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yaml --- r: 347038 b: refs/heads/master c: d37dd5d h: refs/heads/master v: v3
git-mirror · Dec 18, 2012 · ee91053 · ee91053
1 parent 52545e9
commit ee91053
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Showing 2 changed files with 6 additions and 2 deletions.
diff --git a/[refs] b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: dc053733ea44babedb20266300b984d6add8b9e5
+refs/heads/master: d37dd5dcb955dd8c2cdd4eaef1f15d1b7ecbc379
diff --git a/trunk/mm/vmscan.c b/trunk/mm/vmscan.c
@@ -1177,7 +1177,11 @@ int isolate_lru_page(struct page *page)
 }
 
 /*
- * Are there way too many processes in the direct reclaim path already?
+ * A direct reclaimer may isolate SWAP_CLUSTER_MAX pages from the LRU list and
+ * then get resheduled. When there are massive number of tasks doing page
+ * allocation, such sleeping direct reclaimers may keep piling up on each CPU,
+ * the LRU list will go small and be scanned faster than necessary, leading to
+ * unnecessary swapping, thrashing and OOM.
  */
 static int too_many_isolated(struct zone *zone, int file,
 		struct scan_control *sc)