From: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx> We don't need to split freepages with holding the zone lock. It will cause more contention on zone lock so not desirable. v3: fix un-isolated case Link: http://lkml.kernel.org/r/1464230275-25791-1-git-send-email-iamjoonsoo.kim@xxxxxxx Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx> Acked-by: Vlastimil Babka <vbabka@xxxxxxx> Cc: Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx> Cc: Minchan Kim <minchan@xxxxxxxxxx> Cc: Alexander Potapenko <glider@xxxxxxxxxx> Cc: Hugh Dickins <hughd@xxxxxxxxxx> Cc: Michal Hocko <mhocko@xxxxxxxxxx> --- include/linux/mm.h | 1 - mm/compaction.c | 47 +++++++++++++++++++++++++++++++++-------------- mm/page_alloc.c | 27 --------------------------- 3 files changed, 33 insertions(+), 42 deletions(-) diff --git a/include/linux/mm.h b/include/linux/mm.h index 558949e..15b3bc9 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -562,7 +562,6 @@ void __put_page(struct page *page); void put_pages_list(struct list_head *pages); void split_page(struct page *page, unsigned int order); -int split_free_page(struct page *page); /* * Compound pages have a destructor function. Provide a diff --git a/mm/compaction.c b/mm/compaction.c index d1d2063..5557421 100644 --- a/mm/compaction.c +++ b/mm/compaction.c @@ -64,13 +64,31 @@ static unsigned long release_freepages(struct list_head *freelist) static void map_pages(struct list_head *list) { - struct page *page; + unsigned int i, order, nr_pages; + struct page *page, *next; + LIST_HEAD(tmp_list); + + list_for_each_entry_safe(page, next, list, lru) { + list_del(&page->lru); - list_for_each_entry(page, list, lru) { - arch_alloc_page(page, 0); - kernel_map_pages(page, 1, 1); - kasan_alloc_pages(page, 0); + order = page_private(page); + nr_pages = 1 << order; + set_page_private(page, 0); + set_page_refcounted(page); + + arch_alloc_page(page, order); + kernel_map_pages(page, nr_pages, 1); + kasan_alloc_pages(page, order); + if (order) + split_page(page, order); + + for (i = 0; i < nr_pages; i++) { + list_add(&page->lru, &tmp_list); + page++; + } } + + list_splice(&tmp_list, list); } static inline bool migrate_async_suitable(int migratetype) @@ -405,12 +423,13 @@ static unsigned long isolate_freepages_block(struct compact_control *cc, unsigned long flags = 0; bool locked = false; unsigned long blockpfn = *start_pfn; + unsigned int order; cursor = pfn_to_page(blockpfn); /* Isolate free pages. */ for (; blockpfn < end_pfn; blockpfn++, cursor++) { - int isolated, i; + int isolated; struct page *page = cursor; /* @@ -476,16 +495,16 @@ static unsigned long isolate_freepages_block(struct compact_control *cc, goto isolate_fail; } - /* Found a free page, break it into order-0 pages */ - isolated = split_free_page(page); - total_isolated += isolated; - for (i = 0; i < isolated; i++) { - list_add(&page->lru, freelist); - page++; - } + /* Found a free page, will break it into order-0 pages */ + order = page_order(page); + isolated = __isolate_free_page(page, order); - /* If a page was split, advance to the end of it */ + /* If a page was isolated, advance to the end of it */ if (isolated) { + set_page_private(page, order); + total_isolated += isolated; + list_add_tail(&page->lru, freelist); + cc->nr_freepages += isolated; if (!strict && cc->nr_migratepages <= cc->nr_freepages) { diff --git a/mm/page_alloc.c b/mm/page_alloc.c index e08186a..e07f424 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -2532,33 +2532,6 @@ int __isolate_free_page(struct page *page, unsigned int order) } /* - * Similar to split_page except the page is already free. As this is only - * being used for migration, the migratetype of the block also changes. - * As this is called with interrupts disabled, the caller is responsible - * for calling arch_alloc_page() and kernel_map_page() after interrupts - * are enabled. - * - * Note: this is probably too low level an operation for use in drivers. - * Please consult with lkml before using this in your driver. - */ -int split_free_page(struct page *page) -{ - unsigned int order; - int nr_pages; - - order = page_order(page); - - nr_pages = __isolate_free_page(page, order); - if (!nr_pages) - return 0; - - /* Split into individual pages */ - set_page_refcounted(page); - split_page(page, order); - return nr_pages; -} - -/* * Update NUMA hit/miss statistics * * Must be called with interrupts disabled. -- 1.9.1 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>