Messages in this thread | | | Date | Wed, 24 Aug 2011 16:05:23 -0700 | From | "H. Peter Anvin" <> | Subject | Re: [PATCH 00/18] x86: Ticket lock + cmpxchg cleanup |
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On 08/24/2011 03:59 PM, Jeremy Fitzhardinge wrote: > On 08/24/2011 03:53 PM, Linus Torvalds wrote: >> On Wed, Aug 24, 2011 at 1:10 PM, Jeremy Fitzhardinge <jeremy@goop.org> wrote: >>> Could we just kill SMP support for OOSTORE machines now? That would be >>> the cleanest possible fix... >> No it wouldn't. The asm version would *still* be cleaner than the "C >> plus random barriers". >> >> It's not like the C version is "portable" in any case. > > If there's no need to have a locked instruction, then it could simply be: > > barrier(); > lock->head++; > barrier(); > > with no need for asm at all. >
That's not guaranteed in any way to generate a locally atomic instruction.
-hpa
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