From a458431e176ddb27e8ef8b98c2a681b217337393 Mon Sep 17 00:00:00 2001 From: Bartlomiej Zolnierkiewicz Date: Fri, 4 Jan 2013 15:35:08 -0800 Subject: mm: fix zone_watermark_ok_safe() accounting of isolated pages Commit 702d1a6e0766 ("memory-hotplug: fix kswapd looping forever problem") added an isolated pageblocks counter (nr_pageblock_isolate in struct zone) and used it to adjust free pages counter in zone_watermark_ok_safe() to prevent kswapd looping forever problem. Then later, commit 2139cbe627b8 ("cma: fix counting of isolated pages") fixed accounting of isolated pages in global free pages counter. It made the previous zone_watermark_ok_safe() fix unnecessary and potentially harmful (cause now isolated pages may be accounted twice making free pages counter incorrect). This patch removes the special isolated pageblocks counter altogether which fixes zone_watermark_ok_safe() free pages check. Reported-by: Tomasz Stanislawski Signed-off-by: Bartlomiej Zolnierkiewicz Signed-off-by: Kyungmin Park Cc: Minchan Kim Cc: KOSAKI Motohiro Cc: Aaditya Kumar Cc: KAMEZAWA Hiroyuki Cc: Mel Gorman Cc: Michal Hocko Cc: Marek Szyprowski Cc: Michal Nazarewicz Cc: Hugh Dickins Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/page_isolation.c | 26 ++------------------------ 1 file changed, 2 insertions(+), 24 deletions(-) (limited to 'mm/page_isolation.c') diff --git a/mm/page_isolation.c b/mm/page_isolation.c index 9d2264ea4606..383bdbb98b04 100644 --- a/mm/page_isolation.c +++ b/mm/page_isolation.c @@ -8,28 +8,6 @@ #include #include "internal.h" -/* called while holding zone->lock */ -static void set_pageblock_isolate(struct page *page) -{ - if (get_pageblock_migratetype(page) == MIGRATE_ISOLATE) - return; - - set_pageblock_migratetype(page, MIGRATE_ISOLATE); - page_zone(page)->nr_pageblock_isolate++; -} - -/* called while holding zone->lock */ -static void restore_pageblock_isolate(struct page *page, int migratetype) -{ - struct zone *zone = page_zone(page); - if (WARN_ON(get_pageblock_migratetype(page) != MIGRATE_ISOLATE)) - return; - - BUG_ON(zone->nr_pageblock_isolate <= 0); - set_pageblock_migratetype(page, migratetype); - zone->nr_pageblock_isolate--; -} - int set_migratetype_isolate(struct page *page, bool skip_hwpoisoned_pages) { struct zone *zone; @@ -80,7 +58,7 @@ out: unsigned long nr_pages; int migratetype = get_pageblock_migratetype(page); - set_pageblock_isolate(page); + set_pageblock_migratetype(page, MIGRATE_ISOLATE); nr_pages = move_freepages_block(zone, page, MIGRATE_ISOLATE); __mod_zone_freepage_state(zone, -nr_pages, migratetype); @@ -103,7 +81,7 @@ void unset_migratetype_isolate(struct page *page, unsigned migratetype) goto out; nr_pages = move_freepages_block(zone, page, migratetype); __mod_zone_freepage_state(zone, nr_pages, migratetype); - restore_pageblock_isolate(page, migratetype); + set_pageblock_migratetype(page, migratetype); out: spin_unlock_irqrestore(&zone->lock, flags); } -- cgit v1.2.3-59-g8ed1b