From: Peter Zijlstra <a.p.zijlstra@chello.nl>
To: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Suresh Siddha <suresh.b.siddha@intel.com>,
Alex Shi <alex.shi@intel.com>, Ying <ying.huang@intel.com>,
linux-kernel <linux-kernel@vger.kernel.org>
Subject: Re: load balancing regression since commit 367456c7
Date: Tue, 17 Apr 2012 14:09:13 +0200 [thread overview]
Message-ID: <1334664553.28150.87.camel@twins> (raw)
In-Reply-To: <1334106376.19157.89.camel@schen9-DESK>
On Tue, 2012-04-10 at 18:06 -0700, Tim Chen wrote:
> |--56.52%-- load_balance
> | idle_balance
> | __schedule
> | schedule
Ahh, I know why I didn't see it, I have a CONFIG_PREEMPT kernel and
idle_balancing stops once its gotten a single task over instead of
achieving proper balance.
And since hackbench generates insanely long runqueues and the patch that
caused your regression 'fixed' the lock-breaking it will now iterate the
entire runqueue if needed to achieve balance, which hurts.
I think the patch I send ought to work, let me try disabling
CONFIG_PREEMPT.
next prev parent reply other threads:[~2012-04-17 12:09 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-04-11 1:06 Tim Chen
2012-04-17 11:43 ` Peter Zijlstra
2012-04-17 12:09 ` Peter Zijlstra [this message]
2012-04-17 16:44 ` Tim Chen
2012-04-20 14:00 ` Peter Zijlstra
2012-04-20 16:40 ` Tim Chen
2012-04-20 16:53 ` Peter Zijlstra
2012-04-20 17:13 ` Tim Chen
2012-04-20 17:33 ` Peter Zijlstra
2012-04-25 14:56 ` Peter Zijlstra
2012-04-25 17:38 ` Tim Chen
2012-04-25 17:43 ` Peter Zijlstra
2012-04-25 17:58 ` Tim Chen
2012-04-26 11:56 ` [tip:sched/urgent] sched: Fix more load-balancing fallout tip-bot for Peter Zijlstra
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