oom: improve commentary in dump_tasks()

The comments in dump_tasks() should be updated to be more clear about why
tasks are filtered and how they are filtered by its argument.

An unnecessary comment concerning a check for is_global_init() is removed
since it isn't of importance.

Suggested-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: David Rientjes <rientjes@google.com>
Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Balbir Singh <balbir@in.ibm.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/mm/oom_kill.c b/mm/oom_kill.c
index 5285da9a9c1a083412a5dd31e52307d58c319584..ef4ed4ae6f64b7bd5d37843040c283c2d39dcf77 100644 (file)
--- a/mm/oom_kill.c
+++ b/mm/oom_kill.c
@@ -323,7 +323,7 @@ static struct task_struct *select_bad_process(unsigned long *ppoints,
 
 /**
  * dump_tasks - dump current memory state of all system tasks
- * @mem: target memory controller
+ * @mem: current's memory controller, if constrained
  *
  * Dumps the current memory state of all system tasks, excluding kernel threads.
  * State information includes task's pid, uid, tgid, vm size, rss, cpu, oom_adj
@@ -342,11 +342,6 @@ static void dump_tasks(const struct mem_cgroup *mem)
        printk(KERN_INFO "[ pid ]   uid  tgid total_vm      rss cpu oom_adj "
               "name\n");
        for_each_process(p) {
-               /*
-                * We don't have is_global_init() check here, because the old
-                * code do that. printing init process is not big matter. But
-                * we don't hope to make unnecessary compatibility breaking.
-                */
                if (p->flags & PF_KTHREAD)
                        continue;
                if (mem && !task_in_mem_cgroup(p, mem))
@@ -355,8 +350,8 @@ static void dump_tasks(const struct mem_cgroup *mem)
                task = find_lock_task_mm(p);
                if (!task) {
                        /*
-                        * Probably oom vs task-exiting race was happen and ->mm
-                        * have been detached. thus there's no need to report
+                        * This is a kthread or all of p's threads have already
+                        * detached their mm's.  There's no need to report
                         * them; they can't be oom killed anyway.
                         */
                        continue;