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yaml --- r: 257362 b: refs/heads/master c: 3567b59 h: refs/heads/master v: v3
git-mirror · Jul 20, 2011 · c6f620c · c6f620c
1 parent b20771c
commit c6f620c
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Showing 2 changed files with 16 additions and 1 deletion.
diff --git a/[refs] b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: acf92b485cccf028177f46918e045c0c4e80ee10
+refs/heads/master: 3567b59aa80ac4417002bf58e35dce5c777d4164
diff --git a/trunk/mm/vmscan.c b/trunk/mm/vmscan.c
@@ -276,6 +276,21 @@ unsigned long shrink_slab(struct shrink_control *shrink,
 			total_scan = max_pass;
 		}
 
+		/*
+		 * We need to avoid excessive windup on filesystem shrinkers
+		 * due to large numbers of GFP_NOFS allocations causing the
+		 * shrinkers to return -1 all the time. This results in a large
+		 * nr being built up so when a shrink that can do some work
+		 * comes along it empties the entire cache due to nr >>>
+		 * max_pass.  This is bad for sustaining a working set in
+		 * memory.
+		 *
+		 * Hence only allow the shrinker to scan the entire cache when
+		 * a large delta change is calculated directly.
+		 */
+		if (delta < max_pass / 4)
+			total_scan = min(total_scan, max_pass / 2);
+
 		/*
 		 * Avoid risking looping forever due to too large nr value:
 		 * never try to free more than twice the estimate number of