From: Joonsoo Kim <iamjoonsoo.kim@lge.com>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Paul Turner <pjt@google.com>, Ingo Molnar <mingo@kernel.org>,
LKML <linux-kernel@vger.kernel.org>,
Mike Galbraith <efault@gmx.de>, Alex Shi <alex.shi@intel.com>,
Preeti U Murthy <preeti@linux.vnet.ibm.com>,
Vincent Guittot <vincent.guittot@linaro.org>,
Morten Rasmussen <morten.rasmussen@arm.com>,
Namhyung Kim <namhyung@kernel.org>, Lei Wen <leiwen@marvell.com>,
Rik van Riel <riel@surriel.com>
Subject: Re: [PATCH 02/10] sched: Factor out code to should_we_balance()
Date: Fri, 23 Aug 2013 13:51:54 +0900 [thread overview]
Message-ID: <20130823045154.GB22605@lge.com> (raw)
In-Reply-To: <20130822104257.GH31370@twins.programming.kicks-ass.net>
On Thu, Aug 22, 2013 at 12:42:57PM +0200, Peter Zijlstra wrote:
> > >
> > > +redo:
> >
> > One behavioral change worth noting here is that in the redo case if a
> > CPU has become idle we'll continue trying to load-balance in the
> > !new-idle case.
> >
> > This could be unpleasant in the case where a package has a pinned busy
> > core allowing this and a newly idle cpu to start dueling for load.
> >
> > While more deterministically bad in this case now, it could racily do
> > this before anyway so perhaps not worth worrying about immediately.
>
> Ah, because the old code would effectively redo the check and find the
> idle cpu and thereby our cpu would no longer be the balance_cpu.
>
> Indeed. And I don't think this was an intentional change. I'll go put
> the redo back before should_we_balance().
Ah, yes.
It isn't my intention. Please fix it.
Thanks.
next prev parent reply other threads:[~2013-08-23 4:51 UTC|newest]
Thread overview: 47+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-08-19 16:00 [PATCH 00/10] Various load-balance cleanups/optimizations -v2 Peter Zijlstra
2013-08-19 16:00 ` [PATCH 01/10] sched: Remove one division operation in find_busiest_queue() Peter Zijlstra
2013-08-22 8:58 ` Paul Turner
2013-08-22 10:25 ` Peter Zijlstra
2013-08-19 16:01 ` [PATCH 02/10] sched: Factor out code to should_we_balance() Peter Zijlstra
2013-08-22 9:58 ` Paul Turner
2013-08-22 10:42 ` Peter Zijlstra
2013-08-23 4:51 ` Joonsoo Kim [this message]
2013-08-23 11:37 ` Paul Turner
2013-08-19 16:01 ` [PATCH 03/10] sched: Clean-up struct sd_lb_stat Peter Zijlstra
2013-08-24 10:09 ` Paul Turner
2013-08-26 11:38 ` Peter Zijlstra
2013-08-26 2:56 ` Lei Wen
2013-08-26 4:36 ` Paul Turner
2013-08-26 8:42 ` Lei Wen
2013-08-19 16:01 ` [PATCH 04/10] sched, fair: Shrink sg_lb_stats and play memset games Peter Zijlstra
2013-08-21 2:08 ` Joonsoo Kim
2013-08-21 2:20 ` Joonsoo Kim
2013-08-21 8:38 ` Peter Zijlstra
2013-08-21 8:35 ` Peter Zijlstra
2013-08-24 10:15 ` Paul Turner
2013-08-26 11:46 ` Peter Zijlstra
2013-08-19 16:01 ` [PATCH 05/10] sched, fair: Remove duplicate load_per_task computations Peter Zijlstra
2013-08-19 16:01 ` [PATCH 06/10] sched, fair: Make group power more consitent Peter Zijlstra
2013-08-23 3:40 ` Preeti U Murthy
2013-08-19 16:01 ` [PATCH 07/10] sched, fair: Optimize find_busiest_queue() Peter Zijlstra
2013-08-23 8:11 ` Preeti U Murthy
2013-08-23 10:03 ` Peter Zijlstra
2013-08-23 10:54 ` Preeti U Murthy
2013-08-24 10:33 ` Paul Turner
2013-08-26 12:07 ` Peter Zijlstra
2013-08-27 9:13 ` Paul Turner
2013-08-19 16:01 ` [PATCH 08/10] sched, fair: Rework and comment the group_imb code Peter Zijlstra
2013-08-19 16:01 ` [PATCH 09/10] sched, fair: Fix the sd_parent_degenerate() code Peter Zijlstra
2013-08-24 10:45 ` Paul Turner
2013-08-26 12:09 ` Peter Zijlstra
2013-08-26 21:49 ` Rik van Riel
2013-08-27 9:05 ` Paul Turner
2013-08-19 16:01 ` [RFC][PATCH 10/10] sched, fair: Rewrite group_imb trigger Peter Zijlstra
2013-08-21 2:09 ` [PATCH 00/10] Various load-balance cleanups/optimizations -v2 Joonsoo Kim
2013-08-28 8:55 ` [RFC][PATCH 11/10] sched, fair: Reduce local_group logic Peter Zijlstra
2013-08-28 8:57 ` Peter Zijlstra
2013-08-28 9:16 ` Peter Zijlstra
2013-08-28 11:14 ` [PATCH 12/10] sched, fair: Fix group power_orig computation Peter Zijlstra
2013-08-28 11:15 ` [PATCH 13/10] sched, fair: Rework and comment the group_capacity code Peter Zijlstra
2013-08-28 11:16 ` [RFC][PATCH 14/10] sched, fair: Fix the group_capacity computation Peter Zijlstra
2013-09-04 7:44 ` Vincent Guittot
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