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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
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10
kernel/tsacct.c
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@@ -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;