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From: Tejun Heo <tj@kernel.org>
To: riel@redhat.com
Cc: linux-kernel@vger.kernel.org, cgroups@vger.kernel.org,
	lizefan@huawei.com
Subject: Re: [PATCH v4 RESEND 0/4] cpusets,isolcpus: exclude isolcpus from load balancing in cpusets
Date: Thu, 19 Mar 2015 14:30:01 -0400	[thread overview]
Message-ID: <20150319183001.GD19657@htj.duckdns.org> (raw)
In-Reply-To: <1425917530-1771-1-git-send-email-riel@redhat.com>

On Mon, Mar 09, 2015 at 12:12:06PM -0400, 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.
> 
> This version fixes the UP compilation issue, in the same way done
> for the other cpumasks.

Applied 1, 2, and 4 to cgroup/for-4.1.  I collected the acks from the
previous threads.  Can you please collect them when posting new
revisions in the future?

Thanks.

-- 
tejun

      parent reply	other threads:[~2015-03-19 18:30 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-03-09 16:12 riel
2015-03-09 16:12 ` [PATCH 1/4] sched,isolcpu: make cpu_isolated_map visible outside scheduler riel
2015-03-09 16:12 ` [PATCH 2/4] cpusets,isolcpus: exclude isolcpus from load balancing in cpusets riel
2015-03-09 16:12 ` [PATCH 3/4] cpusets,isolcpus: add file to show isolated cpus in cpuset riel
2015-03-18 16:47   ` Tejun Heo
2015-03-18 23:40     ` Rik van Riel
2015-03-19  1:50       ` Zefan Li
2015-03-19  1:54         ` Rik van Riel
2015-03-19  6:28           ` Zefan Li
2015-03-19  1:45     ` Rik van Riel
2015-03-19  1:48       ` Tejun Heo
2015-03-09 16:12 ` [PATCH 4/4] cpuset,isolcpus: document relationship between cpusets & isolcpus riel
2015-03-18 16:13 ` [PATCH v4 RESEND 0/4] cpusets,isolcpus: exclude isolcpus from load balancing in cpusets Rik van Riel
2015-03-19 18:30 ` Tejun Heo [this message]

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