On Sat, 2013-11-23 at 13:01 +0100, Peter Zijlstra wrote: > > I used to have a patch to schedule() that would always immediately fall > > through and only actually block on the second call; it illustrated the > > problem really well, in fact so well the kernels fails to boot most > > times. > > I found the below on my filesystem -- making it apply shouldn't be hard. > Making it work is the same effort as that patch you sent, we need to > guarantee all schedule() callers can deal with not actually sleeping -- > aka. spurious wakeups.
Thanks, I'll definitely try the patch and see what comes up. > > I don't think anybody ever got that thing to run reliable enough to see > if the idea proposed in the patch made any difference to actual > workloads though. Since your idea can also be applied to sysv sems (patch 3/3 back then), I can definitely do some Oracle runs which IIRC, also likes doing multiple wakeups at once. In any case this patch deals very nicely with our customer workload, which is why I believe its particularly good here. Thanks, Davidlohr -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
