The patch titled page allocator: do not setup zonelist cache when there is only one node has been added to the -mm tree. Its filename is page-allocator-do-not-setup-zonelist-cache-when-there-is-only-one-node.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: do not setup zonelist cache when there is only one node From: Mel Gorman <mel@xxxxxxxxx> There is a zonelist cache which is used to track zones that are not in the allowed cpuset or found to be recently full. This is to reduce cache footprint on large machines. On smaller machines, it just incurs cost for no gain. This patch only uses the zonelist cache when there are NUMA nodes. Signed-off-by: Mel Gorman <mel@xxxxxxxxx> Reviewed-by: Christoph Lameter <cl@xxxxxxxxxxxxxxxxxxxx> Cc: KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx> Cc: Pekka Enberg <penberg@xxxxxxxxxxxxxx> Cc: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx> Cc: Nick Piggin <nickpiggin@xxxxxxxxxxxx> Cc: Dave Hansen <dave@xxxxxxxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/page_alloc.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff -puN mm/page_alloc.c~page-allocator-do-not-setup-zonelist-cache-when-there-is-only-one-node mm/page_alloc.c --- a/mm/page_alloc.c~page-allocator-do-not-setup-zonelist-cache-when-there-is-only-one-node +++ a/mm/page_alloc.c @@ -1467,8 +1467,11 @@ this_zone_full: if (NUMA_BUILD) zlc_mark_zone_full(zonelist, z); try_next_zone: - if (NUMA_BUILD && !did_zlc_setup) { - /* we do zlc_setup after the first zone is tried */ + if (NUMA_BUILD && !did_zlc_setup && num_online_nodes() > 1) { + /* + * we do zlc_setup after the first zone is tried but only + * if there are multiple nodes make it worthwhile + */ allowednodes = zlc_setup(zonelist, alloc_flags); zlc_active = 1; did_zlc_setup = 1; _ Patches currently in -mm which might be from mel@xxxxxxxxx are vmscan-low-order-lumpy-reclaim-also-should-use-pageout_io_sync.patch page-allocator-replace-__alloc_pages_internal-with-__alloc_pages_nodemask.patch page-allocator-do-not-sanity-check-order-in-the-fast-path.patch page-allocator-do-not-sanity-check-order-in-the-fast-path-fix.patch page-allocator-do-not-check-numa-node-id-when-the-caller-knows-the-node-is-valid.patch page-allocator-check-only-once-if-the-zonelist-is-suitable-for-the-allocation.patch page-allocator-break-up-the-allocator-entry-point-into-fast-and-slow-paths.patch page-allocator-move-check-for-disabled-anti-fragmentation-out-of-fastpath.patch page-allocator-calculate-the-preferred-zone-for-allocation-only-once.patch page-allocator-calculate-the-preferred-zone-for-allocation-only-once-fix.patch page-allocator-calculate-the-migratetype-for-allocation-only-once.patch page-allocator-calculate-the-alloc_flags-for-allocation-only-once.patch page-allocator-remove-a-branch-by-assuming-__gfp_high-==-alloc_high.patch page-allocator-inline-__rmqueue_smallest.patch page-allocator-inline-buffered_rmqueue.patch page-allocator-inline-__rmqueue_fallback.patch page-allocator-do-not-call-get_pageblock_migratetype-more-than-necessary.patch page-allocator-do-not-disable-interrupts-in-free_page_mlock.patch page-allocator-do-not-setup-zonelist-cache-when-there-is-only-one-node.patch page-allocator-do-not-check-for-compound-pages-during-the-page-allocator-sanity-checks.patch page-allocator-use-allocation-flags-as-an-index-to-the-zone-watermark.patch page-allocator-update-nr_free_pages-only-as-necessary.patch page-allocator-get-the-pageblock-migratetype-without-disabling-interrupts.patch page-allocator-use-a-pre-calculated-value-instead-of-num_online_nodes-in-fast-paths.patch page-allocator-slab-use-nr_online_nodes-to-check-for-a-numa-platform.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