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From: Chris Redpath <chris.redpath@arm.com>
To: "bsegall@google.com" <bsegall@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>,
	"pjt@google.com" <pjt@google.com>,
	"mingo@redhat.com" <mingo@redhat.com>,
	"alex.shi@linaro.org" <alex.shi@linaro.org>,
	Morten Rasmussen <Morten.Rasmussen@arm.com>,
	Dietmar Eggemann <Dietmar.Eggemann@arm.com>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	Vincent Guittot <vincent.guittot@linaro.org>,
	Frederic Weisbecker <fweisbec@gmail.com>,
	Chris Redpath <Chris.Redpath@arm.com>
Subject: Re: [PATCH 2/2] sched: update runqueue clock before migrations away
Date: Wed, 18 Dec 2013 10:13:14 +0000	[thread overview]
Message-ID: <52B1753A.7060501@arm.com> (raw)
In-Reply-To: <xm26vbynmk2y.fsf@sword-of-the-dawn.mtv.corp.google.com>

On 17/12/13 18:03, bsegall@google.com wrote:
> __synchronize_entity_decay will decay load_avg_contrib in order to
> figure out how much to remove from old_cfs_rq->blocked_load.
> update_entity_load_avg will update the underlying runnable_avg_sum/period that
> is used to update load_avg_contrib.
>
> (Normally we update runnable_avg_sum, which updates load_avg_contrib via
> __update_entity_load_avg_contrib. Here we go in the reverse direction
> because we don't hold the right rq locks at the right times.)
>

Thanks Ben, got it now. The only question remaining for me to figure out 
is if I need to include the missed tick time in the contrib decay or not 
- I definitely need to include it in the negative decay count we send 
through a migration. I'll go and check the places we use the removed 
load and update blocked load again.


      reply	other threads:[~2013-12-18 10:13 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-12-09 12:59 [PATCH 0/2] Per-task load tracking errors Chris Redpath
2013-12-09 12:59 ` [PATCH 1/2] sched: reset blocked load decay_count during synchronization Chris Redpath
2013-12-09 17:59   ` bsegall
2013-12-09 12:59 ` [PATCH 2/2] sched: update runqueue clock before migrations away Chris Redpath
2013-12-09 18:13   ` bsegall
2013-12-10 11:48   ` Peter Zijlstra
2013-12-10 13:24     ` Chris Redpath
2013-12-10 15:14       ` Peter Zijlstra
2013-12-10 15:55         ` Chris Redpath
2013-12-12 18:24           ` Peter Zijlstra
2013-12-13  8:48             ` Vincent Guittot
2013-12-17 14:09             ` Chris Redpath
2013-12-17 15:51               ` Peter Zijlstra
2013-12-17 18:03               ` bsegall
2013-12-18 10:13                 ` Chris Redpath [this message]

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