The patch titled page allocator: update NR_FREE_PAGES only as necessary has been added to the -mm tree. Its filename is page-allocator-update-nr_free_pages-only-as-necessary.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: update NR_FREE_PAGES only as necessary From: Mel Gorman <mel@xxxxxxxxx> When pages are being freed to the buddy allocator, the zone NR_FREE_PAGES counter must be updated. In the case of bulk per-cpu page freeing, it's updated once per page. This retouches cache lines more than necessary. Update the counters one per per-cpu bulk free. Signed-off-by: Mel Gorman <mel@xxxxxxxxx> Reviewed-by: Christoph Lameter <cl@xxxxxxxxxxxxxxxxxxxx> Reviewed-by: 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 | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) diff -puN mm/page_alloc.c~page-allocator-update-nr_free_pages-only-as-necessary mm/page_alloc.c --- a/mm/page_alloc.c~page-allocator-update-nr_free_pages-only-as-necessary +++ a/mm/page_alloc.c @@ -460,7 +460,6 @@ static inline void __free_one_page(struc int migratetype) { unsigned long page_idx; - int order_size = 1 << order; if (unlikely(PageCompound(page))) if (unlikely(destroy_compound_page(page, order))) @@ -470,10 +469,9 @@ static inline void __free_one_page(struc page_idx = page_to_pfn(page) & ((1 << MAX_ORDER) - 1); - VM_BUG_ON(page_idx & (order_size - 1)); + VM_BUG_ON(page_idx & ((1 << order) - 1)); VM_BUG_ON(bad_range(zone, page)); - __mod_zone_page_state(zone, NR_FREE_PAGES, order_size); while (order < MAX_ORDER-1) { unsigned long combined_idx; struct page *buddy; @@ -528,6 +526,8 @@ static void free_pages_bulk(struct zone spin_lock(&zone->lock); zone_clear_flag(zone, ZONE_ALL_UNRECLAIMABLE); zone->pages_scanned = 0; + + __mod_zone_page_state(zone, NR_FREE_PAGES, count); while (count--) { struct page *page; @@ -546,6 +546,8 @@ static void free_one_page(struct zone *z spin_lock(&zone->lock); zone_clear_flag(zone, ZONE_ALL_UNRECLAIMABLE); zone->pages_scanned = 0; + + __mod_zone_page_state(zone, NR_FREE_PAGES, 1 << order); __free_one_page(page, zone, order, migratetype); spin_unlock(&zone->lock); } @@ -690,7 +692,6 @@ struct page *__rmqueue_smallest(struct z list_del(&page->lru); rmv_page_order(page); area->nr_free--; - __mod_zone_page_state(zone, NR_FREE_PAGES, - (1UL << order)); expand(zone, page, order, current_order, area, migratetype); return page; } @@ -830,8 +831,6 @@ __rmqueue_fallback(struct zone *zone, in /* Remove the page from the freelists */ list_del(&page->lru); rmv_page_order(page); - __mod_zone_page_state(zone, NR_FREE_PAGES, - -(1UL << order)); if (current_order == pageblock_order) set_pageblock_migratetype(page, @@ -904,6 +903,7 @@ static int rmqueue_bulk(struct zone *zon set_page_private(page, migratetype); list = &page->lru; } + __mod_zone_page_state(zone, NR_FREE_PAGES, -(i << order)); spin_unlock(&zone->lock); return i; } _ 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