dc0422c "mm: vmscan: only evict file pages when we have plenty" makes
a point of not going for anonymous memory while there is still enough
inactive cache around.

The check was added only for global reclaim, but it is just as useful
for memory cgroup reclaim.

Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
---
  mm/vmscan.c | 19 ++++++++++---------
  1 file changed, 10 insertions(+), 9 deletions(-)

diff --git a/mm/vmscan.c b/mm/vmscan.c
index 157bb11..3874dcb 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c

@@ -1671,6 +1671,16 @@ static void get_scan_count(struct lruvec *lruvec, struct scan_control *sc,
  		denominator = 1;
  		goto out;
  	}
+	/*
+	 * There is enough inactive page cache, do not reclaim
+	 * anything from the anonymous working set right now.
+	 */
+	if (!inactive_file_is_low(lruvec)) {
+		fraction[0] = 0;
+		fraction[1] = 1;
+		denominator = 1;
+		goto out;
+	}

  	anon  = get_lru_size(lruvec, LRU_ACTIVE_ANON) +
  		get_lru_size(lruvec, LRU_INACTIVE_ANON);

@@ -1688,15 +1698,6 @@ static void get_scan_count(struct lruvec *lruvec, struct scan_control *sc,
  			fraction[1] = 0;
  			denominator = 1;
  			goto out;
-		} else if (!inactive_file_is_low_global(zone)) {
-			/*
-			 * There is enough inactive page cache, do not
-			 * reclaim anything from the working set right now.
-			 */
-			fraction[0] = 0;
-			fraction[1] = 1;
-			denominator = 1;
-			goto out;
  		}
  	}