From: Li Zefan <lizefan-hv44wF8Li93QT0dZR+AlfA@public.gmane.org>
To: Viresh Kumar <viresh.kumar-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>
Cc: tglx-hfZtesqFncYOwBW4kG4KsQ@public.gmane.org,
fweisbec-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org,
peterz-wEGCiKHe2LqWVfeAwA7xHQ@public.gmane.org,
mingo-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org,
tj-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org,
linaro-kernel-cunTk1MwBs8s++Sfvej+rw@public.gmane.org,
linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
Subject: Re: [RFC 4/4] cpuset: Add cpusets.quiesce option
Date: Thu, 27 Mar 2014 10:47:47 +0800 [thread overview]
Message-ID: <53339153.70708@huawei.com> (raw)
In-Reply-To: <e643acf71086db239254d44c77d4966b2a4a01e5.1395322529.git.viresh.kumar-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>
On 2014/3/20 21:49, Viresh Kumar wrote:
> For networking applications platforms need to provide one CPU per each user
> space data plane thread. These CPUs should not be interrupted by kernel at all
> unless userspace has requested for some syscalls. Currently, there are
> background kernel activities that are running on almost every CPU, like:
> timers/hrtimers/watchdogs/etc, and these are required to be migrated to other
> CPUs.
>
> To achieve that, this patch adds another option to cpusets, i.e. 'quiesce'.
> Writing '1' on this file would migrate these unbound/unpinned timers/workqueues
> away from the CPUs of the cpuset in question. Writing '0' has no effect and this
> file can't be read from userspace as we aren't maintaining a state here.
>
This doesn't look like a complete solution, because newer timers/workqueues can
still run in those CPUs. Seems like the proposal discussed is to support setting
cpu affinity for workqueues through sysfs. If so, we can migrate workqueues when
affinity is set, so we don't need this cpuset.quiesce ?
> Currently, only timers are migrated. This would be followed by other kernel
> infrastructure later.
>
> Suggested-by: Peter Zijlstra <peterz-wEGCiKHe2LqWVfeAwA7xHQ@public.gmane.org>
> Signed-off-by: Viresh Kumar <viresh.kumar-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>
next prev parent reply other threads:[~2014-03-27 2:47 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-03-20 13:48 [RFC 0/4] Migrate timers away from cpuset on setting cpuset.quiesce Viresh Kumar
2014-03-20 13:48 ` [RFC 1/4] timer: track pinned timers with TIMER_PINNED flag Viresh Kumar
2014-03-20 13:48 ` [RFC 2/4] timer: don't migrate pinned timers Viresh Kumar
[not found] ` <3fa0ea3a19a51ae2797a25e281763451ad8d2844.1395322529.git.viresh.kumar-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>
2014-03-31 15:56 ` Kevin Hilman
[not found] ` <7htxae5plh.fsf-4poPxKt068f/PtFMR13I2A@public.gmane.org>
2014-04-01 4:32 ` Viresh Kumar
[not found] ` <CAKohpokYfdY+40kmhgrC6Yr9vfv4GtAW2Ph3+=57YbfmJsnU9w-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2014-04-04 15:15 ` Kevin Hilman
2014-03-20 13:49 ` [RFC 3/4] timer: create timer_quiesce_cpu() for cpusets.quiesce option Viresh Kumar
2014-03-20 13:49 ` [RFC 4/4] cpuset: Add " Viresh Kumar
[not found] ` <e643acf71086db239254d44c77d4966b2a4a01e5.1395322529.git.viresh.kumar-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>
2014-03-27 2:47 ` Li Zefan [this message]
[not found] ` <53339153.70708-hv44wF8Li93QT0dZR+AlfA@public.gmane.org>
2014-03-27 4:29 ` Viresh Kumar
[not found] ` <cover.1395322529.git.viresh.kumar-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>
2014-04-24 7:25 ` [RFC 0/4] Migrate timers away from cpuset on setting cpuset.quiesce Daniel Sangorrin
[not found] ` <201404240725.s3O7PrUv003720-g3qfMnKXm6lL9jVzuh4AOg@public.gmane.org>
2014-04-24 7:43 ` Viresh Kumar
[not found] ` <CAKohpokt-O3BAGMzE_=heVBZQOwp0C7eT8ZA2485DgNi3+Xcqg-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2014-04-24 8:31 ` Daniel Sangorrin
[not found] ` <201404240832.s3O8WHd0011014-g3qfMnKXm6lL9jVzuh4AOg@public.gmane.org>
2014-04-24 8:41 ` Viresh Kumar
2014-04-24 9:24 ` Daniel Sangorrin
2014-04-24 9:30 ` Viresh Kumar
[not found] ` <CAKohponA4-cm2_FB=8R8aVEWNhtUfOUebcfzn7W+XR0zKHCtxw-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2014-04-25 0:31 ` Daniel Sangorrin
[not found] ` <201404250031.s3P0V2DY022219-g3qfMnKXm6lL9jVzuh4AOg@public.gmane.org>
2014-04-25 4:51 ` Viresh Kumar
[not found] ` <CAKohpomQH01gCeUfqFFeHVNX7N7CSyo7zdj3LGBv9=U=cE46EA-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2014-04-25 5:21 ` Daniel Sangorrin
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