diff options
| author | Andrew Morton <akpm@linux-foundation.org> | 2015-01-17 11:23:48 +1100 |
|---|---|---|
| committer | Stephen Rothwell <sfr@canb.auug.org.au> | 2015-01-17 11:23:48 +1100 |
| commit | 25a23098055050b3f8e3e22fe4167869ab4d8138 (patch) | |
| tree | 184663072a12244d10acf5a11dad7361b637bd6a /mm/vmscan.c | |
| parent | 3611badc1baa6189e10cb66f58abc016cf51469b (diff) | |
mm-vmscan-fix-the-page-state-calculation-in-too_many_isolated-fix
Move the zone_page_state_snapshot() fallback logic into
too_many_isolated(), so shrink_inactive_list() doesn't incorrectly call
congestion_wait().
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Vinayak Menon <vinmenon@codeaurora.org>
Cc: Vladimir Davydov <vdavydov@parallels.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'mm/vmscan.c')
| -rw-r--r-- | mm/vmscan.c | 23 |
1 files changed, 11 insertions, 12 deletions
diff --git a/mm/vmscan.c b/mm/vmscan.c index 47e42bf1dc5d..175a145bd73a 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -1402,7 +1402,7 @@ int isolate_lru_page(struct page *page) } static int __too_many_isolated(struct zone *zone, int file, - struct scan_control *sc, int safe) + struct scan_control *sc, int safe) { unsigned long inactive, isolated; @@ -1435,7 +1435,7 @@ static int __too_many_isolated(struct zone *zone, int file, * unnecessary swapping, thrashing and OOM. */ static int too_many_isolated(struct zone *zone, int file, - struct scan_control *sc, int safe) + struct scan_control *sc) { if (current_is_kswapd()) return 0; @@ -1443,12 +1443,14 @@ static int too_many_isolated(struct zone *zone, int file, if (!global_reclaim(sc)) return 0; - if (unlikely(__too_many_isolated(zone, file, sc, 0))) { - if (safe) - return __too_many_isolated(zone, file, sc, safe); - else - return 1; - } + /* + * __too_many_isolated(safe=0) is fast but inaccurate, because it + * doesn't account for the vm_stat_diff[] counters. So if it looks + * like too_many_isolated() is about to return true, fall back to the + * slower, more accurate zone_page_state_snapshot(). + */ + if (unlikely(__too_many_isolated(zone, file, sc, 0))) + return __too_many_isolated(zone, file, sc, 1); return 0; } @@ -1540,18 +1542,15 @@ shrink_inactive_list(unsigned long nr_to_scan, struct lruvec *lruvec, unsigned long nr_immediate = 0; isolate_mode_t isolate_mode = 0; int file = is_file_lru(lru); - int safe = 0; struct zone *zone = lruvec_zone(lruvec); struct zone_reclaim_stat *reclaim_stat = &lruvec->reclaim_stat; - while (unlikely(too_many_isolated(zone, file, sc, safe))) { + while (unlikely(too_many_isolated(zone, file, sc))) { congestion_wait(BLK_RW_ASYNC, HZ/10); /* We are about to die and free our memory. Return now. */ if (fatal_signal_pending(current)) return SWAP_CLUSTER_MAX; - - safe = 1; } lru_add_drain(); |