From: Andrew Morton <akpm@linux-foundation.org>
To: Dimitri Sivanich <sivanich@sgi.com>
Cc: linux-kernel@vger.kernel.org, Thomas Gleixner <tglx@linutronix.de>
Subject: Re: [PATCH] specific do_timer_cpu value for nohz off mode
Date: Wed, 30 Nov 2011 18:13:18 -0800 [thread overview]
Message-ID: <20111130181318.38f4659d.akpm@linux-foundation.org> (raw)
In-Reply-To: <20111201020727.GB30097@sgi.com>
On Wed, 30 Nov 2011 20:07:27 -0600 Dimitri Sivanich <sivanich@sgi.com> wrote:
> > And the whole thing is racy, isn't it? The "new" CPU can go offline a
> > nanosecond after we performed that test, so why perform it at all?
>
> See my email concerning the panic in cpu_online().
That doesn't address my question.
What's the point in checking cpu_online() when we have no locks to
prevent the online map from changing?
What happens if this cpu goes offline immediately after that check has
passed?
next prev parent reply other threads:[~2011-12-01 2:12 UTC|newest]
Thread overview: 35+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-11-08 19:11 Dimitri Sivanich
2011-11-23 0:08 ` Andrew Morton
2011-11-30 15:29 ` Dimitri Sivanich
2011-12-01 0:11 ` Andrew Morton
2011-12-01 0:16 ` Andrew Morton
2011-12-01 2:07 ` Dimitri Sivanich
2011-12-01 2:13 ` Andrew Morton [this message]
2011-12-01 16:37 ` Dimitri Sivanich
2011-12-01 22:56 ` Andrew Morton
2011-12-02 20:14 ` Dimitri Sivanich
2011-12-02 20:22 ` Dimitri Sivanich
2011-12-02 22:42 ` Thomas Gleixner
2011-12-01 2:06 ` Dimitri Sivanich
2011-12-01 2:12 ` Andrew Morton
2011-12-01 2:34 ` Dimitri Sivanich
2011-12-01 2:38 ` Andrew Morton
2012-01-15 13:46 ` Mike Galbraith
2012-01-15 14:04 ` Mike Galbraith
2012-01-15 14:23 ` Mike Galbraith
2012-01-25 11:27 ` Mike Galbraith
2012-02-15 14:16 ` Thomas Gleixner
2012-02-15 14:37 ` Dimitri Sivanich
2012-02-15 14:52 ` Thomas Gleixner
2012-02-15 15:34 ` Dimitri Sivanich
2012-02-15 20:36 ` Thomas Gleixner
2012-02-16 14:59 ` Dimitri Sivanich
2013-03-19 17:03 ` [PATCH][RFC] " Jiri Bohac
-- strict thread matches above, loose matches on Subject: below --
2011-08-17 16:07 [PATCH] " Dimitri Sivanich
2011-08-17 16:47 ` Thomas Gleixner
2011-08-23 19:56 ` Dimitri Sivanich
2011-09-02 8:19 ` Thomas Gleixner
2011-09-02 19:29 ` Dimitri Sivanich
2011-09-02 19:57 ` Thomas Gleixner
2011-09-02 20:39 ` Dimitri Sivanich
2011-08-03 19:57 Dimitri Sivanich
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