From: Ingo Molnar <mingo@elte.hu>
To: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>,
Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: akpm@linux-foundation.org, linux-kernel@vger.kernel.org,
mark.langsdorf@amd.com, arekm@maven.pl,
"H. Peter Anvin" <hpa@zytor.com>,
Andi Kleen <andi@firstfloor.org>, Avi Kivity <avi@qumranet.com>
Subject: Re: [patch 2/2] x86 amd fix cmpxchg read acquire barrier
Date: Thu, 23 Apr 2009 10:06:45 +0200 [thread overview]
Message-ID: <20090423080645.GF22606@elte.hu> (raw)
In-Reply-To: <20090422202453.829846363@polymtl.ca>
* Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> wrote:
> " // Opteron Rev E has a bug in which on very rare occasions a locked
> // instruction doesn't act as a read-acquire barrier if followed by a
> // non-locked read-modify-write instruction. Rev F has this bug in
> // pre-release versions, but not in versions released to customers,
> // so we test only for Rev E, which is family 15, model 32..63 inclusive.
Dunno. The fix looks a bit intrusive (emits a NOP even on good
CPUs). Also, the text above says "not in versions released to
customers".
So unless there's an official erratum or reports in the field (not
from early prototype systems shipped to developers) i'd not rush to
apply it, just yet.
Ingo
next prev parent reply other threads:[~2009-04-23 8:09 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-04-22 20:18 [patch 0/2] Fixing AMD cmpxchg "missing lfence" mess Mathieu Desnoyers
2009-04-22 20:18 ` [patch 1/2] x86: cleanup alternative.h Mathieu Desnoyers
2009-04-28 13:05 ` [GIT PULL] " Mathieu Desnoyers
2009-04-28 14:58 ` Ingo Molnar
2009-04-28 15:13 ` [GIT PULL] x86: cleanup alternative.h (v2) Mathieu Desnoyers
2009-04-29 6:17 ` [tip:x86/asm] x86: clean up alternative.h tip-bot for Mathieu Desnoyers
2009-04-29 6:22 ` Mathieu Desnoyers
2009-04-28 17:40 ` [GIT PULL] x86: cleanup alternative.h H. Peter Anvin
2009-04-28 18:11 ` Mathieu Desnoyers
2009-04-28 18:13 ` [GIT PULL] x86: cleanup alternative.h (v3) Mathieu Desnoyers
2009-04-22 20:18 ` [patch 2/2] x86 amd fix cmpxchg read acquire barrier Mathieu Desnoyers
2009-04-22 20:59 ` Alan Cox
2009-04-22 22:47 ` Mathieu Desnoyers
2009-04-22 22:53 ` Alan Cox
2009-04-22 23:26 ` Mathieu Desnoyers
2009-04-23 8:06 ` Ingo Molnar [this message]
2009-04-23 13:19 ` Mathieu Desnoyers
2009-04-23 13:41 ` Arkadiusz Miskiewicz
2009-04-23 22:17 ` Mathieu Desnoyers
2009-04-25 8:19 ` Pavel Machek
2009-05-02 15:55 ` Mathieu Desnoyers
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