All of lore.kernel.org
 help / color / mirror / Atom feed
From: Tejun Heo <tj@kernel.org>
To: Frederic Weisbecker <fweisbec@gmail.com>
Cc: tip-bot for Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>,
	linux-tip-commits@vger.kernel.org, linux-kernel@vger.kernel.org,
	hpa@zytor.com, mingo@redhat.com, a.p.zijlstra@chello.nl,
	pjt@google.com, tglx@linutronix.de, mingo@elte.hu
Subject: Re: [tip:sched/core] sched: Fix cgroup movement of forking process
Date: Wed, 21 Dec 2011 18:01:57 -0800	[thread overview]
Message-ID: <20111222020157.GR9213@google.com> (raw)
In-Reply-To: <20111222015440.GM17668@somewhere>

Hello,

On Thu, Dec 22, 2011 at 02:54:42AM +0100, Frederic Weisbecker wrote:
> > Frederic, so, it seems we actually have race conditions here.  I
> > really wish cgroup made sure that things like this can't happen even
> > if we pay a bit of overhead in relatively cold paths.  I could be
> > being unrealistic tho.  Any ideas?
> 
> Hmm, I'm a bit confused about the issue. But doesn't this patch fix the issue?

Yeah, I was just saying it would be nice if we don't have to fix the
issue.

> Also the parent can't be calling sched_fork() and cgroup_exit() at
> the same time.

Hmmm... so this one can't happen anymore but there are races involving
cgroup_exit() which doesn't have anything to do with threadgroup lock
(Dalsuke has more patches), so this doesn't really matter.  Let's
forget about this thread.

Thanks.

-- 
tejun

  reply	other threads:[~2011-12-22  2:02 UTC|newest]

Thread overview: 35+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-12-13  6:57 [PATCH 0/3] sched: some fixes for vruntime calculation related to cgroup movement Daisuke Nishimura
2011-12-13  6:57 ` Daisuke Nishimura
2011-12-13  6:57 ` [PATCH 1/3] sched: fix cgroup movement of newly created process Daisuke Nishimura
2011-12-13  6:57   ` Daisuke Nishimura
2011-12-13 12:01   ` Paul Turner
2011-12-13 12:01     ` Paul Turner
2011-12-14  1:04     ` Daisuke Nishimura
2011-12-14  1:04       ` Daisuke Nishimura
2011-12-13 12:41   ` Peter Zijlstra
2011-12-13 12:41     ` Peter Zijlstra
2011-12-14  1:05     ` Daisuke Nishimura
2011-12-14  1:05       ` Daisuke Nishimura
2011-12-13  6:58 ` [PATCH 2/3] sched: fix cgroup movement of forking process Daisuke Nishimura
2011-12-13  6:58   ` Daisuke Nishimura
2011-12-13 12:22   ` Paul Turner
2011-12-13 12:22     ` Paul Turner
2011-12-13  6:59 ` [PATCH 3/3] sched: fix cgroup movement of waking process Daisuke Nishimura
2011-12-13  6:59   ` Daisuke Nishimura
2011-12-13 12:24   ` Paul Turner
2011-12-13 12:24     ` Paul Turner
2011-12-15  5:35 ` [PATCH -tip 0/3] sched: some fixes for vruntime calculation related to cgroup movement(v2) Daisuke Nishimura
2011-12-15  5:36   ` [PATCH 1/3] sched: fix cgroup movement of newly created process Daisuke Nishimura
2011-12-15  5:36     ` Daisuke Nishimura
2011-12-21 11:45     ` [tip:sched/core] sched: Fix " tip-bot for Daisuke Nishimura
2011-12-15  5:36   ` [PATCH 2/3] sched: fix cgroup movement of forking process Daisuke Nishimura
2011-12-15  5:36     ` Daisuke Nishimura
2011-12-21 11:44     ` [tip:sched/core] sched: Fix " tip-bot for Daisuke Nishimura
2011-12-21 17:26       ` Tejun Heo
2011-12-21 17:37         ` Tejun Heo
2011-12-22  1:54           ` Frederic Weisbecker
2011-12-22  2:01             ` Tejun Heo [this message]
2011-12-15  5:37   ` [PATCH 3/3] sched: fix cgroup movement of waking process Daisuke Nishimura
2011-12-21 11:45     ` [tip:sched/core] sched: Fix " tip-bot for Daisuke Nishimura
2011-12-19  2:55   ` [PATCH -tip 0/3] sched: some fixes for vruntime calculation related to cgroup movement(v2) Daisuke Nishimura
2011-12-19  2:55     ` Daisuke Nishimura

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20111222020157.GR9213@google.com \
    --to=tj@kernel.org \
    --cc=a.p.zijlstra@chello.nl \
    --cc=fweisbec@gmail.com \
    --cc=hpa@zytor.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-tip-commits@vger.kernel.org \
    --cc=mingo@elte.hu \
    --cc=mingo@redhat.com \
    --cc=nishimura@mxp.nes.nec.co.jp \
    --cc=pjt@google.com \
    --cc=tglx@linutronix.de \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.