On Wed, 2015-05-06 at 11:41 -0400, Rik van Riel wrote: > On Wed, 06 May 2015 13:35:30 +0300 > Artem Bityutskiy <dedeki...@gmail.com> wrote: > > > we observe a tremendous regression between kernel version 3.16 and 3.17 > > (and up), and I've bisected it to this commit: > > > > a43455a sched/numa: Ensure task_numa_migrate() checks the preferred node > > Artem, Jirka, does this patch fix (or at least improve) the issues you > have been seeing? Does it introduce any new regressions?
Hi Rik, first of all thanks for your help! I've tried this patch and it has very small effect. I've also ran the benchmark with auto-NUMA disabled too, which is useful, I think. I used the tip of Linuses tree (v4.1-rc2+). Kernel Avg response time, ms ------------------------------------------------------ Vanilla 1481 Patched 1240 Reverted 256 Disabled 309 Vanilla: pristine v4.1-rc2+ Patched: Vanilla + this patch Reverted: Vanilla + a revert of a43455a Disabled: Vanilla and auto-NUMA disabled via procfs I ran the benchmark for 1 hour for every configuration this time. I cannot say for sure the deviation right now, but I think it is tens of milliseconds, so disabled vs reverted _may_ be within the error range, but I need to do more experiments. So this patch dropped the average Web server response time dropped from about 1.4 seconds to about 1.2 seconds, which isn't a bad improvement, but it is far less than what we get when reverting that patch. Artem. -- 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/
