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From: Mike Galbraith <umgwanakikbuti@gmail.com>
To: riel@redhat.com
Cc: linux-kernel@vger.kernel.org
Subject: Re: [PATCH 0/2] cpusets,isolcpus: resolve conflict between cpusets and isolcpus
Date: Tue, 24 Feb 2015 03:18:46 +0100	[thread overview]
Message-ID: <1424744326.10678.4.camel@gmail.com> (raw)
In-Reply-To: <1424727906-4460-1-git-send-email-riel@redhat.com>

On Mon, 2015-02-23 at 16:45 -0500, riel@redhat.com wrote:
> Ensure that cpus specified with the isolcpus= boot commandline
> option stay outside of the load balancing in the kernel scheduler.
> 
> Operations like load balancing can introduce unwanted latencies,
> which is exactly what the isolcpus= commandline is there to prevent.
> 
> Previously, simply creating a new cpuset, without even touching the
> cpuset.cpus field inside the new cpuset, would undo the effects of
> isolcpus=, by creating a scheduler domain spanning the whole system,
> and setting up load balancing inside that domain. The cpuset root
> cpuset.cpus file is read-only, so there was not even a way to undo
> that effect.
> 
> This does not impact the majority of cpusets users, since isolcpus=
> is a fairly specialized feature used for realtime purposes.

3/3: nohz_full cpus become part of that unified isolated map?

	-Mike


  parent reply	other threads:[~2015-02-24  2:18 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-02-23 21:45 [PATCH 0/2] cpusets,isolcpus: resolve conflict between cpusets and isolcpus riel
2015-02-23 21:45 ` [PATCH 1/2] cpusets,isolcpus: exclude isolcpus from load balancing in cpusets riel
2015-02-25  2:10   ` David Rientjes
2015-02-23 21:45 ` [PATCH 2/2] cpusets,isolcpus: add file to show isolated cpus in cpuset riel
2015-02-25  2:15   ` David Rientjes
2015-02-25  3:30     ` Rik van Riel
2015-02-24  2:18 ` Mike Galbraith [this message]
2015-02-24 14:13   ` [PATCH 0/2] cpusets,isolcpus: resolve conflict between cpusets and isolcpus Rik van Riel
2015-02-24 14:22     ` Mike Galbraith
2015-02-24 14:29     ` Mike Galbraith

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