Subject: [merged] mm-compaction-avoid-isolating-pinned-pages.patch removed from -mm tree To: rientjes@xxxxxxxxxx,gthelen@xxxxxxxxxx,hughd@xxxxxxxxxx,iamjoonsoo.kim@xxxxxxx,mgorman@xxxxxxx,riel@xxxxxxxxxx,mm-commits@xxxxxxxxxxxxxxx From: akpm@xxxxxxxxxxxxxxxxxxxx Date: Fri, 04 Apr 2014 12:31:37 -0700 The patch titled Subject: mm, compaction: avoid isolating pinned pages has been removed from the -mm tree. Its filename was mm-compaction-avoid-isolating-pinned-pages.patch This patch was dropped because it was merged into mainline or a subsystem tree ------------------------------------------------------ From: David Rientjes <rientjes@xxxxxxxxxx> Subject: mm, compaction: avoid isolating pinned pages Page migration will fail for memory that is pinned in memory with, for example, get_user_pages(). In this case, it is unnecessary to take zone->lru_lock or isolating the page and passing it to page migration which will ultimately fail. This is a racy check, the page can still change from under us, but in that case we'll just fail later when attempting to move the page. This avoids very expensive memory compaction when faulting transparent hugepages after pinning a lot of memory with a Mellanox driver. On a 128GB machine and pinning ~120GB of memory, before this patch we see the enormous disparity in the number of page migration failures because of the pinning (from /proc/vmstat): compact_pages_moved 8450 compact_pagemigrate_failed 15614415 0.05% of pages isolated are successfully migrated and explicitly triggering memory compaction takes 102 seconds. After the patch: compact_pages_moved 9197 compact_pagemigrate_failed 7 99.9% of pages isolated are now successfully migrated in this configuration and memory compaction takes less than one second. Signed-off-by: David Rientjes <rientjes@xxxxxxxxxx> Acked-by: Hugh Dickins <hughd@xxxxxxxxxx> Acked-by: Mel Gorman <mgorman@xxxxxxx> Cc: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx> Cc: Rik van Riel <riel@xxxxxxxxxx> Cc: Greg Thelen <gthelen@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/compaction.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff -puN mm/compaction.c~mm-compaction-avoid-isolating-pinned-pages mm/compaction.c --- a/mm/compaction.c~mm-compaction-avoid-isolating-pinned-pages +++ a/mm/compaction.c @@ -584,6 +584,15 @@ isolate_migratepages_range(struct zone * continue; } + /* + * Migration will fail if an anonymous page is pinned in memory, + * so avoid taking lru_lock and isolating it unnecessarily in an + * admittedly racy check. + */ + if (!page_mapping(page) && + page_count(page) > page_mapcount(page)) + continue; + /* Check if it is ok to still hold the lock */ locked = compact_checklock_irqsave(&zone->lru_lock, &flags, locked, cc); _ Patches currently in -mm which might be from rientjes@xxxxxxxxxx are origin.patch arch-x86-mm-kmemcheck-kmemcheckc-use-kstrtoint-instead-of-sscanf.patch mm-slab-slub-use-page-list-consistently-instead-of-page-lru.patch mmnuma-reorganize-change_pmd_range.patch mmnuma-reorganize-change_pmd_range-fix.patch move-mmu-notifier-call-from-change_protection-to-change_pmd_range.patch mm-exclude-memory-less-nodes-from-zone_reclaim.patch mm-revert-thp-make-madv_hugepage-check-for-mm-def_flags.patch mm-revert-thp-make-madv_hugepage-check-for-mm-def_flags-ignore-madv_hugepage-on-s390-to-prevent-sigsegv-in-qemu.patch mm-thp-add-vm_init_def_mask-and-prctl_thp_disable.patch exec-kill-the-unnecessary-mm-def_flags-setting-in-load_elf_binary.patch fork-collapse-copy_flags-into-copy_process.patch mm-mempolicy-rename-slab_node-for-clarity.patch mm-mempolicy-remove-per-process-flag.patch res_counter-remove-interface-for-locked-charging-and-uncharging.patch mm-compaction-determine-isolation-mode-only-once.patch mm-try_to_unmap_cluster-should-lock_page-before-mlocking.patch mm-utilc-add-kstrimdup.patch fault-injection-set-bounds-on-what-proc-self-make-it-fail-accepts.patch fault-injection-set-bounds-on-what-proc-self-make-it-fail-accepts-fix.patch linux-next.patch memcg-slab-never-try-to-merge-memcg-caches.patch memcg-slab-cleanup-memcg-cache-creation.patch memcg-slab-separate-memcg-vs-root-cache-creation-paths.patch memcg-slab-unregister-cache-from-memcg-before-starting-to-destroy-it.patch memcg-slab-do-not-destroy-children-caches-if-parent-has-aliases.patch slub-adjust-memcg-caches-when-creating-cache-alias.patch slub-rework-sysfs-layout-for-memcg-caches.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