Messages in this thread | | | Date | Thu, 17 Dec 2009 14:43:33 -0600 (CST) | From | Christoph Lameter <> | Subject | Re: [this_cpu_xx V7 0/8] Per cpu atomics in core allocators and cleanup |
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On Thu, 17 Dec 2009, Mathieu Desnoyers wrote:
> Some quick test on my Intel Xeon E5405: > > local cmpxchg: 14 cycles > xchg: 18 cycles > > So yes, indeed, the non-LOCK prefixed local cmpxchg seems a bit faster > than the xchg, given the latter has an implied LOCK prefix. > > Code used for local cmpxchg: > old = var; > do { > ret = cmpxchg_local(&var, old, 4); > if (likely(ret == old)) > break; > old = ret; > } while (1); >
Great. Could you also put that into "patch-format"?
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