From: Tejun Heo <tj-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
To: Glauber Costa <glommer-GEFAQzZX7r8dnm+yROfE0A@public.gmane.org>
Cc: Peter Zijlstra
<a.p.zijlstra-/NLkJaSkS4VmR6Xm/wNWPw@public.gmane.org>,
Paul Turner <pjt-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>,
linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
Frederic Weisbecker
<fweisbec-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>,
devel-GEFAQzZX7r8dnm+yROfE0A@public.gmane.org
Subject: Re: [PATCH v7 08/11] sched: Push put_prev_task() into pick_next_task()
Date: Thu, 6 Jun 2013 16:56:47 -0700 [thread overview]
Message-ID: <20130606235647.GR5045@htj.dyndns.org> (raw)
In-Reply-To: <1369825402-31046-9-git-send-email-glommer-GEFAQzZX7r8dnm+yROfE0A@public.gmane.org>
On Wed, May 29, 2013 at 03:03:19PM +0400, Glauber Costa wrote:
> From: Peter Zijlstra <a.p.zijlstra-/NLkJaSkS4VmR6Xm/wNWPw@public.gmane.org>
>
> In order to avoid having to do put/set on a whole cgroup hierarchy
> when we context switch, push the put into pick_next_task() so that
> both operations are in the same function. Further changes then allow
> us to possibly optimize away redundant work.
I suppose this is to optimize out css_put/get() if the previous and
next tasks are in the same group? css refcnt will soon (this week) be
converted to percpu reference counter, so the optimization might not
be as meaningful unless there are other things which are being
optimized.
Thanks.
--
tejun
next prev parent reply other threads:[~2013-06-06 23:56 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-05-29 11:03 [PATCH v7 00/11] per-cgroup cpu-stat Glauber Costa
2013-05-29 11:03 ` [PATCH v7 04/11] sched: adjust exec_clock to use it as cpu usage metric Glauber Costa
[not found] ` <1369825402-31046-5-git-send-email-glommer-GEFAQzZX7r8dnm+yROfE0A@public.gmane.org>
2013-06-06 23:00 ` Tejun Heo
2013-05-29 11:03 ` [PATCH v7 09/11] sched: record per-cgroup number of context switches Glauber Costa
[not found] ` <1369825402-31046-10-git-send-email-glommer-GEFAQzZX7r8dnm+yROfE0A@public.gmane.org>
2013-06-07 0:04 ` Tejun Heo
[not found] ` <1369825402-31046-1-git-send-email-glommer-GEFAQzZX7r8dnm+yROfE0A@public.gmane.org>
2013-05-29 11:03 ` [PATCH v7 01/11] don't call cpuacct_charge in stop_task.c Glauber Costa
2013-05-29 11:03 ` [PATCH v7 02/11] cgroup: implement CFTYPE_NO_PREFIX Glauber Costa
2013-05-29 11:03 ` [PATCH v7 03/11] cgroup, sched: let cpu serve the same files as cpuacct Glauber Costa
2013-05-29 11:03 ` [PATCH v7 05/11] cpuacct: don't actually do anything Glauber Costa
[not found] ` <1369825402-31046-6-git-send-email-glommer-GEFAQzZX7r8dnm+yROfE0A@public.gmane.org>
2013-06-06 23:16 ` Tejun Heo
2013-05-29 11:03 ` [PATCH v7 06/11] sched: document the cpu cgroup Glauber Costa
2013-06-06 23:28 ` Tejun Heo
2013-05-29 11:03 ` [PATCH v7 07/11] sched: account guest time per-cgroup as well Glauber Costa
[not found] ` <1369825402-31046-8-git-send-email-glommer-GEFAQzZX7r8dnm+yROfE0A@public.gmane.org>
2013-06-06 23:48 ` Tejun Heo
2013-05-29 11:03 ` [PATCH v7 08/11] sched: Push put_prev_task() into pick_next_task() Glauber Costa
[not found] ` <1369825402-31046-9-git-send-email-glommer-GEFAQzZX7r8dnm+yROfE0A@public.gmane.org>
2013-06-06 23:56 ` Tejun Heo [this message]
2013-05-29 11:03 ` [PATCH v7 10/11] sched: change nr_context_switches calculation Glauber Costa
2013-05-29 11:03 ` [PATCH v7 11/11] sched: introduce cgroup file stat_percpu Glauber Costa
2013-06-06 1:49 ` [PATCH v7 00/11] per-cgroup cpu-stat Tejun Heo
[not found] ` <20130606014929.GS10693-9pTldWuhBndy/B6EtB590w@public.gmane.org>
2013-06-06 7:58 ` Glauber Costa
2013-06-07 0:06 ` Tejun Heo
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