From: Peter Zijlstra <peterz@infradead.org>
To: Lei Wen <adrian.wenl@gmail.com>
Cc: Paul Turner <pjt@google.com>,
linux-kernel@vger.kernel.org, Ingo Molnar <mingo@kernel.org>,
leiwen@marvell.com
Subject: Re: false nr_running check in load balance?
Date: Tue, 13 Aug 2013 09:38:42 +0200 [thread overview]
Message-ID: <20130813073842.GP27162@twins.programming.kicks-ass.net> (raw)
In-Reply-To: <CALZhoSRyfE78GbiJqVRvUrbJRq_NhSqYbK8vnxNP8kS9xz9qVQ@mail.gmail.com>
On Tue, Aug 13, 2013 at 12:45:12PM +0800, Lei Wen wrote:
> > Not quite right; I think you need busiest->cfs.h_nr_running.
> > cfs.nr_running is the number of entries running in this 'group'. If
> > you've got nested groups like:
> >
> > 'root'
> > \
> > 'A'
> > / \
> > t1 t2
> >
> > root.nr_running := 1 'A', even though you've got multiple running tasks.
> >
>
> You're absolutely right for this. :)
> I miss it for not considering the group case...
>
> Then do you think it is necessary to do below change in load_balance() code?
> - if (busiest->nr_running > 1) {
> + if (busiest->cfs.h_nr_running > 1) {
>
Yes I think that would be fine.
next prev parent reply other threads:[~2013-08-13 7:38 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-08-06 13:23 Lei Wen
2013-08-12 14:43 ` Peter Zijlstra
2013-08-13 4:45 ` Lei Wen
2013-08-13 7:38 ` Peter Zijlstra [this message]
2013-08-13 8:08 ` Paul Turner
2013-08-13 8:18 ` Lei Wen
2013-08-13 9:25 ` Paul Turner
2013-08-18 9:12 ` Lei Wen
2013-08-15 17:39 ` Peter Zijlstra
2013-08-15 18:23 ` Paul Turner
2013-08-15 18:39 ` Peter Zijlstra
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