diff options
| -rw-r--r-- | include/linux/page-isolation.h | 3 | ||||
| -rw-r--r-- | mm/page_alloc.c | 174 | ||||
| -rw-r--r-- | mm/page_isolation.c | 22 |
3 files changed, 121 insertions, 78 deletions
diff --git a/include/linux/page-isolation.h b/include/linux/page-isolation.h index 4ac34392823a..8550b3c91480 100644 --- a/include/linux/page-isolation.h +++ b/include/linux/page-isolation.h @@ -34,8 +34,7 @@ static inline bool is_migrate_isolate(int migratetype) #define REPORT_FAILURE 0x2 void set_pageblock_migratetype(struct page *page, int migratetype); -int move_freepages_block(struct zone *zone, struct page *page, - int migratetype, int *num_movable); +int move_freepages_block(struct zone *zone, struct page *page, int migratetype); int start_isolate_page_range(unsigned long start_pfn, unsigned long end_pfn, int migratetype, int flags, gfp_t gfp_flags); diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 0e223d5b94fa..a7cfe65e45c1 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -1601,9 +1601,8 @@ 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() */ -static int move_freepages(struct zone *zone, - unsigned long start_pfn, unsigned long end_pfn, - int migratetype, int *num_movable) +static int move_freepages(struct zone *zone, unsigned long start_pfn, + unsigned long end_pfn, int migratetype) { struct page *page; unsigned long pfn; @@ -1613,14 +1612,6 @@ static int move_freepages(struct zone *zone, for (pfn = start_pfn; pfn <= end_pfn;) { page = pfn_to_page(pfn); 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)++; pfn++; continue; } @@ -1638,17 +1629,16 @@ static int move_freepages(struct zone *zone, return pages_moved; } -int move_freepages_block(struct zone *zone, struct page *page, - int migratetype, int *num_movable) +static bool prep_move_freepages_block(struct zone *zone, struct page *page, + unsigned long *start_pfn, + unsigned long *end_pfn, + int *num_free, int *num_movable) { - unsigned long start_pfn, end_pfn, pfn; - - if (num_movable) - *num_movable = 0; + unsigned long pfn, start, end; pfn = page_to_pfn(page); - start_pfn = pageblock_start_pfn(pfn); - end_pfn = pageblock_end_pfn(pfn) - 1; + start = pageblock_start_pfn(pfn); + end = pageblock_end_pfn(pfn) - 1; /* * The caller only has the lock for @zone, don't touch ranges @@ -1657,13 +1647,50 @@ int move_freepages_block(struct zone *zone, struct page *page, * accompanied by other operations such as migratetype updates * which also should be locked. */ - if (!zone_spans_pfn(zone, start_pfn)) - return 0; - if (!zone_spans_pfn(zone, end_pfn)) - return 0; + if (!zone_spans_pfn(zone, start)) + return false; + if (!zone_spans_pfn(zone, end)) + return false; + + *start_pfn = start; + *end_pfn = end; - return move_freepages(zone, start_pfn, end_pfn, migratetype, - num_movable); + if (num_free) { + *num_free = 0; + *num_movable = 0; + for (pfn = start; pfn <= end;) { + page = pfn_to_page(pfn); + if (PageBuddy(page)) { + int nr = 1 << buddy_order(page); + + *num_free += nr; + pfn += nr; + continue; + } + /* + * 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 (PageLRU(page) || __PageMovable(page)) + (*num_movable)++; + pfn++; + } + } + + return true; +} + +int move_freepages_block(struct zone *zone, struct page *page, + int migratetype) +{ + unsigned long start_pfn, end_pfn; + + if (!prep_move_freepages_block(zone, page, &start_pfn, &end_pfn, + NULL, NULL)) + return -1; + + return move_freepages(zone, start_pfn, end_pfn, migratetype); } static void change_pageblock_range(struct page *pageblock_page, @@ -1748,33 +1775,37 @@ static inline bool boost_watermark(struct zone *zone) } /* - * 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 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. + * This function implements actual steal behaviour. If order is large enough, we + * can claim the whole pageblock for the requested migratetype. If not, we check + * the pageblock for constituent pages; if at least half of the pages are free + * or compatible, we can still claim the whole block, so pages freed in the + * future will be put on the correct free list. Otherwise, we isolate exactly + * the order we need from the fallback block and leave its migratetype alone. */ -static void steal_suitable_fallback(struct zone *zone, struct page *page, - unsigned int alloc_flags, int start_type, bool whole_block) +static struct page * +steal_suitable_fallback(struct zone *zone, struct page *page, + int current_order, int order, int start_type, + unsigned int alloc_flags, bool whole_block) { - unsigned int current_order = buddy_order(page); int free_pages, movable_pages, alike_pages; - int old_block_type; + unsigned long start_pfn, end_pfn; + int block_type; - old_block_type = get_pageblock_migratetype(page); + block_type = get_pageblock_migratetype(page); /* * This can happen due to races and we want to prevent broken * highatomic accounting. */ - if (is_migrate_highatomic(old_block_type)) + if (is_migrate_highatomic(block_type)) goto single_page; /* Take ownership for orders >= pageblock_order */ if (current_order >= pageblock_order) { + del_page_from_free_list(page, zone, current_order); change_pageblock_range(page, current_order, start_type); - goto single_page; + expand(zone, page, order, current_order, start_type); + return page; } /* @@ -1789,10 +1820,9 @@ static void steal_suitable_fallback(struct zone *zone, struct page *page, if (!whole_block) goto single_page; - free_pages = move_freepages_block(zone, page, start_type, - &movable_pages); /* moving whole block can fail due to zone boundary conditions */ - if (!free_pages) + if (!prep_move_freepages_block(zone, page, &start_pfn, &end_pfn, + &free_pages, &movable_pages)) goto single_page; /* @@ -1810,7 +1840,7 @@ static void steal_suitable_fallback(struct zone *zone, struct page *page, * vice versa, be conservative since we can't distinguish the * exact migratetype of non-movable pages. */ - if (old_block_type == MIGRATE_MOVABLE) + if (block_type == MIGRATE_MOVABLE) alike_pages = pageblock_nr_pages - (free_pages + movable_pages); else @@ -1821,13 +1851,16 @@ static void steal_suitable_fallback(struct zone *zone, struct page *page, * compatible migratability as our allocation, claim the whole block. */ if (free_pages + alike_pages >= (1 << (pageblock_order-1)) || - page_group_by_mobility_disabled) + page_group_by_mobility_disabled) { + move_freepages(zone, start_pfn, end_pfn, start_type); set_pageblock_migratetype(page, start_type); - - return; + return __rmqueue_smallest(zone, order, start_type); + } single_page: - move_to_free_list(page, zone, current_order, start_type); + del_page_from_free_list(page, zone, current_order); + expand(zone, page, order, current_order, block_type); + return page; } /* @@ -1895,9 +1928,10 @@ static void reserve_highatomic_pageblock(struct page *page, struct zone *zone) mt = get_pageblock_migratetype(page); /* Only reserve normal pageblocks (i.e., they can merge with others) */ if (migratetype_is_mergeable(mt)) { - zone->nr_reserved_highatomic += pageblock_nr_pages; - set_pageblock_migratetype(page, MIGRATE_HIGHATOMIC); - move_freepages_block(zone, page, MIGRATE_HIGHATOMIC, NULL); + if (move_freepages_block(zone, page, MIGRATE_HIGHATOMIC) != -1) { + set_pageblock_migratetype(page, MIGRATE_HIGHATOMIC); + zone->nr_reserved_highatomic += pageblock_nr_pages; + } } out_unlock: @@ -1922,7 +1956,7 @@ static bool unreserve_highatomic_pageblock(const struct alloc_context *ac, struct zone *zone; struct page *page; int order; - bool ret; + int ret; for_each_zone_zonelist_nodemask(zone, z, zonelist, ac->highest_zoneidx, ac->nodemask) { @@ -1971,10 +2005,14 @@ static bool unreserve_highatomic_pageblock(const struct alloc_context *ac, * of pageblocks that cannot be completely freed * may increase. */ + ret = move_freepages_block(zone, page, ac->migratetype); + /* + * Reserving this block already succeeded, so this should + * not fail on zone boundaries. + */ + WARN_ON_ONCE(ret == -1); set_pageblock_migratetype(page, ac->migratetype); - ret = move_freepages_block(zone, page, ac->migratetype, - NULL); - if (ret) { + if (ret > 0) { spin_unlock_irqrestore(&zone->lock, flags); return ret; } @@ -1995,7 +2033,7 @@ static bool unreserve_highatomic_pageblock(const struct alloc_context *ac, * deviation from the rest of this file, to make the for loop * condition simpler. */ -static __always_inline bool +static __always_inline struct page * __rmqueue_fallback(struct zone *zone, int order, int start_migratetype, unsigned int alloc_flags) { @@ -2042,7 +2080,7 @@ __rmqueue_fallback(struct zone *zone, int order, int start_migratetype, goto do_steal; } - return false; + return NULL; find_smallest: for (current_order = order; current_order < NR_PAGE_ORDERS; current_order++) { @@ -2062,14 +2100,14 @@ find_smallest: do_steal: page = get_page_from_free_area(area, fallback_mt); - steal_suitable_fallback(zone, page, alloc_flags, start_migratetype, - can_steal); + /* take off list, maybe claim block, expand remainder */ + page = steal_suitable_fallback(zone, page, current_order, order, + start_migratetype, alloc_flags, can_steal); trace_mm_page_alloc_extfrag(page, order, current_order, start_migratetype, fallback_mt); - return true; - + return page; } /* @@ -2096,15 +2134,15 @@ __rmqueue(struct zone *zone, unsigned int order, int migratetype, return page; } } -retry: + page = __rmqueue_smallest(zone, order, migratetype); if (unlikely(!page)) { if (alloc_flags & ALLOC_CMA) page = __rmqueue_cma_fallback(zone, order); - if (!page && __rmqueue_fallback(zone, order, migratetype, - alloc_flags)) - goto retry; + if (!page) + page = __rmqueue_fallback(zone, order, migratetype, + alloc_flags); } return page; } @@ -2659,12 +2697,10 @@ int __isolate_free_page(struct page *page, unsigned int order) * Only change normal pageblocks (i.e., they can merge * with others) */ - if (migratetype_is_mergeable(mt)) { - set_pageblock_migratetype(page, - MIGRATE_MOVABLE); - move_freepages_block(zone, page, - MIGRATE_MOVABLE, NULL); - } + if (migratetype_is_mergeable(mt) && + move_freepages_block(zone, page, + MIGRATE_MOVABLE) != -1) + set_pageblock_migratetype(page, MIGRATE_MOVABLE); } } diff --git a/mm/page_isolation.c b/mm/page_isolation.c index a5c8fa4c2a75..71539d7b96cf 100644 --- a/mm/page_isolation.c +++ b/mm/page_isolation.c @@ -178,15 +178,18 @@ static int set_migratetype_isolate(struct page *page, int migratetype, int isol_ unmovable = has_unmovable_pages(check_unmovable_start, check_unmovable_end, migratetype, isol_flags); if (!unmovable) { - unsigned long nr_pages; + int nr_pages; int mt = get_pageblock_migratetype(page); + nr_pages = move_freepages_block(zone, page, MIGRATE_ISOLATE); + /* Block spans zone boundaries? */ + if (nr_pages == -1) { + spin_unlock_irqrestore(&zone->lock, flags); + return -EBUSY; + } + __mod_zone_freepage_state(zone, -nr_pages, mt); set_pageblock_migratetype(page, MIGRATE_ISOLATE); zone->nr_isolate_pageblock++; - nr_pages = move_freepages_block(zone, page, MIGRATE_ISOLATE, - NULL); - - __mod_zone_freepage_state(zone, -nr_pages, mt); spin_unlock_irqrestore(&zone->lock, flags); return 0; } @@ -206,7 +209,7 @@ static int set_migratetype_isolate(struct page *page, int migratetype, int isol_ static void unset_migratetype_isolate(struct page *page, int migratetype) { struct zone *zone; - unsigned long flags, nr_pages; + unsigned long flags; bool isolated_page = false; unsigned int order; struct page *buddy; @@ -252,7 +255,12 @@ static void unset_migratetype_isolate(struct page *page, int migratetype) * allocation. */ if (!isolated_page) { - nr_pages = move_freepages_block(zone, page, migratetype, NULL); + int nr_pages = move_freepages_block(zone, page, migratetype); + /* + * Isolating this block already succeeded, so this + * should not fail on zone boundaries. + */ + WARN_ON_ONCE(nr_pages == -1); __mod_zone_freepage_state(zone, nr_pages, migratetype); } set_pageblock_migratetype(page, migratetype); |