From: Greg KH <gre...@linuxfoundation.org>
3.0-stable review patch. If anyone has any objections, please let me know.
------------------
From: Johannes Weiner <jwei...@redhat.com>
commit a4d3e9e76337059406fcf3ead288c0df22a790e9 upstream.
Stable note: Not tracked in Bugzilla. This patch augments an earlier commit
that avoids scanning priority being artificially raised. The older
fix was particularly important for small memcgs to avoid calling
wait_iff_congested() unnecessarily.
Without swap, anonymous pages are not scanned. As such, they should not
count when considering force-scanning a small target if there is no swap.
Otherwise, targets are not force-scanned even when their effective scan
number is zero and the other conditions--kswapd/memcg--apply.
This fixes 246e87a93934 ("memcg: fix get_scan_count() for small
targets").
[a...@linux-foundation.org: fix comment]
Signed-off-by: Johannes Weiner <jwei...@redhat.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hir...@jp.fujitsu.com>
Reviewed-by: Michal Hocko <mho...@suse.cz>
Cc: Ying Han <ying...@google.com>
Cc: Balbir Singh <bsinghar...@gmail.com>
Cc: KOSAKI Motohiro <kosaki.motoh...@jp.fujitsu.com>
Cc: Daisuke Nishimura <nishim...@mxp.nes.nec.co.jp>
Acked-by: Mel Gorman <m...@csn.ul.ie>
Signed-off-by: Andrew Morton <a...@linux-foundation.org>
Signed-off-by: Linus Torvalds <torva...@linux-foundation.org>
Signed-off-by: Mel Gorman <mgor...@suse.de>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>
---
mm/vmscan.c | 27 ++++++++++++---------------
1 file changed, 12 insertions(+), 15 deletions(-)
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -1747,23 +1747,15 @@ static void get_scan_count(struct zone *
u64 fraction[2], denominator;
enum lru_list l;
int noswap = 0;
- int force_scan = 0;
+ bool force_scan = false;
unsigned long nr_force_scan[2];
-
- anon = zone_nr_lru_pages(zone, sc, LRU_ACTIVE_ANON) +
- zone_nr_lru_pages(zone, sc, LRU_INACTIVE_ANON);
- file = zone_nr_lru_pages(zone, sc, LRU_ACTIVE_FILE) +
- zone_nr_lru_pages(zone, sc, LRU_INACTIVE_FILE);
-
- if (((anon + file) >> priority) < SWAP_CLUSTER_MAX) {
- /* kswapd does zone balancing and need to scan this zone */
- if (scanning_global_lru(sc) && current_is_kswapd())
- force_scan = 1;
- /* memcg may have small limit and need to avoid priority drop */
- if (!scanning_global_lru(sc))
- force_scan = 1;
- }
+ /* kswapd does zone balancing and needs to scan this zone */
+ if (scanning_global_lru(sc) && current_is_kswapd())
+ force_scan = true;
+ /* memcg may have small limit and need to avoid priority drop */
+ if (!scanning_global_lru(sc))
+ force_scan = true;
/* If we have no swap space, do not bother scanning anon pages. */
if (!sc->may_swap || (nr_swap_pages <= 0)) {
@@ -1776,6 +1768,11 @@ static void get_scan_count(struct zone *
goto out;
}
+ anon = zone_nr_lru_pages(zone, sc, LRU_ACTIVE_ANON) +
+ zone_nr_lru_pages(zone, sc, LRU_INACTIVE_ANON);
+ file = zone_nr_lru_pages(zone, sc, LRU_ACTIVE_FILE) +
+ zone_nr_lru_pages(zone, sc, LRU_INACTIVE_FILE);
+
if (scanning_global_lru(sc)) {
free = zone_page_state(zone, NR_FREE_PAGES);
/* If we have very few page cache pages,
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
