From: Will Deacon <will.deacon@arm.com>
To: Nicolas Pitre <nico@fluxnic.net>
Cc: "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
Peter Zijlstra <a.p.zijlstra@chello.nl>,
Ingo Molnar <mingo@elte.hu>, Thomas Gleixner <tglx@linutronix.de>,
Chris Mason <chris.mason@fusionio.com>,
Arnd Bergmann <arnd@arndb.de>,
"linux-arm-kernel@lists.infradead.org"
<linux-arm-kernel@lists.infradead.org>
Subject: Re: RFC: mutex: hung tasks on SMP platforms with asm-generic/mutex-xchg.h
Date: Tue, 7 Aug 2012 18:38:10 +0100 [thread overview]
Message-ID: <20120807173810.GE16877@mudshark.cambridge.arm.com> (raw)
In-Reply-To: <20120807173344.GD16877@mudshark.cambridge.arm.com>
On Tue, Aug 07, 2012 at 06:33:44PM +0100, Will Deacon wrote:
> What I think is happening is that B writes the -1 in __mutex_lock_common
> and, after seeing a NULL owner (C may not have set that yet), drops through
> to the:
>
> if (atomic_xchg(&lock->count, -1) == 1)
> goto done;
Sorry, should have proofread that. I meant to say:
What I think is happening is that B writes the -1 in __mutex_lock_common
after seeing a NULL owner (C may not have set that yet) and dropping through
to the:
if (atomic_xchg(&lock->count, -1) == 1)
goto done;
Will
next prev parent reply other threads:[~2012-08-07 17:38 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-08-07 11:56 Will Deacon
2012-08-07 13:48 ` Peter Zijlstra
2012-08-07 14:04 ` Will Deacon
2012-08-07 17:14 ` Nicolas Pitre
2012-08-07 17:33 ` Will Deacon
2012-08-07 17:38 ` Will Deacon [this message]
2012-08-07 18:28 ` Nicolas Pitre
2012-08-09 5:12 ` Nicolas Pitre
2012-08-09 14:49 ` Will Deacon
2012-08-09 16:17 ` Nicolas Pitre
2012-08-09 16:57 ` Nicolas Pitre
2012-08-09 17:50 ` Will Deacon
2012-08-09 18:09 ` Nicolas Pitre
2012-08-09 18:17 ` Will Deacon
2012-08-09 20:05 ` Nicolas Pitre
2012-08-13 8:15 ` Peter Zijlstra
2012-08-13 9:13 ` Will Deacon
2012-08-13 13:35 ` Nicolas Pitre
2012-08-13 14:05 ` Peter Zijlstra
2012-08-13 14:11 ` Will Deacon
2012-08-13 14:45 ` Peter Zijlstra
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