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

From: Andi Kleen
Date: Fri May 22 2009 - 16:36:48 EST


> If it: "Does not make a difference" then it "Should not make a difference"
> but it does, try it yourself. Its safe (if LOCK_PREFIX is in the proper
> places) - the machine will ignore the opcode if is recent enough to not
> need it - just trust the cpu's micro-code.

It doesn't ignore it, in fact it's extremly slow on some older systems
where all atomic operations are very costly.
That is why LOCK is avoided as much as possible.

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