Re: [RFC][PATCH 3/4] memcg: softlimit caller via kswapd

[KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>]

Hi Balbir-san,

> Looks like a dirty hack, replacing sc-> fields this way. I've
> experimented a lot with per zone balancing and soft limits and it does
> not work well. The reasons
> 
> 1. zone watermark balancing has a different goal than soft limit. Soft
> limits are more of a mem cgroup feature rather than node/zone feature.
> IIRC, you called reclaim as hot-path for soft limit reclaim, my
> experimentation is beginning to show changed behaviour
> 
> On a system with 4 CPUs and 4 Nodes, I find all CPUs spending time
> doing reclaim, putting the hook in the reclaim path, makes the reclaim
> dependent on the number of tasks and contention.
> 
> What does your test data/experimentation show?

you pointed out mainline kernel bug, not kamezawa patch's bug ;-)
Could you please try following patch?

sorry, this is definitly my fault.


---
 mm/vmscan.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/mm/vmscan.c b/mm/vmscan.c
index bfd853b..15f7737 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -1470,7 +1470,7 @@ static void shrink_zone(int priority, struct zone *zone,
 		int file = is_file_lru(l);
 		int scan;
 
-		scan = zone_page_state(zone, NR_LRU_BASE + l);
+		scan = zone_nr_pages(zone, sc, l);
 		if (priority) {
 			scan >>= priority;
 			scan = (scan * percent[file]) / 100;
-- 
1.6.0.6



--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org.  For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>