This helper function only factors out the code flow within each order during fallback. There is no function change.
Signed-off-by: ChengYi He <[email protected]> --- mm/page_alloc.c | 79 +++++++++++++++++++++++++++++++++------------------------ 1 file changed, 46 insertions(+), 33 deletions(-) diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 63358d9..50c325a 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -1752,51 +1752,64 @@ static void unreserve_highatomic_pageblock(const struct alloc_context *ac) } } -/* Remove an element from the buddy allocator from the fallback list */ static inline struct page * -__rmqueue_fallback(struct zone *zone, unsigned int order, int start_migratetype) +__rmqueue_fallback_order(struct zone *zone, unsigned int order, + int start_migratetype, int current_order) { struct free_area *area; - unsigned int current_order; struct page *page; int fallback_mt; bool can_steal; - /* Find the largest possible block of pages in the other list */ - for (current_order = MAX_ORDER-1; - current_order >= order && current_order <= MAX_ORDER-1; - --current_order) { - area = &(zone->free_area[current_order]); - fallback_mt = find_suitable_fallback(area, current_order, - start_migratetype, false, &can_steal); - if (fallback_mt == -1) - continue; + area = &(zone->free_area[current_order]); + fallback_mt = find_suitable_fallback(area, current_order, + start_migratetype, false, &can_steal); + if (fallback_mt == -1) + return NULL; - page = list_first_entry(&area->free_list[fallback_mt], - struct page, lru); - if (can_steal) - steal_suitable_fallback(zone, page, start_migratetype); + page = list_first_entry(&area->free_list[fallback_mt], + struct page, lru); + if (can_steal) + steal_suitable_fallback(zone, page, start_migratetype); - /* Remove the page from the freelists */ - area->nr_free--; - list_del(&page->lru); - rmv_page_order(page); + /* 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); + 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); - trace_mm_page_alloc_extfrag(page, order, current_order, - start_migratetype, fallback_mt); + trace_mm_page_alloc_extfrag(page, order, current_order, + start_migratetype, fallback_mt); - return page; + return page; +} + +/* Remove an element from the buddy allocator from the fallback list */ +static inline struct page * +__rmqueue_fallback(struct zone *zone, unsigned int order, int start_migratetype) +{ + unsigned int current_order; + struct page *page; + + /* Find the largest possible block of pages in the other list */ + for (current_order = MAX_ORDER-1; + current_order >= order && current_order <= MAX_ORDER-1; + --current_order) { + page = __rmqueue_fallback_order(zone, order, start_migratetype, + current_order); + + if (page) + return page; } return NULL; -- 1.9.1
