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Re: [Xen-devel] [PATCH] i386 linux: make 32-bit PAE kernel work when bui

To: "Jan Beulich" <JBeulich@xxxxxxxxxx>
Subject: Re: [Xen-devel] [PATCH] i386 linux: make 32-bit PAE kernel work when built with newer gcc
From: Keir Fraser <Keir.Fraser@xxxxxxxxxxxx>
Date: Tue, 14 Mar 2006 10:09:29 +0000
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On 13 Mar 2006, at 16:40, Jan Beulich wrote:

The compiler isn't required to order the two stores ptep_get_and_clear_full() in any particular way, and we saw cases where the upper 32 bits get stored before the lower ones, which causes the access to fail (page-fault propagated out of
Xen).

Won't this need a barrier() (compile barrier) between the updates of low and high portions?

 -- Keir


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