From: Dimitri Sivanich <sivanich@sgi.com>
To: Thomas Gleixner <tglx@linutronix.de>
Cc: LKML <linux-kernel@vger.kernel.org>,
Andrew Morton <akpm@linux-foundation.org>,
Peter Zijlstra <peterz@infradead.org>,
Ingo Molnar <mingo@elte.hu>
Subject: Re: [patch 0/2] sched, timers: simplify calc_load and avoid cpu iteration loop
Date: Fri, 15 May 2009 07:23:08 -0500 [thread overview]
Message-ID: <20090515122308.GA11465@sgi.com> (raw)
In-Reply-To: <20090514105915.973318588@linutronix.de>
Acked-by: Dimitri Sivanich <sivanich@sgi.com>
On Thu, May 14, 2009 at 11:21:14AM -0000, Thomas Gleixner wrote:
> Dimitri Sivanich pointed out that calc_load iterates over all online
> CPUs under xtime lock which can cause long latencies on large SMP
> systems.
>
> The following patch series removes the iteration loop and lets
> scheduler_tick() on each CPU update the number of active tasks. The
> calc_load() function just uses this variable and updates avenrun from
> do_timer().
>
> Dimitri, can you please test run this on one of your large machines ?
>
> Thanks,
>
> tglx
>
prev parent reply other threads:[~2009-05-15 12:28 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-05-14 11:21 [patch 0/2] sched, timers: simplify calc_load and avoid cpu iteration loop Thomas Gleixner
2009-05-14 11:21 ` [patch 1/2] sched, timers: move calc_load() to scheduler Thomas Gleixner
2009-05-14 20:00 ` Peter Zijlstra
2009-05-14 20:40 ` Thomas Gleixner
2009-05-15 5:13 ` Peter Zijlstra
2009-05-14 11:21 ` [patch 2/2] sched, timers: cleanup avenrun users Thomas Gleixner
2009-05-14 17:23 ` [patch 0/2] sched, timers: simplify calc_load and avoid cpu iteration loop Dimitri Sivanich
2009-05-14 19:26 ` Thomas Gleixner
2009-05-15 12:23 ` Dimitri Sivanich [this message]
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