Messages in this thread | | | Date | Thu, 29 Nov 2012 13:20:00 -0800 | From | "H. Peter Anvin" <> | Subject | Re: [PATCH 8/8] x86, cleanups: Simplify sync_core() in the case of no CPUID |
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On 11/29/2012 01:18 PM, Borislav Petkov wrote: > On Thu, Nov 29, 2012 at 01:06:20PM -0800, H. Peter Anvin wrote: >> It doesn't matter in that context, as the surrounding MSR references >> have barriers, but what I'm refering to is the "memory" barrier. > > Ok, but the only difference between the two versions is this line: > > movl %esi, %ecx # tmp144, ecx > > coming from the cpuid_eax() function. So the memory barrier is the same > and in the right place in both cases. >
In the case of that one call site, yes, because the MSR references include the barrier. Other sites, current or future, may not have the same property.
-hpa
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