Re: [RFC] Restrict kernel spawning of threads to a specified set of cpus.

From: Gilad Ben-Yossef
Date: Tue Sep 10 2013 - 03:56:52 EST


On Tue, Sep 10, 2013 at 10:26 AM, Mike Galbraith <bitbucket@xxxxxxxxx> wrote:

>
> Hammering on the wrong spot makes removing isolcpus take longer, and
> adds up to more hammering in the long run, no? Hearing you mention
> isolcpus, I just thought I should mention that it wants to go away, so
> might not be the optimal spot for isolation related tinkering.


OK, so I'll bite - isolcpu currently has special magic to do its thing but AFAIK
part of the reason isolcpu works "better" (for some definition of
better, for some
work loads) is simply because it blocks migration earlier than you get with
cpusets.

What if we re-did the implementation of isolcpu as creating an
cpuset with migration off as early as possible in the boot process, prior to
spawning init?

So basically, isolcpus becomes just a way to configure a cpuset early?


Gilad



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Gilad Ben-Yossef
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