oom: /proc/<pid>/oom_score treat kernel thread honestly
If a kernel thread is using use_mm(), badness() returns a positive value.
This is not a big issue because caller take care of it correctly. But
there is one exception, /proc/<pid>/oom_score calls badness() directly and
doesn't care that the task is a regular process.
Another example, /proc/1/oom_score return !0 value. But it's unkillable.
This incorrectness makes administration a little confusing.
This patch fixes it.
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: David Rientjes <rientjes@google.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/fs/proc/base.c b/fs/proc/base.c
index acb7ef8..fc23f62 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -428,7 +428,8 @@
#endif
/* The badness from the OOM killer */
-unsigned long badness(struct task_struct *p, unsigned long uptime);
+unsigned long badness(struct task_struct *p, struct mem_cgroup *mem,
+ nodemask_t *nodemask, unsigned long uptime);
static int proc_oom_score(struct task_struct *task, char *buffer)
{
unsigned long points = 0;
@@ -437,7 +438,7 @@
do_posix_clock_monotonic_gettime(&uptime);
read_lock(&tasklist_lock);
if (pid_alive(task))
- points = badness(task, uptime.tv_sec);
+ points = badness(task, NULL, NULL, uptime.tv_sec);
read_unlock(&tasklist_lock);
return sprintf(buffer, "%lu\n", points);
}