Commit 35cd78156c499ef83f60605e4643d5a98fef14fd
Committed by
Linus Torvalds
1 parent
a731286de6
Exists in
master
and in
39 other branches
vmscan: throttle direct reclaim when too many pages are isolated already
When way too many processes go into direct reclaim, it is possible for all of the pages to be taken off the LRU. One result of this is that the next process in the page reclaim code thinks there are no reclaimable pages left and triggers an out of memory kill. One solution to this problem is to never let so many processes into the page reclaim path that the entire LRU is emptied. Limiting the system to only having half of each inactive list isolated for reclaim should be safe. Signed-off-by: Rik van Riel <riel@redhat.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Wu Fengguang <fengguang.wu@intel.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Showing 1 changed file with 33 additions and 0 deletions Side-by-side Diff
mm/vmscan.c
... | ... | @@ -1034,6 +1034,31 @@ |
1034 | 1034 | } |
1035 | 1035 | |
1036 | 1036 | /* |
1037 | + * Are there way too many processes in the direct reclaim path already? | |
1038 | + */ | |
1039 | +static int too_many_isolated(struct zone *zone, int file, | |
1040 | + struct scan_control *sc) | |
1041 | +{ | |
1042 | + unsigned long inactive, isolated; | |
1043 | + | |
1044 | + if (current_is_kswapd()) | |
1045 | + return 0; | |
1046 | + | |
1047 | + if (!scanning_global_lru(sc)) | |
1048 | + return 0; | |
1049 | + | |
1050 | + if (file) { | |
1051 | + inactive = zone_page_state(zone, NR_INACTIVE_FILE); | |
1052 | + isolated = zone_page_state(zone, NR_ISOLATED_FILE); | |
1053 | + } else { | |
1054 | + inactive = zone_page_state(zone, NR_INACTIVE_ANON); | |
1055 | + isolated = zone_page_state(zone, NR_ISOLATED_ANON); | |
1056 | + } | |
1057 | + | |
1058 | + return isolated > inactive; | |
1059 | +} | |
1060 | + | |
1061 | +/* | |
1037 | 1062 | * shrink_inactive_list() is a helper for shrink_zone(). It returns the number |
1038 | 1063 | * of reclaimed pages |
1039 | 1064 | */ |
... | ... | @@ -1047,6 +1072,14 @@ |
1047 | 1072 | unsigned long nr_reclaimed = 0; |
1048 | 1073 | struct zone_reclaim_stat *reclaim_stat = get_reclaim_stat(zone, sc); |
1049 | 1074 | int lumpy_reclaim = 0; |
1075 | + | |
1076 | + while (unlikely(too_many_isolated(zone, file, sc))) { | |
1077 | + congestion_wait(WRITE, HZ/10); | |
1078 | + | |
1079 | + /* We are about to die and free our memory. Return now. */ | |
1080 | + if (fatal_signal_pending(current)) | |
1081 | + return SWAP_CLUSTER_MAX; | |
1082 | + } | |
1050 | 1083 | |
1051 | 1084 | /* |
1052 | 1085 | * If we need a large contiguous chunk of memory, or have |