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Re: [Xen-devel] [PATCH] i386 linux: make 32-bit PAE kernel work when built with newer gcc

On 17 Mar 2006, at 12:28, Jan Beulich wrote:

Indeed, then this should be needed on native, too. I have to admit that
I hadn't read about x86 processors using speculative writes (Intel's SDM, Vol 3, section 7.2.2 clearly doesn't say anything like that, and AMD doesn't
seem to have references to such behavior in their SDM either).

It wouldn't be described there since the effect of this behaviour is only seen on the bus, but not visible to programmers. From the p.o.v of the programmer, stores will always be seen by software to happen in order and no earlier than previous loads. Hence no serialising LOCK prefix needed in spin_unlock(). So actually executing a store speculatively would be both bizarre and illegal anyway on x86.

Will you send the patch to the appropriate person for it to be committed to native?

 -- Keir

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