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From: Rik van Riel <riel@redhat.com>
To: tj@kernel.org
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: Wed, 18 Mar 2015 12:13:36 -0400	[thread overview]
Message-ID: <5509A430.9040005@redhat.com> (raw)
In-Reply-To: <1425917530-1771-1-git-send-email-riel@redhat.com>

On 03/09/2015 12:12 PM, 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.

Ping?

Tejun? Li?


  parent reply	other threads:[~2015-03-18 16:13 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 ` Rik van Riel [this message]
2015-03-19 18:30 ` [PATCH v4 RESEND 0/4] cpusets,isolcpus: exclude isolcpus from load balancing in cpusets Tejun Heo

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