Messages in this thread | | | Date | Wed, 01 Apr 2009 20:47:41 +0200 | From | Eric Dumazet <> | Subject | Re: [PATCH] x86: percpu_to_op() misses memory and flags clobbers |
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Jeremy Fitzhardinge a écrit : > Eric Dumazet wrote: >> +#define percpu_inc(var) percpu_to_op0("inc", per_cpu__##var) >> +#define percpu_dec(var) percpu_to_op0("dec", per_cpu__##var) >> > > There's probably not a lot of value in this. The Intel and AMD > optimisation guides tend to deprecate inc/dec in favour of using > add/sub, because the former can cause pipeline stalls due to its partial > flags update. > > J
Sure, but this saves one byte per call, this is probably why we still use inc/dec in so many places...
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