holzheu <holzheu@xxxxxxxxxxxxxxxxxx>
The taskstats interface uses microsecond granularity for the user and
system time values. The conversion from cputime to the taskstats values
uses the cputime_to_msecs primitive which effectively limits the
granularity to milliseconds. Add the cputime_to_usecs primitive for
architectures that have better, more precise CPU time values. Remove
cputime_to_msecs primitive because there are no more users left.
Signed-off-by: Michael Holzheu <holzheu@xxxxxxxxxxxxxxxxxx>
Acked-by: Balbir Singh <balbir@xxxxxxxxxxxxxxxxxx>
Cc: Luck Tony <tony.luck@xxxxxxxxx>
Cc: Shailabh Nagar <nagar1234@xxxxxxxxxx>
Cc: Martin Schwidefsky <schwidefsky@xxxxxxxxxx>
Cc: Oleg Nesterov <oleg@xxxxxxxxxx>
Cc: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
Cc: Heiko Carstens <heiko.carstens@xxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Shailabh Nagar <nagar@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
arch/ia64/include/asm/cputime.h | 6 +++---
arch/powerpc/include/asm/cputime.h | 12 ++++++------
arch/s390/include/asm/cputime.h | 10 +++++-----
include/asm-generic/cputime.h | 6 +++---
kernel/tsacct.c | 10 ++++------
5 files changed, 21 insertions(+), 23 deletions(-)
diff -puN arch/ia64/include/asm/cputime.h~taskstats-use-real-microsecond-granularity-for-cpu-times arch/ia64/include/asm/cputime.h
--- a/arch/ia64/include/asm/cputime.h~taskstats-use-real-microsecond-granularity-for-cpu-times
+++ a/arch/ia64/include/asm/cputime.h
@@ -56,10 +56,10 @@ typedef u64 cputime64_t;
#define jiffies64_to_cputime64(__jif) ((__jif) * (NSEC_PER_SEC / HZ))
/*
- * Convert cputime <-> milliseconds
+ * Convert cputime <-> microseconds
*/
-#define cputime_to_msecs(__ct) ((__ct) / NSEC_PER_MSEC)
-#define msecs_to_cputime(__msecs) ((__msecs) * NSEC_PER_MSEC)
+#define cputime_to_usecs(__ct) ((__ct) / NSEC_PER_USEC)
+#define usecs_to_cputime(__usecs) ((__usecs) * NSEC_PER_USEC)
/*
* Convert cputime <-> seconds
diff -puN arch/powerpc/include/asm/cputime.h~taskstats-use-real-microsecond-granularity-for-cpu-times arch/powerpc/include/asm/cputime.h
--- a/arch/powerpc/include/asm/cputime.h~taskstats-use-real-microsecond-granularity-for-cpu-times
+++ a/arch/powerpc/include/asm/cputime.h
@@ -124,23 +124,23 @@ static inline u64 cputime64_to_jiffies64
}
/*
- * Convert cputime <-> milliseconds
+ * Convert cputime <-> microseconds
*/
extern u64 __cputime_msec_factor;
-static inline unsigned long cputime_to_msecs(const cputime_t ct)
+static inline unsigned long cputime_to_usecs(const cputime_t ct)
{
- return mulhdu(ct, __cputime_msec_factor);
+ return mulhdu(ct, __cputime_msec_factor) * USEC_PER_MSEC;
}
-static inline cputime_t msecs_to_cputime(const unsigned long ms)
+static inline cputime_t usecs_to_cputime(const unsigned long us)
{
cputime_t ct;
unsigned long sec;
/* have to be a little careful about overflow */
- ct = ms % 1000;
- sec = ms / 1000;
+ ct = us % 1000000;
+ sec = us / 1000000;
if (ct) {
ct *= tb_ticks_per_sec;
do_div(ct, 1000);
diff -puN arch/s390/include/asm/cputime.h~taskstats-use-real-microsecond-granularity-for-cpu-times arch/s390/include/asm/cputime.h
--- a/arch/s390/include/asm/cputime.h~taskstats-use-real-microsecond-granularity-for-cpu-times
+++ a/arch/s390/include/asm/cputime.h
@@ -73,18 +73,18 @@ cputime64_to_jiffies64(cputime64_t cputi
}
/*
- * Convert cputime to milliseconds and back.
+ * Convert cputime to microseconds and back.
*/
static inline unsigned int
-cputime_to_msecs(const cputime_t cputime)
+cputime_to_usecs(const cputime_t cputime)
{
- return cputime_div(cputime, 4096000);
+ return cputime_div(cputime, 4096);
}
static inline cputime_t
-msecs_to_cputime(const unsigned int m)
+usecs_to_cputime(const unsigned int m)
{
- return (cputime_t) m * 4096000;
+ return (cputime_t) m * 4096;
}
/*
diff -puN include/asm-generic/cputime.h~taskstats-use-real-microsecond-granularity-for-cpu-times include/asm-generic/cputime.h
--- a/include/asm-generic/cputime.h~taskstats-use-real-microsecond-granularity-for-cpu-times
+++ a/include/asm-generic/cputime.h
@@ -33,10 +33,10 @@ typedef u64 cputime64_t;
/*
- * Convert cputime to milliseconds and back.
+ * Convert cputime to microseconds and back.
*/
-#define cputime_to_msecs(__ct) jiffies_to_msecs(__ct)
-#define msecs_to_cputime(__msecs) msecs_to_jiffies(__msecs)
+#define cputime_to_usecs(__ct) jiffies_to_usecs(__ct);
+#define usecs_to_cputime(__msecs) usecs_to_jiffies(__msecs);
/*
* Convert cputime to seconds and back.
diff -puN kernel/tsacct.c~taskstats-use-real-microsecond-granularity-for-cpu-times kernel/tsacct.c
--- a/kernel/tsacct.c~taskstats-use-real-microsecond-granularity-for-cpu-times
+++ a/kernel/tsacct.c
@@ -63,12 +63,10 @@ void bacct_add_tsk(struct taskstats *sta
stats->ac_ppid = pid_alive(tsk) ?
rcu_dereference(tsk->real_parent)->tgid : 0;
rcu_read_unlock();
- stats->ac_utime = cputime_to_msecs(tsk->utime) * USEC_PER_MSEC;
- stats->ac_stime = cputime_to_msecs(tsk->stime) * USEC_PER_MSEC;
- stats->ac_utimescaled =
- cputime_to_msecs(tsk->utimescaled) * USEC_PER_MSEC;
- stats->ac_stimescaled =
- cputime_to_msecs(tsk->stimescaled) * USEC_PER_MSEC;
+ stats->ac_utime = cputime_to_usecs(tsk->utime);
+ stats->ac_stime = cputime_to_usecs(tsk->stime);
+ stats->ac_utimescaled = cputime_to_usecs(tsk->utimescaled);
+ stats->ac_stimescaled = cputime_to_usecs(tsk->stimescaled);
stats->ac_minflt = tsk->min_flt;
stats->ac_majflt = tsk->maj_flt;
_
Patches currently in -mm which might be from holzheu@xxxxxxxxxxxxxxxxxx are
linux-next.patch
taskstats-separate-taskstats-commands.patch
taskstats-split-fill_pid-function.patch
taskstats-use-real-microsecond-granularity-for-cpu-times.patch
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