From: "Bryan O'Sullivan" <bos@pathscale.com>
To: Jes Sorensen <jes@sgi.com>
Cc: Andi Kleen <ak@suse.de>, linux-kernel@vger.kernel.org
Subject: Re: Why is wmb() a no-op on x86_64?
Date: Wed, 18 Jan 2006 09:23:27 -0800 [thread overview]
Message-ID: <1137605007.4757.57.camel@serpentine.pathscale.com> (raw)
In-Reply-To: <yq04q41qxcw.fsf@jaguar.mkp.net>
On Wed, 2006-01-18 at 12:06 -0500, Jes Sorensen wrote:
> A job for mmiowb() perhaps?
That might be suitable. It's a no-op on most platforms, but it's only
used by a handful of drivers:
drivers/scsi/qla1280.c
drivers/sn/ioc4.c
drivers/net/bnx2.c
drivers/net/sky2.c
drivers/net/s2io.c
drivers/net/tg3.c
If the semantics were to change so that it really did a write barrier, I
doubt any existing users would notice. In fact, based on the comments
in some drivers, at least some authors think it does already, when it
typically doesn't.
<b
next prev parent reply other threads:[~2006-01-18 17:23 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-01-18 16:23 Why is wmb() a no-op on x86_64? Bryan O'Sullivan
2006-01-18 16:29 ` Andi Kleen
2006-01-18 16:52 ` Bryan O'Sullivan
2006-01-18 17:06 ` Jes Sorensen
2006-01-18 17:23 ` Bryan O'Sullivan [this message]
2006-01-18 17:31 ` [discuss] " Andi Kleen
2006-01-19 10:03 ` Jes Sorensen
2006-01-18 20:07 ` Roland Dreier
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