From: Mike Galbraith <umgwanakikbuti@gmail.com>
To: Yuyang Du <yuyang.du@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>,
Rabin Vincent <rabin.vincent@axis.com>,
"mingo@redhat.com" <mingo@redhat.com>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
Paul Turner <pjt@google.com>, Ben Segall <bsegall@google.com>,
Morten Rasmussen <morten.rasmussen@arm.com>
Subject: Re: [PATCH?] Livelock in pick_next_task_fair() / idle_balance()
Date: Thu, 02 Jul 2015 10:05:47 +0200 [thread overview]
Message-ID: <1435824347.5351.18.camel@gmail.com> (raw)
In-Reply-To: <20150701232511.GA5197@intel.com>
On Thu, 2015-07-02 at 07:25 +0800, Yuyang Du wrote:
> That being said, it is also obvious to prevent the livelock from happening:
> idle pulling until the source rq's nr_running is 1, becuase otherwise we
> just avoid idleness by making another idleness.
Yeah, but that's just the symptom, not the disease. Better for the idle
balance symptom may actually be to only pull one when idle balancing.
After all, the immediate goal is to find something better to do than
idle, not to achieve continual perfect (is the enemy of good) balance.
-Mike
next prev parent reply other threads:[~2015-07-02 8:06 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-06-30 14:30 [PATCH?] Livelock in pick_next_task_fair() / idle_balance() Rabin Vincent
2015-07-01 5:36 ` Mike Galbraith
2015-07-01 14:55 ` Rabin Vincent
2015-07-01 15:47 ` Mike Galbraith
2015-07-01 20:44 ` Peter Zijlstra
2015-07-01 23:25 ` Yuyang Du
2015-07-02 8:05 ` Mike Galbraith [this message]
2015-07-02 1:05 ` Yuyang Du
2015-07-02 10:25 ` Mike Galbraith
2015-07-02 11:40 ` Morten Rasmussen
2015-07-02 19:37 ` Yuyang Du
2015-07-03 9:34 ` Morten Rasmussen
2015-07-03 16:38 ` Peter Zijlstra
2015-07-05 22:31 ` Yuyang Du
2015-07-09 14:32 ` Morten Rasmussen
2015-07-09 23:24 ` Yuyang Du
2015-07-05 20:12 ` Yuyang Du
2015-07-06 17:36 ` Dietmar Eggemann
2015-07-07 11:17 ` Rabin Vincent
2015-07-13 17:43 ` Dietmar Eggemann
2015-07-09 13:53 ` Morten Rasmussen
2015-07-09 22:34 ` Yuyang Du
2015-07-02 10:53 ` Peter Zijlstra
2015-07-02 11:44 ` Morten Rasmussen
2015-07-02 18:42 ` Yuyang Du
2015-07-03 4:42 ` Mike Galbraith
2015-07-03 16:39 ` Peter Zijlstra
2015-07-05 22:11 ` Yuyang Du
2015-07-09 6:15 ` Stefan Ekenberg
2015-07-26 18:57 ` Yuyang Du
2015-08-03 17:05 ` [tip:sched/core] sched/fair: Avoid pulling all tasks in idle balancing tip-bot for Yuyang Du
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