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xen-devel
[Xen-devel] Re: [PATCH 03 of 36] x86: add memory barriers to wrmsr
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To: |
Jeremy Fitzhardinge <jeremy@xxxxxxxx> |
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Subject: |
[Xen-devel] Re: [PATCH 03 of 36] x86: add memory barriers to wrmsr |
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From: |
Arjan van de Ven <arjan@xxxxxxxxxxxxx> |
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Date: |
Tue, 24 Jun 2008 21:44:41 -0700 |
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Cc: |
Mark McLoughlin <markmc@xxxxxxxxxx>, xen-devel <xen-devel@xxxxxxxxxxxxxxxxxxx>, Eduardo Habkost <ehabkost@xxxxxxxxxx>, Stephen Tweedie <sct@xxxxxxxxxx>, x86@xxxxxxxxxx, LKML <linux-kernel@xxxxxxxxxxxxxxx>, Ingo Molnar <mingo@xxxxxxx> |
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Wed, 25 Jun 2008 10:02:46 -0700 |
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On Wed, 25 Jun 2008 00:18:59 -0400
Jeremy Fitzhardinge <jeremy@xxxxxxxx> wrote:
> wrmsr is a special instruction which can have arbitrary system-wide
> effects. We don't want the compiler to reorder it with respect to
> memory operations, so make it a memory barrier.
it's more readable for several of these cases to stick a barrier(); in
front and after it to be honest; that makes it more explicit that
these are deliberate compiler barriers rather than "actual" memory
access...
--
If you want to reach me at my work email, use arjan@xxxxxxxxxxxxxxx
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