Hi all If someone can provide the patches (or learn me how to get them with git (I apologise to not be git savy)) then, this weekend, I can apply them to 3.6.6 and compare before/after to check if they fix #49361. Thanks On 2012 Nov 14, Mel Gorman wrote: > 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 > -- -- Marc Duponcheel Velodroomstraat 74 - 2600 Berchem - Belgium +32 (0)478 68.10.91 - marc@xxxxxxxxxx -- 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>