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 <[email protected]>
Cc: Minchan Kim <[email protected]>
Cc: David Rientjes <[email protected]>
Cc: KAMEZAWA Hiroyuki <[email protected]>
Cc: Oleg Nesterov <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
This commit is contained in:
KOSAKI Motohiro 2010-08-09 17:19:37 -07:00 • committed by Linus Torvalds
commit 26ebc98491
2 changed files with 10 additions and 8 deletions

View file

@ -428,7 +428,8 @@ static const struct file_operations proc_lstats_operations = {
#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 @@ static int proc_oom_score(struct task_struct *task, char *buffer)
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);
}