On 08/23/2012 07:07 PM, Ying Han wrote:
On Thu, Aug 16, 2012 at 8:38 AM, Rik van Riel <riel@xxxxxxxxxx <mailto:riel@xxxxxxxxxx>> wrote: When a lot of streaming file IO is happening, it makes sense to evict just the inactive file pages and leave the other LRU lists alone. Likewise, when driving a cgroup hierarchy into its hard limit, or over its soft limit, it makes sense to pick a child cgroup that has lots of inactive file pages, and evict those first. Being over its soft limit is considered a stronger preference than just having a lot of inactive file pages, so a well behaved cgroup is allowed to keep its file cache when there is a "badly behaving" one in the same hierarchy. Signed-off-by: Rik van Riel <riel@xxxxxxxxxx <mailto:riel@xxxxxxxxxx>> --- mm/vmscan.c | 37 +++++++++++++++++++++++++++++++++---- 1 files changed, 33 insertions(+), 4 deletions(-) diff --git a/mm/vmscan.c b/mm/vmscan.c index 769fdcd..2884b4f 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -1576,6 +1576,19 @@ static int inactive_list_is_low(struct lruvec *lruvec, enum lru_list lru) return inactive_anon_is_low(lruvec); } +/* If this lruvec has lots of inactive file pages, reclaim those only. */ +static bool reclaim_file_only(struct lruvec *lruvec, struct scan_control *sc, + unsigned long anon, unsigned long file) +{ + if (inactive_file_is_low(lruvec)) + return false; + + if (file > (anon + file) >> sc->priority) + return true; + + return false; +} + static unsigned long shrink_list(enum lru_list lru, unsigned long nr_to_scan, struct lruvec *lruvec, struct scan_control *sc) { @@ -1658,6 +1671,14 @@ static void get_scan_count(struct lruvec *lruvec, struct scan_control *sc, } } + /* Lots of inactive file pages? Reclaim those only. */ + if (reclaim_file_only(lruvec, sc, anon, file)) { + fraction[0] = 0; + fraction[1] = 1; + denominator = 1; + goto out; + } + /* * With swappiness at 100, anonymous and file have the same priority. * This scanning priority is essentially the inverse of IO cost. @@ -1922,8 +1943,8 @@ static void age_recent_pressure(struct lruvec *lruvec, struct zone *zone) * should always be larger than recent_rotated, and the size should * always be larger than recent_pressure. */ -static u64 reclaim_score(struct mem_cgroup *memcg, - struct lruvec *lruvec) +static u64 reclaim_score(struct mem_cgroup *memcg, struct lruvec *lruvec, + struct scan_control *sc) { struct zone_reclaim_stat *reclaim_stat = &lruvec->reclaim_stat; u64 anon, file; @@ -1949,6 +1970,14 @@ static u64 reclaim_score(struct mem_cgroup *memcg, anon *= 10000; } + /* + * Prefer reclaiming from an lruvec with lots of inactive file + * pages. Once those have been reclaimed, the score will drop so + * far we will pick another lruvec to reclaim from. + */ + if (reclaim_file_only(lruvec, sc, anon, file)) + file *= 100; + return max(anon, file); } @@ -1977,7 +2006,7 @@ static void shrink_zone(struct zone *zone, struct scan_control *sc) age_recent_pressure(lruvec, zone); - score = reclaim_score(memcg, lruvec); + score = reclaim_score(memcg, lruvec, sc); /* Pick the lruvec with the highest score. */ if (score > max_score) { @@ -2002,7 +2031,7 @@ static void shrink_zone(struct zone *zone, struct scan_control *sc) */ do { shrink_lruvec(victim_lruvec, sc); - score = reclaim_score(memcg, victim_lruvec); + score = reclaim_score(memcg, victim_lruvec, sc); I wonder if you meant s/memcg/victim_memcg here.
You are totally right, that should be victim_memcg. Time for me to get a tree that works here, and where my patches will apply. I got the c-state governor patches sent out for KS, now I should be able to get some time again for cgroups stuff :) -- All rights reversed -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>