From c812fe636b6e1e3b3b409b316157f56054252e25 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Thu, 17 May 2012 17:15:29 +0200 Subject: sched/nohz: Fix rq->cpu_load calculations some more commit 5aaa0b7a2ed5b12692c9ffb5222182bd558d3146 upstream. Follow up on commit 556061b00 ("sched/nohz: Fix rq->cpu_load[] calculations") since while that fixed the busy case it regressed the mostly idle case. Add a callback from the nohz exit to also age the rq->cpu_load[] array. This closes the hole where either there was no nohz load balance pass during the nohz, or there was a 'significant' amount of idle time between the last nohz balance and the nohz exit. So we'll update unconditionally from the tick to not insert any accidental 0 load periods while busy, and we try and catch up from nohz idle balance and nohz exit. Both these are still prone to missing a jiffy, but that has always been the case. Signed-off-by: Peter Zijlstra Cc: pjt@google.com Cc: Venkatesh Pallipadi Link: http://lkml.kernel.org/n/tip-kt0trz0apodbf84ucjfdbr1a@git.kernel.org Signed-off-by: Ingo Molnar [bwh: Backported to 3.2: adjust filenames and context] Signed-off-by: Ben Hutchings --- include/linux/sched.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include') diff --git a/include/linux/sched.h b/include/linux/sched.h index a96cb8c1d82..d336c359676 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -145,6 +145,7 @@ extern unsigned long this_cpu_load(void); extern void calc_global_load(unsigned long ticks); +extern void update_cpu_load_nohz(void); extern unsigned long get_parent_ip(unsigned long addr); -- cgit v1.2.3-18-g5258