summary refs log tree commit diff
path: root/fs/proc
diff options
context:
space:
mode:
authorHidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>2009-11-26 14:48:30 +0900
committerIngo Molnar <mingo@elte.hu>2009-11-26 12:59:19 +0100
commitd180c5bccec02612256fd8076ff3c1fac3429553 (patch)
tree1ef4a45c81531645640380965916c68bbe7f6abb /fs/proc
parent16bc67edeb49b531940b2ba6c183780a1b5c472d (diff)
downloadlinux-d180c5bccec02612256fd8076ff3c1fac3429553.tar.gz
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')
-rw-r--r--fs/proc/array.c3
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);
 	}