On Tue, Mar 03, 2015 at 01:43:46PM +0000, Mel Gorman wrote: > On Tue, Mar 03, 2015 at 10:34:37PM +1100, Dave Chinner wrote: > > On Mon, Mar 02, 2015 at 10:56:14PM -0800, Linus Torvalds wrote: > > > On Mon, Mar 2, 2015 at 9:20 PM, Dave Chinner <david@xxxxxxxxxxxxx> wrote: > > > >> > > > >> But are those migrate-page calls really common enough to make these > > > >> things happen often enough on the same pages for this all to matter? > > > > > > > > It's looking like that's a possibility. > > > > > > Hmm. Looking closer, commit 10c1045f28e8 already should have > > > re-introduced the "pte was already NUMA" case. > > > > > > So that's not it either, afaik. Plus your numbers seem to say that > > > it's really "migrate_pages()" that is done more. So it feels like the > > > numa balancing isn't working right. > > > > So that should show up in the vmstats, right? Oh, and there's a > > tracepoint in migrate_pages, too. Same 6x10s samples in phase 3: > > > > The stats indicate both more updates and more faults. Can you try this > please? It's against 4.0-rc1. > > ---8<--- > mm: numa: Reduce amount of IPI traffic due to automatic NUMA balancing Makes no noticable difference to behaviour or performance. Stats: 359,857 migrate:mm_migrate_pages ( +- 5.54% ) numa_hit 36026802 numa_miss 14287 numa_foreign 14287 numa_interleave 18408 numa_local 36006052 numa_other 35037 numa_pte_updates 81803359 numa_huge_pte_updates 0 numa_hint_faults 79810798 numa_hint_faults_local 21227730 numa_pages_migrated 32037516 pgmigrate_success 32037516 pgmigrate_fail 0 -Dave. -- Dave Chinner david@xxxxxxxxxxxxx -- 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>