mm: make get_scan_ratio() safe for memcg
Currently, get_scan_ratio() always calculate the balancing value for
global reclaim and memcg reclaim doesn't use it. Therefore it doesn't
have scan_global_lru() condition.
However, we plan to expand get_scan_ratio() to be usable for memcg too,
latter. Then, The dependency code of global reclaim in the
get_scan_ratio() insert into scan_global_lru() condision explictly.
This patch doesn't have any functional change.
Acked-by: Rik van Riel <riel@redhat.com>
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/vmscan.c b/mm/vmscan.c
index 6827d35..e2b31a5 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -1376,13 +1376,16 @@
zone_nr_pages(zone, sc, LRU_INACTIVE_ANON);
file = zone_nr_pages(zone, sc, LRU_ACTIVE_FILE) +
zone_nr_pages(zone, sc, LRU_INACTIVE_FILE);
- free = zone_page_state(zone, NR_FREE_PAGES);
- /* If we have very few page cache pages, force-scan anon pages. */
- if (unlikely(file + free <= zone->pages_high)) {
- percent[0] = 100;
- percent[1] = 0;
- return;
+ if (scan_global_lru(sc)) {
+ free = zone_page_state(zone, NR_FREE_PAGES);
+ /* If we have very few page cache pages,
+ force-scan anon pages. */
+ if (unlikely(file + free <= zone->pages_high)) {
+ percent[0] = 100;
+ percent[1] = 0;
+ return;
+ }
}
/*