From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pl0-f69.google.com (mail-pl0-f69.google.com [209.85.160.69]) by kanga.kvack.org (Postfix) with ESMTP id 8EC306B000D for ; Mon, 11 Jun 2018 13:55:15 -0400 (EDT) Received: by mail-pl0-f69.google.com with SMTP id 39-v6so1054879ple.6 for ; Mon, 11 Jun 2018 10:55:15 -0700 (PDT) Received: from mx0b-00082601.pphosted.com (mx0b-00082601.pphosted.com. [67.231.153.30]) by mx.google.com with ESMTPS id q15-v6si38652432pls.358.2018.06.11.10.55.13 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 11 Jun 2018 10:55:14 -0700 (PDT) From: Roman Gushchin Subject: [PATCH v2 2/3] mm, memcg: propagate memory effective protection on setting memory.min/low Date: Mon, 11 Jun 2018 10:54:17 -0700 Message-ID: <20180611175418.7007-3-guro@fb.com> In-Reply-To: <20180611175418.7007-1-guro@fb.com> References: <20180611175418.7007-1-guro@fb.com> MIME-Version: 1.0 Content-Type: text/plain Sender: owner-linux-mm@kvack.org List-ID: To: Andrew Morton Cc: Johannes Weiner , Michal Hocko , Tejun Heo , linux-mm@kvack.org, kernel-team@fb.com, linux-kernel@vger.kernel.org, Roman Gushchin , Vladimir Davydov , Greg Thelen , Shuah Khan , Andrew Morton Explicitly propagate effective memory min/low values down by the tree. If there is the global memory pressure, it's not really necessary. Effective memory guarantees will be propagated automatically as we traverse memory cgroup tree in the reclaim path. But if there is no global memory pressure, effective memory protection still matters for local (memcg-scoped) memory pressure. So, we have to update effective limits in the subtree, if a user changes memory.min and memory.low values. Link: http://lkml.kernel.org/r/20180522132528.23769-1-guro@fb.com Signed-off-by: Roman Gushchin Cc: Johannes Weiner Cc: Michal Hocko Cc: Vladimir Davydov Cc: Greg Thelen Cc: Tejun Heo Cc: Shuah Khan Signed-off-by: Andrew Morton --- mm/memcontrol.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 5a3873e9d657..485df6f63d26 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -5084,7 +5084,7 @@ static int memory_min_show(struct seq_file *m, void *v) static ssize_t memory_min_write(struct kernfs_open_file *of, char *buf, size_t nbytes, loff_t off) { - struct mem_cgroup *memcg = mem_cgroup_from_css(of_css(of)); + struct mem_cgroup *iter, *memcg = mem_cgroup_from_css(of_css(of)); unsigned long min; int err; @@ -5095,6 +5095,11 @@ static ssize_t memory_min_write(struct kernfs_open_file *of, page_counter_set_min(&memcg->memory, min); + rcu_read_lock(); + for_each_mem_cgroup_tree(iter, memcg) + mem_cgroup_protected(NULL, iter); + rcu_read_unlock(); + return nbytes; } @@ -5114,7 +5119,7 @@ static int memory_low_show(struct seq_file *m, void *v) static ssize_t memory_low_write(struct kernfs_open_file *of, char *buf, size_t nbytes, loff_t off) { - struct mem_cgroup *memcg = mem_cgroup_from_css(of_css(of)); + struct mem_cgroup *iter, *memcg = mem_cgroup_from_css(of_css(of)); unsigned long low; int err; @@ -5125,6 +5130,11 @@ static ssize_t memory_low_write(struct kernfs_open_file *of, page_counter_set_low(&memcg->memory, low); + rcu_read_lock(); + for_each_mem_cgroup_tree(iter, memcg) + mem_cgroup_protected(NULL, iter); + rcu_read_unlock(); + return nbytes; } -- 2.14.4