We have a field named 'nr_free' for every memory-region in the region allocator. Keep it updated with the count of freepages in that region. We already run a loop while moving freepages in bulk between the buddy allocator and the region allocator. Reuse that to update the freepages count as well. Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@xxxxxxxxxxxxxxxxxx> --- mm/page_alloc.c | 45 ++++++++++++++++++++++++++++++++++----------- 1 file changed, 34 insertions(+), 11 deletions(-) diff --git a/mm/page_alloc.c b/mm/page_alloc.c index d71d671..ee6c098 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -697,10 +697,12 @@ out: * Add all the freepages contained in 'list' to the buddy freelist * 'free_list'. Using suitable list-manipulation tricks, we move the * pages between the lists in one shot. + * + * Returns the number of pages moved. */ -static void add_to_freelist_bulk(struct list_head *list, - struct free_list *free_list, int order, - int region_id) +static unsigned long +add_to_freelist_bulk(struct list_head *list, struct free_list *free_list, + int order, int region_id) { struct list_head *cur, *position; struct mem_region_list *region; @@ -709,7 +711,7 @@ static void add_to_freelist_bulk(struct list_head *list, struct page *page; if (list_empty(list)) - return; + return 0; page = list_first_entry(list, struct page, lru); list_del(&page->lru); @@ -737,6 +739,8 @@ static void add_to_freelist_bulk(struct list_head *list, /* Fix up the zone region stats, since add_to_freelist() altered it */ region->zone_region->nr_free -= 1 << order; + + return nr_pages + 1; } /** @@ -858,10 +862,12 @@ page_found: * Delete all freepages belonging to the region 'region_id' from 'free_list' * and move them to 'list'. Using suitable list-manipulation tricks, we move * the pages between the lists in one shot. + * + * Returns the number of pages moved. */ -static void del_from_freelist_bulk(struct list_head *list, - struct free_list *free_list, int order, - int region_id) +static unsigned long +del_from_freelist_bulk(struct list_head *list, struct free_list *free_list, + int order, int region_id) { struct mem_region_list *region, *prev_region; unsigned long nr_pages = 0; @@ -907,6 +913,8 @@ static void del_from_freelist_bulk(struct list_head *list, /* Fix up the zone region stats, since del_from_freelist() altered it */ region->zone_region->nr_free += 1 << order; + + return nr_pages + 1; } /** @@ -924,7 +932,9 @@ static void add_to_region_allocator(struct zone *z, struct free_list *free_list, int region_id) { struct region_allocator *reg_alloc; + struct free_area_region *reg_area; struct list_head *ralloc_list; + unsigned long nr_pages; int order; if (WARN_ON(list_empty(&free_list->list))) @@ -934,9 +944,14 @@ static void add_to_region_allocator(struct zone *z, struct free_list *free_list, struct page, lru)); reg_alloc = &z->region_allocator; - ralloc_list = ®_alloc->region[region_id].region_area[order].list; + reg_area = ®_alloc->region[region_id].region_area[order]; + ralloc_list = ®_area->list; + + nr_pages = del_from_freelist_bulk(ralloc_list, free_list, order, + region_id); - del_from_freelist_bulk(ralloc_list, free_list, order, region_id); + WARN_ON(reg_area->nr_free != 0); + reg_area->nr_free += nr_pages; } /* Delete freepages from the region allocator and add them to buddy freelists */ @@ -944,8 +959,10 @@ static int del_from_region_allocator(struct zone *zone, unsigned int order, int migratetype) { struct region_allocator *reg_alloc; + struct free_area_region *reg_area; struct list_head *ralloc_list; struct free_list *free_list; + unsigned long nr_pages; int next_region; reg_alloc = &zone->region_allocator; @@ -954,10 +971,16 @@ static int del_from_region_allocator(struct zone *zone, unsigned int order, if (next_region < 0) return -ENOMEM; - ralloc_list = ®_alloc->region[next_region].region_area[order].list; + reg_area = ®_alloc->region[next_region].region_area[order]; + ralloc_list = ®_area->list; + free_list = &zone->free_area[order].free_list[migratetype]; - add_to_freelist_bulk(ralloc_list, free_list, order, next_region); + nr_pages = add_to_freelist_bulk(ralloc_list, free_list, order, + next_region); + + reg_area->nr_free -= nr_pages; + WARN_ON(reg_area->nr_free != 0); return 0; } -- 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>