[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <20070511232024.GA489@tv-sign.ru>
Date: Sat, 12 May 2007 03:20:24 +0400
From: Oleg Nesterov <oleg@...sign.ru>
To: Linus Torvalds <torvalds@...ux-foundation.org>
Cc: "Rafael J. Wysocki" <rjw@...k.pl>,
Andrew Morton <akpm@...ux-foundation.org>,
Gautham R Shenoy <ego@...ibm.com>,
LKML <linux-kernel@...r.kernel.org>, Pavel Machek <pavel@....cz>,
"Eric W. Biederman" <ebiederm@...ssion.com>
Subject: Re: [PATCH 1/7] Freezer: Read PF_BORROWED_MM in a nonracy way
On 05/11, Linus Torvalds wrote:
>
> On Fri, 11 May 2007, Rafael J. Wysocki wrote:
> >
> > Therefore, by taking the task_lock() here we make sure that the condition
> > is alyways false when we check it for kernel threads.
>
> Why *test* it then and return anything?
>
> Why not just doa "task_lock(p); task_unlock(p);" with no return value?
because we should not freeze a kernel thread at FREEZER_USER_SPACE stage?
without task_lock() we can see "p->mm != NULL" but not PF_BORROWED_MM.
Oleg.
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists