Introduce a per-memory-cgroup oom_score_adj setting. A read-write single value file which exits on non-root cgroups. The default is "0". It will have a similar meaning to a per-process value, available via /proc/<pid>/oom_score_adj. Should be in a range [-1000, 1000]. Signed-off-by: Roman Gushchin <guro@xxxxxx> Cc: Michal Hocko <mhocko@xxxxxxxxxx> Cc: Vladimir Davydov <vdavydov.dev@xxxxxxxxx> Cc: Johannes Weiner <hannes@xxxxxxxxxxx> Cc: Tejun Heo <tj@xxxxxxxxxx> Cc: Tetsuo Handa <penguin-kernel@xxxxxxxxxxxxxxxxxxx> Cc: kernel-team@xxxxxx Cc: cgroups@xxxxxxxxxxxxxxx Cc: linux-doc@xxxxxxxxxxxxxxx Cc: linux-kernel@xxxxxxxxxxxxxxx Cc: linux-mm@xxxxxxxxx --- include/linux/memcontrol.h | 3 +++ mm/memcontrol.c | 36 ++++++++++++++++++++++++++++++++++++ 2 files changed, 39 insertions(+) diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h index c59926c..b84a050 100644 --- a/include/linux/memcontrol.h +++ b/include/linux/memcontrol.h @@ -203,6 +203,9 @@ struct mem_cgroup { /* kill all tasks in the subtree in case of OOM */ bool oom_kill_all_tasks; + /* OOM kill score adjustment */ + short oom_score_adj; + /* handle for "memory.events" */ struct cgroup_file events_file; diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 4face20..e474eba 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -5333,6 +5333,36 @@ static ssize_t memory_oom_kill_all_tasks_write(struct kernfs_open_file *of, return nbytes; } +static int memory_oom_score_adj_show(struct seq_file *m, void *v) +{ + struct mem_cgroup *memcg = mem_cgroup_from_css(seq_css(m)); + short oom_score_adj = memcg->oom_score_adj; + + seq_printf(m, "%d\n", oom_score_adj); + + return 0; +} + +static ssize_t memory_oom_score_adj_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)); + int oom_score_adj; + int err; + + err = kstrtoint(strstrip(buf), 0, &oom_score_adj); + if (err) + return err; + + if (oom_score_adj < OOM_SCORE_ADJ_MIN || + oom_score_adj > OOM_SCORE_ADJ_MAX) + return -EINVAL; + + memcg->oom_score_adj = (short)oom_score_adj; + + return nbytes; +} + static int memory_events_show(struct seq_file *m, void *v) { struct mem_cgroup *memcg = mem_cgroup_from_css(seq_css(m)); @@ -5459,6 +5489,12 @@ static struct cftype memory_files[] = { .write = memory_oom_kill_all_tasks_write, }, { + .name = "oom_score_adj", + .flags = CFTYPE_NOT_ON_ROOT, + .seq_show = memory_oom_score_adj_show, + .write = memory_oom_score_adj_write, + }, + { .name = "events", .flags = CFTYPE_NOT_ON_ROOT, .file_offset = offsetof(struct mem_cgroup, events_file), -- 2.7.4 -- To unsubscribe from this list: send the line "unsubscribe cgroups" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html