3.0 patches

2 files changed, 117 insertions, 0 deletions

diff --git a/queue-3.0/memcg-fix-vmscan-count-in-small-memcgs.patch b/queue-3.0/memcg-fix-vmscan-count-in-small-memcgs.patch
new file mode 100644
index 0000000000..e4a8fed904
--- /dev/null
+++ b/queue-3.0/memcg-fix-vmscan-count-in-small-memcgs.patch
@@ -0,0 +1,116 @@
+From 4508378b9523e22a2a0175d8bf64d932fb10a67d Mon Sep 17 00:00:00 2001
+From: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
+Date: Tue, 26 Jul 2011 16:08:24 -0700
+Subject: memcg: fix vmscan count in small memcgs
+
+From: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
+
+commit 4508378b9523e22a2a0175d8bf64d932fb10a67d upstream.
+
+Commit 246e87a93934 ("memcg: fix get_scan_count() for small targets")
+fixes the memcg/kswapd behavior against small targets and prevent vmscan
+priority too high.
+
+But the implementation is too naive and adds another problem to small
+memcg.  It always force scan to 32 pages of file/anon and doesn't handle
+swappiness and other rotate_info.  It makes vmscan to scan anon LRU
+regardless of swappiness and make reclaim bad.  This patch fixes it by
+adjusting scanning count with regard to swappiness at el.
+
+At a test "cat 1G file under 300M limit." (swappiness=20)
+ before patch
+        scanned_pages_by_limit 360919
+        scanned_anon_pages_by_limit 180469
+        scanned_file_pages_by_limit 180450
+        rotated_pages_by_limit 31
+        rotated_anon_pages_by_limit 25
+        rotated_file_pages_by_limit 6
+        freed_pages_by_limit 180458
+        freed_anon_pages_by_limit 19
+        freed_file_pages_by_limit 180439
+        elapsed_ns_by_limit 429758872
+ after patch
+        scanned_pages_by_limit 180674
+        scanned_anon_pages_by_limit 24
+        scanned_file_pages_by_limit 180650
+        rotated_pages_by_limit 35
+        rotated_anon_pages_by_limit 24
+        rotated_file_pages_by_limit 11
+        freed_pages_by_limit 180634
+        freed_anon_pages_by_limit 0
+        freed_file_pages_by_limit 180634
+        elapsed_ns_by_limit 367119089
+        scanned_pages_by_system 0
+
+the numbers of scanning anon are decreased(as expected), and elapsed time
+reduced. By this patch, small memcgs will work better.
+(*) Because the amount of file-cache is much bigger than anon,
+    recalaim_stat's rotate-scan counter make scanning files more.
+
+Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
+Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
+Cc: Michal Hocko <mhocko@suse.cz>
+Cc: Ying Han <yinghan@google.com>
+Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
+Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
+Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
+
+---
+ mm/vmscan.c |   18 ++++++++++++------
+ 1 file changed, 12 insertions(+), 6 deletions(-)
+
+--- a/mm/vmscan.c
++++ b/mm/vmscan.c
+@@ -1748,6 +1748,7 @@ static void get_scan_count(struct zone *
+ 	enum lru_list l;
+ 	int noswap = 0;
+ 	int force_scan = 0;
++	unsigned long nr_force_scan[2];
+ 
+ 
+ 	anon  = zone_nr_lru_pages(zone, sc, LRU_ACTIVE_ANON) +
+@@ -1770,6 +1771,8 @@ static void get_scan_count(struct zone *
+ 		fraction[0] = 0;
+ 		fraction[1] = 1;
+ 		denominator = 1;
++		nr_force_scan[0] = 0;
++		nr_force_scan[1] = SWAP_CLUSTER_MAX;
+ 		goto out;
+ 	}
+ 
+@@ -1781,6 +1784,8 @@ static void get_scan_count(struct zone *
+ 			fraction[0] = 1;
+ 			fraction[1] = 0;
+ 			denominator = 1;
++			nr_force_scan[0] = SWAP_CLUSTER_MAX;
++			nr_force_scan[1] = 0;
+ 			goto out;
+ 		}
+ 	}
+@@ -1829,6 +1834,11 @@ static void get_scan_count(struct zone *
+ 	fraction[0] = ap;
+ 	fraction[1] = fp;
+ 	denominator = ap + fp + 1;
++	if (force_scan) {
++		unsigned long scan = SWAP_CLUSTER_MAX;
++		nr_force_scan[0] = div64_u64(scan * ap, denominator);
++		nr_force_scan[1] = div64_u64(scan * fp, denominator);
++	}
+ out:
+ 	for_each_evictable_lru(l) {
+ 		int file = is_file_lru(l);
+@@ -1849,12 +1859,8 @@ out:
+ 		 * memcg, priority drop can cause big latency. So, it's better
+ 		 * to scan small amount. See may_noscan above.
+ 		 */
+-		if (!scan && force_scan) {
+-			if (file)
+-				scan = SWAP_CLUSTER_MAX;
+-			else if (!noswap)
+-				scan = SWAP_CLUSTER_MAX;
+-		}
++		if (!scan && force_scan)
++			scan = nr_force_scan[file];
+ 		nr[l] = scan;
+ 	}
+ }
diff --git a/queue-3.0/series b/queue-3.0/series
index 21713ef525..d7e3cde1d4 100644
--- a/queue-3.0/series
+++ b/queue-3.0/series
@@ -227,3 +227,4 @@ asoc-ssm2602-re-enable-oscillator-after-suspend.patch
 alsa-hda-realtek-avoid-bogus-hp-pin-assignment.patch
 alsa-hda-no-power-nids-on-92hd93.patch
 alsa-usb-audio-check-for-possible-chip-null-pointer-before-clearing-probing-flag.patch
+memcg-fix-vmscan-count-in-small-memcgs.patch