On Tue, Nov 13, 2012 at 03:41:02PM -0800, David Rientjes wrote: > On Tue, 13 Nov 2012, Andy Lutomirski wrote: > > > It just happened again. > > > > $ grep -E "compact_|thp_" /proc/vmstat > > compact_blocks_moved 8332448774 > > compact_pages_moved 21831286 > > compact_pagemigrate_failed 211260 > > compact_stall 13484 > > compact_fail 6717 > > compact_success 6755 > > thp_fault_alloc 150665 > > thp_fault_fallback 4270 > > thp_collapse_alloc 19771 > > thp_collapse_alloc_failed 2188 > > thp_split 19600 > > > > Two of the patches from the list provided at > http://marc.info/?l=linux-mm&m=135179005510688 are already in your 3.6.3 > kernel: > > mm: compaction: abort compaction loop if lock is contended or run too > long > mm: compaction: acquire the zone->lock as late as possible > > and all have not made it to the 3.6 stable kernel yet, so would it be > possible to try with 3.7-rc5 to see if it fixes the issue? If so, it will > indicate that the entire series is a candidate to backport to 3.6.
Thanks David once again. The full list of compaction-related patches I believe are necessary for this particular problem are e64c5237cf6ff474cb2f3f832f48f2b441dd9979 mm: compaction: abort compaction loop if lock is contended or run too long 3cc668f4e30fbd97b3c0574d8cac7a83903c9bc7 mm: compaction: move fatal signal check out of compact_checklock_irqsave 661c4cb9b829110cb68c18ea05a56be39f75a4d2 mm: compaction: Update try_to_compact_pages()kerneldoc comment 2a1402aa044b55c2d30ab0ed9405693ef06fb07c mm: compaction: acquire the zone->lru_lock as late as possible f40d1e42bb988d2a26e8e111ea4c4c7bac819b7e mm: compaction: acquire the zone->lock as late as possible 753341a4b85ff337487b9959c71c529f522004f4 revert "mm: have order > 0 compaction start off where it left" bb13ffeb9f6bfeb301443994dfbf29f91117dfb3 mm: compaction: cache if a pageblock was scanned and no pages were isolated c89511ab2f8fe2b47585e60da8af7fd213ec877e mm: compaction: Restart compaction from near where it left off 62997027ca5b3d4618198ed8b1aba40b61b1137b mm: compaction: clear PG_migrate_skip based on compaction and reclaim activity 0db63d7e25f96e2c6da925c002badf6f144ddf30 mm: compaction: correct the nr_strict va isolated check for CMA If we can get confirmation that these fix the problem in 3.6 kernels then I can backport them to -stable. This fixing a problem where "many processes stall, all in an isolation-related function". This started happening after lumpy reclaim was removed because we depended on that to aggressively reclaim with less compaction. Now compaction is depended upon more. The full 3.7-rc5 kernel has a different problem on top of this and it's important the problems do not get conflacted. It has these fixes *but* GFP_NO_KSWAPD has been removed and there is a patch that scales reclaim with THP failures that is causing problem. With them, kswapd can get stuck in a 100% loop where it is neither reclaiming nor reaching its exit conditions. The correct fix would be to identify why this happens but I have not got around to it yet. To test with 3.7-rc5 then apply either 1) https://lkml.org/lkml/2012/11/5/308 2) https://lkml.org/lkml/2012/11/12/113 or 1) https://lkml.org/lkml/2012/11/5/308 3) https://lkml.org/lkml/2012/11/12/151 on top of 3.7-rc5. So it's a lot of work but there are three tests I'm interested in hearing about. The results of each determine what happens in -stable or mainline Test 1: 3.6 + the last of commits above (should fix processes stick in isolate) Test 2: 3.7-rc5 + (1+2) above (should fix kswapd stuck at 100%) Test 3: 3.7-rc5 + (1+3) above (should fix kswapd stuck at 100% but better) Thanks. -- Mel Gorman SUSE Labs -- 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/
