From: Peter Zijlstra <peterz@infradead.org>
To: Rohit Jain <rohit.k.jain@oracle.com>
Cc: linux-kernel@vger.kernel.org, mingo@redhat.com,
vincent.guittot@linaro.org, morten.rasmussen@arm.com,
dietmar.eggemann@arm.com
Subject: Re: [PATCH] sched: Introduce scaled capacity awareness in enqueue
Date: Tue, 30 May 2017 14:28:31 +0200 [thread overview]
Message-ID: <20170530122831.5fyywtplq4jawj3j@hirez.programming.kicks-ass.net> (raw)
In-Reply-To: <1495486094-9097-1-git-send-email-rohit.k.jain@oracle.com>
On Mon, May 22, 2017 at 01:48:14PM -0700, Rohit Jain wrote:
> The patch introduces capacity awarness in scheduler (CAS) which avoids
> CPUs which might have their capacities reduced (due to IRQ/RT activity)
> when trying to schedule threads (on the push side) in the system. This
> awareness has been added into the fair scheduling class.
>
> It does so by, using the following algorithm:
> --------------------------------------------------------------------------
> 1) As in rt_avg the scaled capacities are already calculated.
>
> 2) This scaled capacity is normalized and mapped into buckets.
Why?
> 3) Any CPU which lies below the 80th percentile in terms of percentage
> capacity available is considered as a low capacity CPU.
Random number; can we do better? What does existing code do?
next prev parent reply other threads:[~2017-05-30 12:28 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-05-22 20:48 Rohit Jain
2017-05-30 12:28 ` Peter Zijlstra [this message]
2017-05-31 22:19 ` Rohit Jain
2017-06-01 12:28 ` Peter Zijlstra
2017-06-01 12:37 ` Peter Zijlstra
2017-06-02 18:20 ` Rohit Jain
2017-06-02 18:26 ` Peter Zijlstra
2017-06-05 18:08 ` Rohit Jain
2017-06-12 15:36 ` Peter Zijlstra
2017-06-13 0:31 ` Rohit Jain
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