From: Oleg Nesterov <oleg@redhat.com>
To: Colin Cross <ccross@android.com>
Cc: linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org,
"Rafael J. Wysocki" <rjw@sisk.pl>,
arve@android.com, Tejun Heo <tj@kernel.org>,
Li Zefan <lizefan@huawei.com>, Len Brown <len.brown@intel.com>,
Pavel Machek <pavel@ucw.cz>,
containers@redhat.com
Subject: Re: [PATCH 02/10] freezer: skip waking up tasks with PF_FREEZER_SKIP set
Date: Tue, 30 Apr 2013 19:10:59 +0200 [thread overview]
Message-ID: <20130430171059.GA28944@redhat.com> (raw)
In-Reply-To: <1367271946-7239-3-git-send-email-ccross@android.com>
On 04/29, Colin Cross wrote:
>
> @@ -46,10 +46,10 @@ static int try_to_freeze_tasks(bool user_only)
> todo = 0;
> read_lock(&tasklist_lock);
> do_each_thread(g, p) {
> - if (p == current || !freeze_task(p))
> + if (p == current || freezer_should_skip(p))
> continue;
>
> - if (!freezer_should_skip(p))
> + if (freeze_task(p))
> todo++;
What if we race with freezer_count() ?
try_to_freeze_tasks() can wrongly succeed leaving the running task
unfrozen, no?
Oleg.
next prev parent reply other threads:[~2013-04-30 17:14 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-04-29 21:45 [PATCH 00/10] optimize freezing tasks by reducing task wakeups Colin Cross
2013-04-29 21:45 ` [PATCH 01/10] freezer: shorten freezer sleep time using exponential backoff Colin Cross
2013-05-02 12:28 ` Pavel Machek
[not found] ` <1367271946-7239-1-git-send-email-ccross-z5hGa2qSFaRBDgjK7y7TUQ@public.gmane.org>
2013-04-29 21:45 ` [PATCH 02/10] freezer: skip waking up tasks with PF_FREEZER_SKIP set Colin Cross
[not found] ` <1367271946-7239-3-git-send-email-ccross-z5hGa2qSFaRBDgjK7y7TUQ@public.gmane.org>
2013-04-29 21:51 ` Tejun Heo
[not found] ` <20130429215157.GA2395-Gd/HAXX7CRxy/B6EtB590w@public.gmane.org>
2013-04-29 21:57 ` Tejun Heo
2013-04-29 22:02 ` Colin Cross
[not found] ` <CAMbhsRQHkm=XTYtummEZq1h4sa-tRGwLpk8Uyhpj9D3+jQF3dg-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2013-04-29 22:08 ` Tejun Heo
[not found] ` <20130429220831.GC2395-Gd/HAXX7CRxy/B6EtB590w@public.gmane.org>
2013-04-29 22:16 ` Tejun Heo
2013-04-30 11:48 ` Rafael J. Wysocki
2013-04-30 17:10 ` Oleg Nesterov [this message]
2013-04-30 17:15 ` Oleg Nesterov
2013-04-29 21:45 ` [PATCH 03/10] freezer: add new freezable helpers using freezer_do_not_count() Colin Cross
2013-05-02 12:48 ` Pavel Machek
2013-05-02 13:05 ` Oliver Neukum
2013-05-02 13:46 ` Pavel Machek
2013-05-02 17:05 ` Colin Cross
2013-05-03 14:00 ` Pavel Machek
2013-04-29 21:45 ` [PATCH 04/10] binder: use freezable blocking calls Colin Cross
2013-04-29 21:45 ` [PATCH 05/10] epoll: use freezable blocking call Colin Cross
2013-04-29 21:45 ` [PATCH 06/10] select: " Colin Cross
2013-04-29 21:45 ` [PATCH 07/10] futex: " Colin Cross
2013-04-29 22:52 ` Darren Hart
2013-04-29 23:46 ` Colin Cross
2013-05-02 19:52 ` Matt Helsley
2013-04-29 21:45 ` [PATCH 08/10] nanosleep: " Colin Cross
2013-04-29 21:45 ` [PATCH 09/10] sigtimedwait: " Colin Cross
2013-04-30 16:38 ` Oleg Nesterov
2013-04-30 16:56 ` Oleg Nesterov
2013-04-30 16:58 ` Colin Cross
2013-04-30 17:00 ` Oleg Nesterov
2013-04-29 21:45 ` [PATCH 10/10] af_unix: use freezable blocking calls in read Colin Cross
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