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| author | Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> | 2009-11-26 14:48:30 +0900 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2009-11-26 12:59:19 +0100 |
| commit | d180c5bccec02612256fd8076ff3c1fac3429553 (patch) | |
| tree | 1ef4a45c81531645640380965916c68bbe7f6abb /fs/proc/array.c | |
| parent | 16bc67edeb49b531940b2ba6c183780a1b5c472d (diff) | |
| download | lwn-d180c5bccec02612256fd8076ff3c1fac3429553.tar.gz lwn-d180c5bccec02612256fd8076ff3c1fac3429553.zip | |
sched: Introduce task_times() to replace task_{u,s}time() pair
Functions task_{u,s}time() are called in pair in almost all
cases. However task_stime() is implemented to call task_utime()
from its inside, so such paired calls run task_utime() twice.
It means we do heavy divisions (div_u64 + do_div) twice to get
utime and stime which can be obtained at same time by one set
of divisions.
This patch introduces a function task_times(*tsk, *utime,
*stime) to retrieve utime and stime at once in better, optimized
way.
Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Stanislaw Gruszka <sgruszka@redhat.com>
Cc: Spencer Candland <spencer@bluehost.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Americo Wang <xiyou.wangcong@gmail.com>
LKML-Reference: <4B0E16AE.906@jp.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'fs/proc/array.c')
| -rw-r--r-- | fs/proc/array.c | 3 |
1 files changed, 1 insertions, 2 deletions
diff --git a/fs/proc/array.c b/fs/proc/array.c index e209f64ab27b..330deda70d08 100644 --- a/fs/proc/array.c +++ b/fs/proc/array.c @@ -535,8 +535,7 @@ static int do_task_stat(struct seq_file *m, struct pid_namespace *ns, if (!whole) { min_flt = task->min_flt; maj_flt = task->maj_flt; - utime = task_utime(task); - stime = task_stime(task); + task_times(task, &utime, &stime); gtime = task_gtime(task); } |