The patch titled mm: stop kswapd's infinite loop at high order allocation has been removed from the -mm tree. Its filename was mm-stop-kswapds-infinite-loop-at-high-order-allocation-take2.patch This patch was dropped because it was merged into mainline or a subsystem tree The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/ ------------------------------------------------------ Subject: mm: stop kswapd's infinite loop at high order allocation From: KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx> Wassim Dagash reported following kswapd infinite loop problem. kswapd runs in some infinite loop trying to swap until order 10 of zone highmem is OK.... kswapd will continue to try to balance order 10 of zone highmem forever (or until someone release a very large chunk of highmem). For non order-0 allocations, the system may never be balanced due to fragmentation but kswapd should not infinitely loop as a result. Instead, recheck all watermarks at order-0 as they are the most important. If watermarks are ok, kswapd will go back to sleep. [akpm@xxxxxxxxxxxxxxxxxxxx: fix comment] Reported-by: wassim dagash <wassim.dagash@xxxxxxxxx> Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx> Reviewed-by: Nick Piggin <npiggin@xxxxxxx> Signed-off-by: Mel Gorman <mel@xxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/vmscan.c | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) diff -puN mm/vmscan.c~mm-stop-kswapds-infinite-loop-at-high-order-allocation-take2 mm/vmscan.c --- a/mm/vmscan.c~mm-stop-kswapds-infinite-loop-at-high-order-allocation-take2 +++ a/mm/vmscan.c @@ -1867,6 +1867,23 @@ out: try_to_freeze(); + /* + * Fragmentation may mean that the system cannot be + * rebalanced for high-order allocations in all zones. + * At this point, if nr_reclaimed < SWAP_CLUSTER_MAX, + * it means the zones have been fully scanned and are still + * not balanced. For high-order allocations, there is + * little point trying all over again as kswapd may + * infinite loop. + * + * Instead, recheck all watermarks at order-0 as they + * are the most important. If watermarks are ok, kswapd will go + * back to sleep. High-order users can still perform direct + * reclaim if they wish. + */ + if (sc.nr_reclaimed < SWAP_CLUSTER_MAX) + order = sc.order = 0; + goto loop_again; } _ Patches currently in -mm which might be from kosaki.motohiro@xxxxxxxxxxxxxx are origin.patch getrusage-fill-ru_maxrss-value.patch softirq-introduce-statistics-for-softirq.patch proc-export-statistics-for-softirq-to-proc.patch proc-update-document-for-proc-softirqs-and-proc-stat.patch devices-cgroup-allow-mkfifo.patch memcg-new-force_empty-to-free-pages-under-group-fix.patch memcg-new-force_empty-to-free-pages-under-group-fix-fix.patch memcg-revert-gfp-mask-fix.patch memcg-check-group-leader-fix.patch memcg-memoryswap-controller-fix-limit-check.patch memcg-swapout-refcnt-fix.patch memcg-hierarchy-avoid-unnecessary-reclaim.patch inactive_anon_is_low-move-to-vmscan.patch mm-introduce-zone_reclaim-struct.patch mm-add-zone-nr_pages-helper-function.patch mm-make-get_scan_ratio-safe-for-memcg.patch memcg-add-null-check-to-page_cgroup_zoneinfo.patch memcg-add-inactive_anon_is_low.patch memcg-add-inactive_anon_is_low-vmscan-style-cleanup.patch memcg-add-mem_cgroup_zone_nr_pages.patch memcg-add-zone_reclaim_stat.patch memcg-add-zone_reclaim_stat-reclaim-stat-trivial-fixes.patch memcg-add-zone_reclaim_stat-reclaim-stat-trivial-fixes-fix.patch memcg-remove-mem_cgroup_cal_reclaim.patch memcg-show-reclaim-stat.patch memcg-rename-scan-global-lru.patch memcg-protect-prev_priority.patch memcg-swappiness.patch memcg-fix-calclation-of-active_ratio.patch memcg-fix-calclation-of-active_ratio-build-error-fix.patch memcg-show-real-limit-under-hierarchy-mode.patch memcg-explain-details-and-test-document.patch ia64-implement-interrupt-enabling-rwlocks-fix.patch fs-symlink-write_begin-allocation-context-fix-reiser4-fix.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