From: Ingo Molnar <mingo@elte.hu>
To: Linux Kernel <linux-kernel@vger.kernel.org>,
Dhaval Giani <dhaval@linux.vnet.ibm.com>,
Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>,
Vaidyanathan S <svaidyan@in.ibm.com>,
Peter Zijlstra <a.p.zijlstra@chello.nl>,
Bharata B Rao <bharata@linux.vnet.ibm.com>
Subject: Re: [PATCH][mmotm] Sched fix stale value in average load per task
Date: Wed, 12 Nov 2008 12:35:14 +0100 [thread overview]
Message-ID: <20081112113514.GB6372@elte.hu> (raw)
In-Reply-To: <20081112104900.GA13896@balbir.in.ibm.com>
* Balbir Singh <balbir@linux.vnet.ibm.com> wrote:
> cpu_avg_load_per_task() returns a stale value when nr_running is 0.
> It returns an older stale (caculated when nr_running was non zero)
> value. This patch returns and sets rq->avg_load_per_task to zero
> when nr_running is 0.
>
> Compile and boot tested on a x86_64 box.
>
> Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com>
> ---
>
> kernel/sched.c | 2 ++
> 1 file changed, 2 insertions(+)
applied to tip/sched/urgent, thanks Balbir!
i'm wondering, have you observed load-balancer misbehavior due to this
load-average imprecision bug, on some workload? (or have you found
this via code review)
Ingo
next prev parent reply other threads:[~2008-11-12 11:35 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-11-12 10:49 [PATCH][mmotm] Sched fix stale value in average load per task Balbir Singh
2008-11-12 11:35 ` Ingo Molnar [this message]
2008-11-12 11:52 ` Balbir Singh
2008-11-12 11:38 ` Balbir Singh
2008-11-12 11:46 ` Ingo Molnar
2008-11-12 11:53 ` Balbir Singh
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