Messages in this thread | | | Date | Wed, 1 Jul 2009 08:27:32 +0200 | From | Andi Kleen <> | Subject | Re: [PATCH] net: fix race in the receive/select |
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On Wed, Jul 01, 2009 at 11:39:24AM +0800, Herbert Xu wrote: > Andi Kleen <andi@firstfloor.org> wrote: > > > > At least on x86 I can't see how it happens. mb() is only a compile > > time barrier and the compiler doesn't optimize over indirect callbacks > > like __pollwait() anyways. > > mb() does more than just a compiler barrier, it also issues mfence.
mfence is not needed for normal C code (not using non temporal stores) in the Linux memory model on x86 and is a no-op. Only the compile time barrier matters.
-Andi
-- ak@linux.intel.com -- Speaking for myself only.
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