Re: [PATCH 00/18] x86: Ticket lock + cmpxchg cleanup

[Linus Torvalds]

On Wed, Aug 24, 2011 at 4:05 PM, H. Peter Anvin <hpa@xxxxxxxxx> wrote:
>
> That's not guaranteed in any way to generate a locally atomic instruction.

No such guarantee is needed - we hold the lock (until the last store),
so as long as it doesn't do anything completely crazy, then the
"head++" will work.

However, the reason I disagree with it is that I don't think that it's
any prettier at all to have the two barriers than it is to just have
the asm.

I see no advantage of a three-line "pseudo-C" code with two magic
barriers over just doing it with the inline asm. The fact that the
inline asm also makes the OOSTORE case trivial is just gravy.

                     Linus
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