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taskstats: use real microsecond granularity for CPU times

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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@linux.vnet.ibm.com>
Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Cc: Luck Tony <tony.luck@intel.com>
Cc: Shailabh Nagar <nagar1234@in.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Shailabh Nagar <nagar@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Michael Holzheu 2010-10-27 15:34:45 -07:00 committed by Linus Torvalds
parent 3d9e0cf1fe
commit d57af9b214
5 changed files with 21 additions and 23 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

6
arch/ia64/include/asm/cputime.h
View File

@ -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

12
arch/powerpc/include/asm/cputime.h
View File

@ -124,23 +124,23 @@ static inline u64 cputime64_to_jiffies64(const cputime_t ct)
}
/*
* 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);

10
arch/s390/include/asm/cputime.h
View File

@ -73,18 +73,18 @@ cputime64_to_jiffies64(cputime64_t cputime)
}
/*
* 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;
}
/*

6
include/asm-generic/cputime.h
View File

@ -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.

10
kernel/tsacct.c
View File

@ -63,12 +63,10 @@ void bacct_add_tsk(struct taskstats *stats, struct task_struct *tsk)
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;