From: Ingo Molnar <mingo@elte.hu>
To: Jason Wessel <jason.wessel@windriver.com>
Cc: lkml <linux-kernel@vger.kernel.org>,
Andrew Morton <akpm@linux-foundation.org>,
a.p.zijlstra@chello.nl
Subject: Re: [PATCH] softlockup: fix NMI hangs due to lock race - 2.6.26-rc regression
Date: Mon, 2 Jun 2008 12:39:31 +0200 [thread overview]
Message-ID: <20080602103931.GA898@elte.hu> (raw)
In-Reply-To: <483C4391.8040002@windriver.com>
* Jason Wessel <jason.wessel@windriver.com> wrote:
> The touch_nmi_watchdog() routine on x86 ultimately calls
> touch_softlockup_watchdog(). The problem is that to touch the
> softlockup watchdog, the cpu_clock code has to be called which could
> involve multiple cpu locks and can lead to a hard hang if one of the
> locks is held by a processor that is not going to return anytime soon
> (such as could be the case with kgdb or perhaps even with some other
> kind of exception).
>
> This patch causes the public version of the
> touch_softlockup_watchdog() to defer the cpu clock access to a later
> point.
applied to tip/core/softlockup and cherry-picked it into tip/core/urgent
as well for v2.6.26 merge. Thanks,
Ingo
prev parent reply other threads:[~2008-06-02 10:39 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-05-27 17:23 [PATCH] softlockup: fix NMI hangs due to lock race - 2.6.26-rc regression Jason Wessel
2008-05-27 17:28 ` Peter Zijlstra
2008-05-28 13:31 ` Jason Wessel
2008-06-02 10:39 ` Ingo Molnar [this message]
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