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From: will.deacon@arm.com (Will Deacon)
To: linux-arm-kernel@lists.infradead.org
Subject: [RFC PATCH] ARM64: cmpxchg.h: Clear the exclusive access bit on fail
Date: Fri, 27 Feb 2015 10:06:13 +0000	[thread overview]
Message-ID: <20150227100612.GB3628@arm.com> (raw)
In-Reply-To: <1425016026-19766-1-git-send-email-bobby.prani@gmail.com>

On Fri, Feb 27, 2015 at 05:46:55AM +0000, Pranith Kumar wrote:
> In cmpxchg(), we do a load exclusive on an address and upon a comparison fail,
> we skip the store exclusive instruction. This can result in the exclusive bit
> still set. If there was a store exclusive after this to the same address, that
> will see the exclusive bit set. This should not happen.

... and the problem with that is?

> We need to clear the exclusive bit in these cases.

Why?

Will

  reply	other threads:[~2015-02-27 10:06 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-02-27  5:46 [RFC PATCH] ARM64: cmpxchg.h: Clear the exclusive access bit on fail Pranith Kumar
2015-02-27 10:06 ` Will Deacon [this message]
2015-02-27 18:25   ` Pranith Kumar
2015-02-27 18:33     ` Catalin Marinas
2015-02-27 18:44       ` Pranith Kumar
2015-02-27 19:08         ` Mark Rutland
2015-02-27 19:15           ` Pranith Kumar
2015-02-27 19:33             ` Mark Rutland

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