From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx182.postini.com [74.125.245.182]) by kanga.kvack.org (Postfix) with SMTP id 086696B0037 for ; Fri, 26 Jul 2013 12:04:31 -0400 (EDT) From: Michal Hocko Subject: [PATCH v5.1 6/8] memcg, vmscan: Do not attempt soft limit reclaim if it would not scan anything Date: Fri, 26 Jul 2013 18:04:16 +0200 Message-Id: <1374854658-26990-7-git-send-email-mhocko@suse.cz> In-Reply-To: <1374854658-26990-1-git-send-email-mhocko@suse.cz> References: <1374854658-26990-1-git-send-email-mhocko@suse.cz> Sender: owner-linux-mm@kvack.org List-ID: To: Andrew Morton , Johannes Weiner , KAMEZAWA Hiroyuki Cc: linux-mm@kvack.org, cgroups@vger.kernel.org, linux-kernel@vger.kernel.org, Ying Han , Hugh Dickins , Michel Lespinasse , Greg Thelen , KOSAKI Motohiro , Tejun Heo , Balbir Singh , Glauber Costa mem_cgroup_should_soft_reclaim controls whether soft reclaim pass is done and it always says yes currently. Memcg iterators are clever to skip nodes that are not soft reclaimable quite efficiently but mem_cgroup_should_soft_reclaim can be more clever and do not start the soft reclaim pass at all if it knows that nothing would be scanned anyway. In order to do that, simply reuse mem_cgroup_soft_reclaim_eligible for the target group of the reclaim and allow the pass only if the whole subtree wouldn't be skipped. Changes since v1 - do not export mem_cgroup_root and teach mem_cgroup_soft_reclaim_eligible to handle NULL memcg as mem_cgroup_root Signed-off-by: Michal Hocko --- mm/memcontrol.c | 6 +++++- mm/vmscan.c | 4 +++- 2 files changed, 8 insertions(+), 2 deletions(-) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index c1be265..8629ca6 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -1909,7 +1909,11 @@ enum mem_cgroup_filter_t mem_cgroup_soft_reclaim_eligible(struct mem_cgroup *memcg, struct mem_cgroup *root) { - struct mem_cgroup *parent = memcg; + struct mem_cgroup *parent; + + if (!memcg) + memcg = root_mem_cgroup; + parent = memcg; if (res_counter_soft_limit_excess(&memcg->res)) return VISIT; diff --git a/mm/vmscan.c b/mm/vmscan.c index e03494a..b45ff5b 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -142,7 +142,9 @@ static bool global_reclaim(struct scan_control *sc) static bool mem_cgroup_should_soft_reclaim(struct scan_control *sc) { - return !mem_cgroup_disabled(); + struct mem_cgroup *root = sc->target_mem_cgroup; + return !mem_cgroup_disabled() && + mem_cgroup_soft_reclaim_eligible(root, root) != SKIP_TREE; } #else static bool global_reclaim(struct scan_control *sc) -- 1.8.3.2 -- 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: email@kvack.org