Date: Fri, 9 May 2014 16:51:49 -0400 From: John Baldwin <jhb@freebsd.org> To: Peter Grehan <grehan@freebsd.org> Cc: Adrian Chadd <adrian@freebsd.org>, freebsd-current <freebsd-current@freebsd.org>, Alexander Motin <mav@freebsd.org>, "freebsd-arch@freebsd.org" <freebsd-arch@freebsd.org> Subject: Re: [rfc] bind per-cpu timeout threads to each CPU Message-ID: <201405091651.49818.jhb@freebsd.org> In-Reply-To: <536D3184.9070302@freebsd.org> References: <530508B7.7060102@FreeBSD.org> <CAJ-VmokL40MGY2=sKAtvgMBKHt6ZRY9ZfnZ1Mj5y1qAa4ANC=A@mail.gmail.com> <536D3184.9070302@freebsd.org>
next in thread | previous in thread | raw e-mail | index | archive | help
On Friday, May 09, 2014 3:50:28 pm Peter Grehan wrote: > > 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). I'd actually like a way to exempt certain kernel threads that are inherently per-CPU (such as queues for NIC drivers or per-CPU swi threads) from the default cpuset so that they don't break 'cpuset -l 0 -s 1'. Providing some sort of way to disable the pinning for now should be good, but I think I'd eventually prefer the former suggestion. -- John Baldwin
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?201405091651.49818.jhb>