Re: [BUG FIX] Make x86_32 uni-processor Atomic ops, Atomic

From: Andi Kleen
Date: Fri May 22 2009 - 18:08:55 EST


> That's what I meant: AIUI, LOCK_PREFIX has always only been used for
> inter-processor interaction (atomic variables, spinlocks, etc.), not for

PCI has a locked transaction, but I don't think it's widely supported.
With normal uncached access it is also not very useful.

> processor-device interaction.

Well in Linux yes, but not architecturally in x86. That is why the CPUs
don't just nop it out with a single core (which Michael assumes they do,
but they don't)

-Andi

--
ak@xxxxxxxxxxxxxxx -- Speaking for myself only.
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