diff options
| -rw-r--r-- | mm/page_alloc.c | 62 |
1 files changed, 37 insertions, 25 deletions
diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 2c25de46c58f..2f1118b4dda4 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -1948,23 +1948,44 @@ static bool can_steal_fallback(unsigned int order, int start_mt) * use it's pages as requested migratetype in the future. */ static void steal_suitable_fallback(struct zone *zone, struct page *page, - int start_type) + int start_type, bool whole_block) { unsigned int current_order = page_order(page); + struct free_area *area; int pages; + /* + * This can happen due to races and we want to prevent broken + * highatomic accounting. + */ + if (is_migrate_highatomic_page(page)) + goto single_page; + /* Take ownership for orders >= pageblock_order */ if (current_order >= pageblock_order) { change_pageblock_range(page, current_order, start_type); - return; + goto single_page; } + /* We are not allowed to try stealing from the whole block */ + if (!whole_block) + goto single_page; + pages = move_freepages_block(zone, page, start_type); + /* moving whole block can fail due to zone boundary conditions */ + if (!pages) + goto single_page; /* Claim the whole block if over half of it is free */ if (pages >= (1 << (pageblock_order-1)) || page_group_by_mobility_disabled) set_pageblock_migratetype(page, start_type); + + return; + +single_page: + area = &zone->free_area[current_order]; + list_move(&page->lru, &area->free_list[start_type]); } /* @@ -2123,8 +2144,13 @@ static bool unreserve_highatomic_pageblock(const struct alloc_context *ac, return false; } -/* Remove an element from the buddy allocator from the fallback list */ -static inline struct page * +/* + * Try finding a free buddy page on the fallback list and put it on the free + * list of requested migratetype, possibly along with other pages from the same + * block, depending on fragmentation avoidance heuristics. Returns true if + * fallback was found so that __rmqueue_smallest() can grab it. + */ +static inline bool __rmqueue_fallback(struct zone *zone, unsigned int order, int start_migratetype) { struct free_area *area; @@ -2145,32 +2171,17 @@ __rmqueue_fallback(struct zone *zone, unsigned int order, int start_migratetype) page = list_first_entry(&area->free_list[fallback_mt], struct page, lru); - if (can_steal && !is_migrate_highatomic_page(page)) - steal_suitable_fallback(zone, page, start_migratetype); - /* Remove the page from the freelists */ - area->nr_free--; - list_del(&page->lru); - rmv_page_order(page); - - expand(zone, page, order, current_order, area, - start_migratetype); - /* - * The pcppage_migratetype may differ from pageblock's - * migratetype depending on the decisions in - * find_suitable_fallback(). This is OK as long as it does not - * differ for MIGRATE_CMA pageblocks. Those can be used as - * fallback only via special __rmqueue_cma_fallback() function - */ - set_pcppage_migratetype(page, start_migratetype); + steal_suitable_fallback(zone, page, start_migratetype, + can_steal); trace_mm_page_alloc_extfrag(page, order, current_order, start_migratetype, fallback_mt); - return page; + return true; } - return NULL; + return false; } /* @@ -2182,13 +2193,14 @@ static struct page *__rmqueue(struct zone *zone, unsigned int order, { struct page *page; +retry: page = __rmqueue_smallest(zone, order, migratetype); if (unlikely(!page)) { if (migratetype == MIGRATE_MOVABLE) page = __rmqueue_cma_fallback(zone, order); - if (!page) - page = __rmqueue_fallback(zone, order, migratetype); + if (!page && __rmqueue_fallback(zone, order, migratetype)) + goto retry; } trace_mm_page_alloc_zone_locked(page, order, migratetype); |