From: Peter Zijlstra <peterz@infradead.org>
To: "H. Peter Anvin" <hpa@zytor.com>
Cc: Pranith Kumar <bobby.prani@gmail.com>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>,
"maintainer:X86 ARCHITECTURE (32-BIT AND 64-BIT)"
<x86@kernel.org>,
"open list:X86 ARCHITECTURE (32-BIT AND 64-BIT)"
<linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] x86: cmpxchg_double: Add missing memory clobber
Date: Wed, 7 Oct 2015 15:00:36 +0200 [thread overview]
Message-ID: <20151007130036.GB7520@twins.programming.kicks-ass.net> (raw)
In-Reply-To: <56143F76.2010902@zytor.com>
On Tue, Oct 06, 2015 at 02:39:02PM -0700, H. Peter Anvin wrote:
> However, I think one of the major uses for cmpxchg_double() is for page
> table manipulation, and for that it isn't clear that a compiler barrier
> is needed nor desired.
See mm/slub.c, that uses cmpxchg_double() (the LOCK prefixed one) and
one would expect that to also include a compiler barrier.
prev parent reply other threads:[~2015-10-07 13:00 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-10-06 18:54 Pranith Kumar
2015-10-06 20:16 ` H. Peter Anvin
2015-10-06 20:29 ` Pranith Kumar
2015-10-06 21:39 ` H. Peter Anvin
2015-10-07 13:00 ` Peter Zijlstra [this message]
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