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author | Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> | 2013-01-04 15:35:08 -0800 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2013-01-04 16:11:46 -0800 |
commit | a458431e176ddb27e8ef8b98c2a681b217337393 (patch) | |
tree | 466ec91a25ebbe30870d12486071bb08a8c7cd5a | |
parent | 358e419f826b552c9d795bcd3820597217692461 (diff) | |
download | linux-stable-a458431e176ddb27e8ef8b98c2a681b217337393.tar.gz linux-stable-a458431e176ddb27e8ef8b98c2a681b217337393.tar.bz2 linux-stable-a458431e176ddb27e8ef8b98c2a681b217337393.zip |
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 <t.stanislaws@samsung.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Aaditya Kumar <aaditya.kumar.30@gmail.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Michal Nazarewicz <mina86@mina86.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r-- | include/linux/mmzone.h | 8 | ||||
-rw-r--r-- | mm/page_alloc.c | 27 | ||||
-rw-r--r-- | mm/page_isolation.c | 26 |
3 files changed, 2 insertions, 59 deletions
diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h index 4bec5be82cab..73b64a38b984 100644 --- a/include/linux/mmzone.h +++ b/include/linux/mmzone.h @@ -503,14 +503,6 @@ struct zone { * rarely used fields: */ const char *name; -#ifdef CONFIG_MEMORY_ISOLATION - /* - * the number of MIGRATE_ISOLATE *pageblock*. - * We need this for free page counting. Look at zone_watermark_ok_safe. - * It's protected by zone->lock - */ - int nr_pageblock_isolate; -#endif } ____cacheline_internodealigned_in_smp; typedef enum { diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 4ba5e37127fc..bc6cc0e913bd 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -221,11 +221,6 @@ EXPORT_SYMBOL(nr_online_nodes); int page_group_by_mobility_disabled __read_mostly; -/* - * NOTE: - * Don't use set_pageblock_migratetype(page, MIGRATE_ISOLATE) directly. - * Instead, use {un}set_pageblock_isolate. - */ void set_pageblock_migratetype(struct page *page, int migratetype) { @@ -1655,20 +1650,6 @@ static bool __zone_watermark_ok(struct zone *z, int order, unsigned long mark, return true; } -#ifdef CONFIG_MEMORY_ISOLATION -static inline unsigned long nr_zone_isolate_freepages(struct zone *zone) -{ - if (unlikely(zone->nr_pageblock_isolate)) - return zone->nr_pageblock_isolate * pageblock_nr_pages; - return 0; -} -#else -static inline unsigned long nr_zone_isolate_freepages(struct zone *zone) -{ - return 0; -} -#endif - bool zone_watermark_ok(struct zone *z, int order, unsigned long mark, int classzone_idx, int alloc_flags) { @@ -1684,14 +1665,6 @@ bool zone_watermark_ok_safe(struct zone *z, int order, unsigned long mark, if (z->percpu_drift_mark && free_pages < z->percpu_drift_mark) free_pages = zone_page_state_snapshot(z, NR_FREE_PAGES); - /* - * If the zone has MIGRATE_ISOLATE type free pages, we should consider - * it. nr_zone_isolate_freepages is never accurate so kswapd might not - * sleep although it could do so. But this is more desirable for memory - * hotplug than sleeping which can cause a livelock in the direct - * reclaim path. - */ - free_pages -= nr_zone_isolate_freepages(z); return __zone_watermark_ok(z, order, mark, classzone_idx, alloc_flags, free_pages); } 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 <linux/memory.h> #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); } |