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Date: Fri, 09 May 2014 12:50:28 -0700
From: Peter Grehan <grehan@freebsd.org>
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To: Adrian Chadd <adrian@freebsd.org>, John Baldwin <jhb@freebsd.org>
Subject: Re: [rfc] bind per-cpu timeout threads to each CPU
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Cc: Alexander Motin <mav@freebsd.org>,
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> How about i instead do the comprimise:
>
> * i'll pin all other swi's
> * default swi isn't pinned by default, but one can flip on a sysctl at
> boot time to pin it
>
> How's that sound?

  And also please a sysctl that disables any swi pinning.

  It is sometimes useful to change the default cpuset, for instance to 
allocate a subset of CPUs to some particular applications and not 
FreeBSD. Having kernel threads pinned prevents this from happening since 
they are in the default set.

  (Note that some network drivers are also culprits here, though 
disabling MSI-x in them is a workaround).

later,

Peter.