The patch titled page allocator: always wake kswapd when restarting an allocation attempt after direct reclaim failed has been added to the -mm tree. Its filename is page-allocator-always-wake-kswapd-when-restarting-an-allocation-attempt-after-direct-reclaim-failed.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: page allocator: always wake kswapd when restarting an allocation attempt after direct reclaim failed From: Mel Gorman <mel@xxxxxxxxx> If a direct reclaim makes no forward progress, it considers whether it should go OOM or not. Whether OOM is triggered or not, it may retry the allocation afterwards. In times past, this would always wake kswapd as well but currently, kswapd is not woken up after direct reclaim fails. For order-0 allocations, this makes little difference but if there is a heavy mix of higher-order allocations that direct reclaim is failing for, it might mean that kswapd is not rewoken for higher orders as much as it did previously. This patch wakes up kswapd when an allocation is being retried after a direct reclaim failure. It would be expected that kswapd is already awake, but this has the effect of telling kswapd to reclaim at the higher order as well. Signed-off-by: Mel Gorman <mel@xxxxxxxxx> Reviewed-by: Christoph Lameter <cl@xxxxxxxxxxxxxxxxxxxx> Reviewed-by: Pekka Enberg <penberg@xxxxxxxxxxxxxx> Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx> Cc: <stable@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- diff -puN mm/page_alloc.c~page-allocator-always-wake-kswapd-when-restarting-an-allocation-attempt-after-direct-reclaim-failed mm/page_alloc.c --- a/mm/page_alloc.c~page-allocator-always-wake-kswapd-when-restarting-an-allocation-attempt-after-direct-reclaim-failed +++ a/mm/page_alloc.c @@ -1817,9 +1817,9 @@ __alloc_pages_slowpath(gfp_t gfp_mask, u if (NUMA_BUILD && (gfp_mask & GFP_THISNODE) == GFP_THISNODE) goto nopage; +restart: wake_all_kswapd(order, zonelist, high_zoneidx); -restart: /* * OK, we're below the kswapd watermark and have kicked background * reclaim. Now things get more complex, so set up alloc_flags according _ Patches currently in -mm which might be from mel@xxxxxxxxx are mm-order-evictable-rescue-in-lru-putback.patch page-allocator-always-wake-kswapd-when-restarting-an-allocation-attempt-after-direct-reclaim-failed.patch page-allocator-do-not-allow-interrupts-to-use-alloc_harder.patch vmscan-force-kswapd-to-take-notice-faster-when-high-order-watermarks-are-being-hit.patch linux-next.patch mm-warn-once-when-a-page-is-freed-with-pg_mlocked-set.patch mm-add-notifier-in-pageblock-isolation-for-balloon-drivers.patch powerpc-make-the-cmm-memory-hotplug-aware.patch nodemask-make-nodemask_alloc-more-general.patch hugetlb-rework-hstate_next_node_-functions.patch hugetlb-add-nodemask-arg-to-huge-page-alloc-free-and-surplus-adjust-functions.patch hugetlb-add-nodemask-arg-to-huge-page-alloc-free-and-surplus-adjust-functions-fix.patch hugetlb-factor-init_nodemask_of_node.patch hugetlb-derive-huge-pages-nodes-allowed-from-task-mempolicy.patch hugetlb-add-generic-definition-of-numa_no_node.patch hugetlb-add-per-node-hstate-attributes.patch hugetlb-update-hugetlb-documentation-for-numa-controls.patch hugetlb-use-only-nodes-with-memory-for-huge-pages.patch mm-clear-node-in-n_high_memory-and-stop-kswapd-when-all-memory-is-offlined.patch hugetlb-handle-memory-hot-plug-events.patch hugetlb-offload-per-node-attribute-registrations.patch mm-add-gfp-flags-for-nodemask_alloc-slab-allocations.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