diff options
| author | Roman Gushchin <guro@fb.com> | 2018-04-23 08:20:29 +1000 |
|---|---|---|
| committer | Stephen Rothwell <sfr@canb.auug.org.au> | 2018-04-23 08:23:48 +1000 |
| commit | 759183beffa88f9fbcb7248f023a8da11a51eafa (patch) | |
| tree | ba2b706ca8103025d4de00c29fdeb9be6952e9c6 | |
| parent | 82bce23c515d9d6614f2c4e2b044796e9a70fde7 (diff) | |
| download | linux-759183beffa88f9fbcb7248f023a8da11a51eafa.tar.gz linux-759183beffa88f9fbcb7248f023a8da11a51eafa.tar.xz | |
mm, oom: return error on access to memory.oom_group if groupoom is disabled
Cgroup-aware OOM killer depends on cgroup mount option and is turned off
by default, despite the user interface (memory.oom_group file) is always
present. As it might be confusing to a user, let's return -ENOTSUPP on an
attempt to access to memory.oom_group if groupoom is not enabled globally.
Example:
$ cd /sys/fs/cgroup/user.slice/
$ cat memory.oom_group
cat: memory.oom_group: Unknown error 524
$ echo 1 > memory.oom_group
-bash: echo: write error: Unknown error 524
$ mount -o remount,groupoom /sys/fs/cgroup
$ echo 1 > memory.oom_group
$ cat memory.oom_group
1
Link: http://lkml.kernel.org/r/20171201170004.GA27436@castle.DHCP.thefacebook.com
Signed-off-by: Roman Gushchin <guro@fb.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
| -rw-r--r-- | mm/memcontrol.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/mm/memcontrol.c b/mm/memcontrol.c index dfd763c3ec71..c35c8d650c44 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -5430,6 +5430,9 @@ static int memory_oom_group_show(struct seq_file *m, void *v) struct mem_cgroup *memcg = mem_cgroup_from_css(seq_css(m)); bool oom_group = memcg->oom_group; + if (!(cgrp_dfl_root.flags & CGRP_GROUP_OOM)) + return -ENOTSUPP; + seq_printf(m, "%d\n", oom_group); return 0; @@ -5443,6 +5446,9 @@ static ssize_t memory_oom_group_write(struct kernfs_open_file *of, int oom_group; int err; + if (!(cgrp_dfl_root.flags & CGRP_GROUP_OOM)) + return -ENOTSUPP; + err = kstrtoint(strstrip(buf), 0, &oom_group); if (err) return err; |