[Xen-devel] Re: [PATCH 03 of 36] x86: add memory barriers to wrmsr

[Arjan van de Ven <arjan@xxxxxxxxxxxxx>]

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...


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