On Tue, 2013-11-26 at 12:56 +0100, Peter Zijlstra wrote: > On Tue, Nov 26, 2013 at 12:21:40PM +0100, Ingo Molnar wrote: > > I'm somewhat reluctant to chalk it up to a single mfence - maybe > > timings/behavior changed in some substantial way?
That would be nthread mfence calls. > > Ah indeed! We also changed the case where an enqueueing futex sees the > uval change and bails. It is now far more expensive due to having to > both queue and unqueue, whereas before it wouldn't queue at all. Right, but those particular numbers do not measure that path. Thanks, Davidlohr -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
