From: Subhra Mazumdar <subhra.mazumdar@oracle.com>
To: Peter Zijlstra <peterz@infradead.org>
Cc: linux-kernel@vger.kernel.org, mingo@redhat.com,
daniel.lezcano@linaro.org, steven.sistare@oracle.com,
dhaval.giani@oracle.com, rohit.k.jain@oracle.com
Subject: Re: [PATCH 3/3] sched: limit cpu search and rotate search window for scalability
Date: Tue, 24 Apr 2018 15:48:41 -0700 [thread overview]
Message-ID: <bdea99d5-a0cd-1f60-e58a-0cc8e4dd6318@oracle.com> (raw)
In-Reply-To: <20180424124855.GT4082@hirez.programming.kicks-ass.net>
On 04/24/2018 05:48 AM, Peter Zijlstra wrote:
> On Mon, Apr 23, 2018 at 05:41:16PM -0700, subhra mazumdar wrote:
>> Lower the lower limit of idle cpu search in select_idle_cpu() and also put
>> an upper limit. This helps in scalability of the search by restricting the
>> search window. Also rotating the search window with help of next_cpu
>> ensures any idle cpu is eventually found in case of high load.
> So this patch does 2 (possibly 3) things, that's not good.
During testing I did try with first only restricting the search window.
That alone wasn't enough to give the full benefit, rotating search window
was essential to get best results. I will break this up in next version.
next prev parent reply other threads:[~2018-04-24 22:46 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-04-24 0:41 [RFC/RFT PATCH 0/3] Improve scheduler scalability for fast path subhra mazumdar
2018-04-24 0:41 ` [PATCH 1/3] sched: remove select_idle_core() for scalability subhra mazumdar
2018-04-24 12:46 ` Peter Zijlstra
2018-04-24 21:45 ` Subhra Mazumdar
2018-04-25 17:49 ` Peter Zijlstra
2018-04-30 23:38 ` Subhra Mazumdar
2018-05-01 18:03 ` Peter Zijlstra
2018-05-02 21:58 ` Subhra Mazumdar
2018-05-04 18:51 ` Subhra Mazumdar
2018-05-29 21:36 ` Peter Zijlstra
2018-05-30 22:08 ` Subhra Mazumdar
2018-05-31 9:26 ` Peter Zijlstra
2018-04-24 0:41 ` [PATCH 2/3] sched: introduce per-cpu var next_cpu to track search limit subhra mazumdar
2018-04-24 12:47 ` Peter Zijlstra
2018-04-24 22:39 ` Subhra Mazumdar
2018-04-24 0:41 ` [PATCH 3/3] sched: limit cpu search and rotate search window for scalability subhra mazumdar
2018-04-24 12:48 ` Peter Zijlstra
2018-04-24 22:43 ` Subhra Mazumdar
2018-04-24 12:48 ` Peter Zijlstra
2018-04-24 22:48 ` Subhra Mazumdar [this message]
2018-04-24 12:53 ` Peter Zijlstra
2018-04-25 0:10 ` Subhra Mazumdar
2018-04-25 15:36 ` Peter Zijlstra
2018-04-25 18:01 ` Peter Zijlstra
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