* Mel Gorman <mgorman@xxxxxxx> wrote: > On Thu, Dec 19, 2013 at 05:49:25PM +0100, Ingo Molnar wrote: > > > > * Mel Gorman <mgorman@xxxxxxx> wrote: > > > > > [...] > > > > > > Because we lack data on TLB range flush distributions I think we > > > should still go with the conservative choice for the TLB flush > > > shift. The worst case is really bad here and it's painfully obvious > > > on ebizzy. > > > > So I'm obviously much in favor of this - I'd in fact suggest > > making the conservative choice on _all_ CPU models that have > > aggressive TLB range values right now, because frankly the testing > > used to pick those values does not look all that convincing to me. > > I think the choices there are already reasonably conservative. I'd > be reluctant to support merging a patch that made a choice on all > CPU models without having access to the machines to run tests on. I > don't see the Intel people volunteering to do the necessary testing. So based on this thread I lost confidence in test results on all CPU models but the one you tested. I see two workable options right now: - We turn the feature off on all other CPU models, until someone measures and tunes them reliably. or - We make all tunings that are more aggressive than yours to match yours. In the future people can measure and argue for more aggressive tunings. Thanks, Ingo -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>