From: Andrew Morton <akpm@linux-foundation.org>
To: Glauber Costa <glommer@parallels.com>
Cc: cgroups@vger.kernel.org, linux-kernel@vger.kernel.org,
Tejun Heo <tj@kernel.org>,
Peter Zijlstra <a.p.zijlstra@chello.nl>,
Paul Turner <pjt@google.com>
Subject: Re: [PATCH v5 11/11] sched: introduce cgroup file stat_percpu
Date: Wed, 9 Jan 2013 13:17:05 -0800 [thread overview]
Message-ID: <20130109131705.4156ba5c.akpm@linux-foundation.org> (raw)
In-Reply-To: <50EDDCAA.6070004@parallels.com>
On Thu, 10 Jan 2013 01:10:02 +0400
Glauber Costa <glommer@parallels.com> wrote:
> The main advantage I see in this approach, is that there is way less
> data to be written using a header. Although your way works, it means we
> will write the strings "nice", "system", etc. #cpu times. Quite a waste.
Yes, overhead can be a significant issue with this type of interface.
But we already incurred a massive overhead by using a human-readable
ascii interface. If performance is an issue, perhaps the whole thing
should be grafted onto taskstats instead. Or create a new
taskstats-like thing.
btw, a more typical interface would be
cat /.../cpu0
nice:nn
system:nn
irq:nn
- the traditional one-per-line name:value tuples. But I'd assumed that
having a file per CPU would be aawkward.
next prev parent reply other threads:[~2013-01-09 21:17 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-01-09 11:45 [PATCH v5 00/11] per-cgroup cpu-stat Glauber Costa
2013-01-09 11:45 ` [PATCH v5 01/11] don't call cpuacct_charge in stop_task.c Glauber Costa
2013-01-09 11:45 ` [PATCH v5 02/11] cgroup: implement CFTYPE_NO_PREFIX Glauber Costa
2013-01-09 11:45 ` [PATCH v5 04/11] cgroup, sched: deprecate cpuacct Glauber Costa
2013-01-09 11:45 ` [PATCH v5 05/11] sched: adjust exec_clock to use it as cpu usage metric Glauber Costa
2013-01-09 11:45 ` [PATCH v5 06/11] cpuacct: don't actually do anything Glauber Costa
2013-01-09 11:45 ` [PATCH v5 07/11] account guest time per-cgroup as well Glauber Costa
2013-01-09 11:45 ` [PATCH v5 09/11] record per-cgroup number of context switches Glauber Costa
2013-01-09 11:45 ` [PATCH v5 10/11] sched: change nr_context_switches calculation Glauber Costa
[not found] ` <1357731938-8417-1-git-send-email-glommer-bzQdu9zFT3WakBO8gow8eQ@public.gmane.org>
2013-01-09 11:45 ` [PATCH v5 03/11] cgroup, sched: let cpu serve the same files as cpuacct Glauber Costa
[not found] ` <1357731938-8417-4-git-send-email-glommer-bzQdu9zFT3WakBO8gow8eQ@public.gmane.org>
2013-01-14 8:34 ` Sha Zhengju
[not found] ` <CAFj3OHW5J8ypLZdW16AfiYR5y2S54mQxm5qka4m_3qsoGdD11A-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2013-01-14 14:55 ` Glauber Costa
[not found] ` <50F41C50.6090000-bzQdu9zFT3WakBO8gow8eQ@public.gmane.org>
2013-01-15 10:19 ` Sha Zhengju
[not found] ` <CAFj3OHWB8GF9UYcLdObptrY+BfB=EEwbBtsf17M1=6qfZt+k6g-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2013-01-15 17:52 ` Glauber Costa
2013-01-09 11:45 ` [PATCH v5 08/11] sched: Push put_prev_task() into pick_next_task() Glauber Costa
2013-01-09 11:45 ` [PATCH v5 11/11] sched: introduce cgroup file stat_percpu Glauber Costa
[not found] ` <1357731938-8417-12-git-send-email-glommer-bzQdu9zFT3WakBO8gow8eQ@public.gmane.org>
2013-01-09 20:42 ` Andrew Morton
2013-01-09 21:10 ` Glauber Costa
2013-01-09 21:17 ` Andrew Morton [this message]
2013-01-09 21:27 ` Glauber Costa
[not found] ` <50EDE0AB.1030509-bzQdu9zFT3WakBO8gow8eQ@public.gmane.org>
2013-01-23 14:26 ` Glauber Costa
[not found] ` <20130109124220.ad9f1a54.akpm-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org>
2013-01-23 14:20 ` Glauber Costa
2013-01-09 14:41 ` [PATCH v5 00/11] per-cgroup cpu-stat Tejun Heo
2013-01-16 0:33 ` Colin Cross
2013-01-21 12:14 ` Glauber Costa
[not found] ` <50FD3123.6090003-bzQdu9zFT3WakBO8gow8eQ@public.gmane.org>
2013-01-23 1:02 ` Tejun Heo
[not found] ` <20130123010226.GF5359-Gd/HAXX7CRxy/B6EtB590w@public.gmane.org>
2013-01-23 1:53 ` Colin Cross
[not found] ` <CAMbhsRSDbKUz7OT3Y0bGfYqgp3yMgwk8oHx0rpsX+XDFWTMqkw-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2013-01-23 8:12 ` Glauber Costa
2013-01-23 16:56 ` Tejun Heo
2013-01-23 22:41 ` Colin Cross
[not found] ` <CAMbhsRRj9svWubn01wb+f=jSwVWC5u7DqJ5c8P23vAp0E2L8Rg-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2013-01-23 23:06 ` Tejun Heo
[not found] ` <20130123230608.GJ2373-9pTldWuhBndy/B6EtB590w@public.gmane.org>
2013-01-23 23:53 ` Colin Cross
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