[PATCH] sched: add missing call for calc_load_exit_idle

[PATCH] sched: add missing call for calc_load_exit_idle

[Charles Wang]

>From Charles Wang <muming.wq@taobao.com>

Azat Khuzhin reported "high loadavg in linux-3.6"

After checking for upstream's code, I found Peter's patch
(Commit id:5167e8d5417bf5c322a703d2927daec727ea40dd) not be
fully applied, missing the call for calc_load_exit_idle.
After that idle exit in sampling window will always be calculated
 to non-idle, and the load will be higher than normal.

This patch add the missing call for calc_load_exit_idle.

Signed-off-by: Charles Wang <muming.wq@taobao.com>

diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
index 024540f..3a9e5d5 100644
--- a/kernel/time/tick-sched.c
+++ b/kernel/time/tick-sched.c
@@ -573,6 +573,7 @@ static void tick_nohz_restart_sched_tick(struct tick_sched *ts, ktime_t now)
 	tick_do_update_jiffies64(now);
 	update_cpu_load_nohz();
 
+	calc_load_exit_idle();
 	touch_softlockup_watchdog();
 	/*
 	 * Cancel the scheduled timer and restore the tick
-- 
1.7.9.5

Re: [PATCH] sched: add missing call for calc_load_exit_idle

[Charles Wang]

No email address provided by Azat Khuzhin, so I don't know
how to let him know this. - -!

On 08/20/2012 04:02 PM, Charles Wang wrote:
>  From Charles Wang <muming.wq@taobao.com>
>
> Azat Khuzhin reported "high loadavg in linux-3.6"
>
> After checking for upstream's code, I found Peter's patch
> (Commit id:5167e8d5417bf5c322a703d2927daec727ea40dd) not be
> fully applied, missing the call for calc_load_exit_idle.
> After that idle exit in sampling window will always be calculated
>   to non-idle, and the load will be higher than normal.
>
> This patch add the missing call for calc_load_exit_idle.
>
> Signed-off-by: Charles Wang <muming.wq@taobao.com>
>
> diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
> index 024540f..3a9e5d5 100644
> --- a/kernel/time/tick-sched.c
> +++ b/kernel/time/tick-sched.c
> @@ -573,6 +573,7 @@ static void tick_nohz_restart_sched_tick(struct tick_sched *ts, ktime_t now)
>   	tick_do_update_jiffies64(now);
>   	update_cpu_load_nohz();
>
> +	calc_load_exit_idle();
>   	touch_softlockup_watchdog();
>   	/*
>   	 * Cancel the scheduled timer and restore the tick
>

Re: [PATCH] sched: add missing call for calc_load_exit_idle

[Peter Zijlstra]

On Mon, 2012-08-20 at 16:02 +0800, Charles Wang wrote:
> From Charles Wang <muming.wq@taobao.com>
> 
> Azat Khuzhin reported "high loadavg in linux-3.6"
> 
> After checking for upstream's code, I found Peter's patch
> (Commit id:5167e8d5417bf5c322a703d2927daec727ea40dd) not be
> fully applied, missing the call for calc_load_exit_idle.
> After that idle exit in sampling window will always be calculated
>  to non-idle, and the load will be higher than normal.
> 
> This patch add the missing call for calc_load_exit_idle.
> 
> Signed-off-by: Charles Wang <muming.wq@taobao.com>

Argh! how the @#$# did that happen..

Thanks for spotting it.

[tip:sched/core] sched: Add missing call to calc_load_exit_idle()

[tip-bot for Charles Wang]

Commit-ID:  749c8814f08f12baa4a9c2812a7c6ede7d69507d
Gitweb:     http://git.kernel.org/tip/749c8814f08f12baa4a9c2812a7c6ede7d69507d
Author:     Charles Wang <muming.wq@taobao.com>
AuthorDate: Mon, 20 Aug 2012 16:02:33 +0800
Committer:  Ingo Molnar <mingo@kernel.org>
CommitDate: Tue, 4 Sep 2012 14:30:29 +0200

sched: Add missing call to calc_load_exit_idle()

Azat Khuzhin reported high loadavg in Linux v3.6

After checking the upstream scheduler code, I found Peter's commit:

  5167e8d5417b sched/nohz: Rewrite and fix load-avg computation -- again

not fully applied, missing the call to calc_load_exit_idle().

After that idle exit in sampling window will always be calculated
to non-idle, and the load will be higher than normal.

This patch adds the missing call to calc_load_exit_idle().

Signed-off-by: Charles Wang <muming.wq@taobao.com>
Cc: stable@kernel.org
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1345449754-27130-1-git-send-email-muming.wq@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
 kernel/time/tick-sched.c |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)

diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
index 024540f..3a9e5d5 100644
--- a/kernel/time/tick-sched.c
+++ b/kernel/time/tick-sched.c
@@ -573,6 +573,7 @@ static void tick_nohz_restart_sched_tick(struct tick_sched *ts, ktime_t now)
 	tick_do_update_jiffies64(now);
 	update_cpu_load_nohz();
 
+	calc_load_exit_idle();
 	touch_softlockup_watchdog();
 	/*
 	 * Cancel the scheduled timer and restore the tick