diff options
| -rw-r--r-- | include/linux/page-isolation.h | 5 | ||||
| -rw-r--r-- | mm/page_alloc.c | 74 | ||||
| -rw-r--r-- | mm/page_isolation.c | 5 |
3 files changed, 63 insertions, 21 deletions
diff --git a/include/linux/page-isolation.h b/include/linux/page-isolation.h index 047d64706f2a..d4cd2014fa6f 100644 --- a/include/linux/page-isolation.h +++ b/include/linux/page-isolation.h @@ -33,10 +33,7 @@ bool has_unmovable_pages(struct zone *zone, struct page *page, int count, bool skip_hwpoisoned_pages); void set_pageblock_migratetype(struct page *page, int migratetype); int move_freepages_block(struct zone *zone, struct page *page, - int migratetype); -int move_freepages(struct zone *zone, - struct page *start_page, struct page *end_page, - int migratetype); + int migratetype, int *num_movable); /* * Changes migrate type in [start_pfn, end_pfn) to be MIGRATE_ISOLATE. diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 2f1118b4dda4..d90792addeb9 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -1832,9 +1832,9 @@ static inline struct page *__rmqueue_cma_fallback(struct zone *zone, * Note that start_page and end_pages are not aligned on a pageblock * boundary. If alignment is required, use move_freepages_block() */ -int move_freepages(struct zone *zone, +static int move_freepages(struct zone *zone, struct page *start_page, struct page *end_page, - int migratetype) + int migratetype, int *num_movable) { struct page *page; unsigned int order; @@ -1851,6 +1851,9 @@ int move_freepages(struct zone *zone, VM_BUG_ON(page_zone(start_page) != page_zone(end_page)); #endif + if (num_movable) + *num_movable = 0; + for (page = start_page; page <= end_page;) { if (!pfn_valid_within(page_to_pfn(page))) { page++; @@ -1861,6 +1864,15 @@ int move_freepages(struct zone *zone, VM_BUG_ON_PAGE(page_to_nid(page) != zone_to_nid(zone), page); if (!PageBuddy(page)) { + /* + * We assume that pages that could be isolated for + * migration are movable. But we don't actually try + * isolating, as that would be expensive. + */ + if (num_movable && + (PageLRU(page) || __PageMovable(page))) + (*num_movable)++; + page++; continue; } @@ -1876,7 +1888,7 @@ int move_freepages(struct zone *zone, } int move_freepages_block(struct zone *zone, struct page *page, - int migratetype) + int migratetype, int *num_movable) { unsigned long start_pfn, end_pfn; struct page *start_page, *end_page; @@ -1893,7 +1905,8 @@ int move_freepages_block(struct zone *zone, struct page *page, if (!zone_spans_pfn(zone, end_pfn)) return 0; - return move_freepages(zone, start_page, end_page, migratetype); + return move_freepages(zone, start_page, end_page, migratetype, + num_movable); } static void change_pageblock_range(struct page *pageblock_page, @@ -1943,22 +1956,26 @@ static bool can_steal_fallback(unsigned int order, int start_mt) /* * This function implements actual steal behaviour. If order is large enough, * we can steal whole pageblock. If not, we first move freepages in this - * pageblock and check whether half of pages are moved or not. If half of - * pages are moved, we can change migratetype of pageblock and permanently - * use it's pages as requested migratetype in the future. + * pageblock to our migratetype and determine how many already-allocated pages + * are there in the pageblock with a compatible migratetype. If at least half + * of pages are free or compatible, we can change migratetype of the pageblock + * itself, so pages freed in the future will be put on the correct free list. */ static void steal_suitable_fallback(struct zone *zone, struct page *page, int start_type, bool whole_block) { unsigned int current_order = page_order(page); struct free_area *area; - int pages; + int free_pages, movable_pages, alike_pages; + int old_block_type; + + old_block_type = get_pageblock_migratetype(page); /* * This can happen due to races and we want to prevent broken * highatomic accounting. */ - if (is_migrate_highatomic_page(page)) + if (is_migrate_highatomic(old_block_type)) goto single_page; /* Take ownership for orders >= pageblock_order */ @@ -1971,13 +1988,39 @@ static void steal_suitable_fallback(struct zone *zone, struct page *page, if (!whole_block) goto single_page; - pages = move_freepages_block(zone, page, start_type); + free_pages = move_freepages_block(zone, page, start_type, + &movable_pages); + /* + * Determine how many pages are compatible with our allocation. + * For movable allocation, it's the number of movable pages which + * we just obtained. For other types it's a bit more tricky. + */ + if (start_type == MIGRATE_MOVABLE) { + alike_pages = movable_pages; + } else { + /* + * If we are falling back a RECLAIMABLE or UNMOVABLE allocation + * to MOVABLE pageblock, consider all non-movable pages as + * compatible. If it's UNMOVABLE falling back to RECLAIMABLE or + * vice versa, be conservative since we can't distinguish the + * exact migratetype of non-movable pages. + */ + if (old_block_type == MIGRATE_MOVABLE) + alike_pages = pageblock_nr_pages + - (free_pages + movable_pages); + else + alike_pages = 0; + } + /* moving whole block can fail due to zone boundary conditions */ - if (!pages) + if (!free_pages) goto single_page; - /* Claim the whole block if over half of it is free */ - if (pages >= (1 << (pageblock_order-1)) || + /* + * If a sufficient number of pages in the block are either free or of + * comparable migratability as our allocation, claim the whole block. + */ + if (free_pages + alike_pages >= (1 << (pageblock_order-1)) || page_group_by_mobility_disabled) set_pageblock_migratetype(page, start_type); @@ -2055,7 +2098,7 @@ static void reserve_highatomic_pageblock(struct page *page, struct zone *zone, && !is_migrate_cma(mt)) { zone->nr_reserved_highatomic += pageblock_nr_pages; set_pageblock_migratetype(page, MIGRATE_HIGHATOMIC); - move_freepages_block(zone, page, MIGRATE_HIGHATOMIC); + move_freepages_block(zone, page, MIGRATE_HIGHATOMIC, NULL); } out_unlock: @@ -2132,7 +2175,8 @@ static bool unreserve_highatomic_pageblock(const struct alloc_context *ac, * may increase. */ set_pageblock_migratetype(page, ac->migratetype); - ret = move_freepages_block(zone, page, ac->migratetype); + ret = move_freepages_block(zone, page, ac->migratetype, + NULL); if (ret) { spin_unlock_irqrestore(&zone->lock, flags); return ret; diff --git a/mm/page_isolation.c b/mm/page_isolation.c index 7927bbb54a4e..5092e4ef00c8 100644 --- a/mm/page_isolation.c +++ b/mm/page_isolation.c @@ -66,7 +66,8 @@ out: set_pageblock_migratetype(page, MIGRATE_ISOLATE); zone->nr_isolate_pageblock++; - nr_pages = move_freepages_block(zone, page, MIGRATE_ISOLATE); + nr_pages = move_freepages_block(zone, page, MIGRATE_ISOLATE, + NULL); __mod_zone_freepage_state(zone, -nr_pages, migratetype); } @@ -120,7 +121,7 @@ static void unset_migratetype_isolate(struct page *page, unsigned migratetype) * pageblock scanning for freepage moving. */ if (!isolated_page) { - nr_pages = move_freepages_block(zone, page, migratetype); + nr_pages = move_freepages_block(zone, page, migratetype, NULL); __mod_zone_freepage_state(zone, nr_pages, migratetype); } set_pageblock_migratetype(page, migratetype); |