The patch titled mm: page allocator: drain per-cpu lists after direct reclaim allocation fails has been added to the -mm tree. Its filename is mm-page-allocator-drain-per-cpu-lists-after-direct-reclaim-allocation-fails.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/SubmitChecklist when testing your code *** See http://userweb.kernel.org/~akpm/stuff/added-to-mm.txt to find out what to do about this The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/ ------------------------------------------------------ Subject: mm: page allocator: drain per-cpu lists after direct reclaim allocation fails From: Mel Gorman <mel@xxxxxxxxx> When under significant memory pressure, a process enters direct reclaim and immediately afterwards tries to allocate a page. If it fails and no further progress is made, it's possible the system will go OOM. However, on systems with large amounts of memory, it's possible that a significant number of pages are on per-cpu lists and inaccessible to the calling process. This leads to a process entering direct reclaim more often than it should increasing the pressure on the system and compounding the problem. This patch notes that if direct reclaim is making progress but allocations are still failing that the system is already under heavy pressure. In this case, it drains the per-cpu lists and tries the allocation a second time before continuing. Signed-off-by: Mel Gorman <mel@xxxxxxxxx> Reviewed-by: Minchan Kim <minchan.kim@xxxxxxxxx> Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx> Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx> Reviewed-by: Christoph Lameter <cl@xxxxxxxxx> Cc: Dave Chinner <david@xxxxxxxxxxxxx> Cc: Wu Fengguang <fengguang.wu@xxxxxxxxx> Cc: David Rientjes <rientjes@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/page_alloc.c | 20 ++++++++++++++++---- 1 file changed, 16 insertions(+), 4 deletions(-) diff -puN mm/page_alloc.c~mm-page-allocator-drain-per-cpu-lists-after-direct-reclaim-allocation-fails mm/page_alloc.c --- a/mm/page_alloc.c~mm-page-allocator-drain-per-cpu-lists-after-direct-reclaim-allocation-fails +++ a/mm/page_alloc.c @@ -1847,6 +1847,7 @@ __alloc_pages_direct_reclaim(gfp_t gfp_m struct page *page = NULL; struct reclaim_state reclaim_state; struct task_struct *p = current; + bool drained = false; cond_resched(); @@ -1865,14 +1866,25 @@ __alloc_pages_direct_reclaim(gfp_t gfp_m cond_resched(); - if (order != 0) - drain_all_pages(); + if (unlikely(!(*did_some_progress))) + return NULL; - if (likely(*did_some_progress)) - page = get_page_from_freelist(gfp_mask, nodemask, order, +retry: + page = get_page_from_freelist(gfp_mask, nodemask, order, zonelist, high_zoneidx, alloc_flags, preferred_zone, migratetype); + + /* + * If an allocation failed after direct reclaim, it could be because + * pages are pinned on the per-cpu lists. Drain them and try again + */ + if (!page && !drained) { + drain_all_pages(); + drained = true; + goto retry; + } + return page; } _ Patches currently in -mm which might be from mel@xxxxxxxxx are mm-avoid-warning-when-compaction-is-selected.patch vmstat-update-zone-stat-threshold-when-onlining-a-cpu.patch mm-page-allocator-update-free-page-counters-after-pages-are-placed-on-the-free-list.patch mm-page-allocator-update-free-page-counters-after-pages-are-placed-on-the-free-list-fix.patch mm-page-allocator-calculate-a-better-estimate-of-nr_free_pages-when-memory-is-low-and-kswapd-is-awake.patch mm-page-allocator-drain-per-cpu-lists-after-direct-reclaim-allocation-fails.patch vmscan-do-not-writeback-filesystem-pages-in-direct-reclaim.patch vmscan-kick-flusher-threads-to-clean-pages-when-reclaim-is-encountering-dirty-pages.patch include-linux-pageblock-flagsh-fix-set_pageblock_flags-macro-definiton.patch delay-accounting-re-implement-c-for-getdelaysc-to-report-information-on-a-target-command.patch delay-accounting-re-implement-c-for-getdelaysc-to-report-information-on-a-target-command-checkpatch-fixes.patch add-debugging-aid-for-memory-initialisation-problems.patch -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html