From d180c5bccec02612256fd8076ff3c1fac3429553 Mon Sep 17 00:00:00 2001 From: Hidetoshi Seto Date: Thu, 26 Nov 2009 14:48:30 +0900 Subject: 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 Acked-by: Peter Zijlstra Cc: Stanislaw Gruszka Cc: Spencer Candland Cc: Oleg Nesterov Cc: Balbir Singh Cc: Americo Wang LKML-Reference: <4B0E16AE.906@jp.fujitsu.com> Signed-off-by: Ingo Molnar --- kernel/sys.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) (limited to 'kernel/sys.c') diff --git a/kernel/sys.c b/kernel/sys.c index ce17760d9c51..bbdfce0d4347 100644 --- a/kernel/sys.c +++ b/kernel/sys.c @@ -1346,8 +1346,7 @@ static void k_getrusage(struct task_struct *p, int who, struct rusage *r) utime = stime = cputime_zero; if (who == RUSAGE_THREAD) { - utime = task_utime(current); - stime = task_stime(current); + task_times(current, &utime, &stime); accumulate_thread_rusage(p, r); maxrss = p->signal->maxrss; goto out; -- cgit v1.2.3