[PATCH] oom: don't kill unkillable children or siblings

Abort the kill if any of our threads have OOM_DISABLE set.  Having this
test here also prevents any OOM_DISABLE child of the "selected" process
from being killed.

Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

diff --git a/mm/oom_kill.c b/mm/oom_kill.c
index 2e3ce3a..bc2627d 100644 (file)
--- a/mm/oom_kill.c
+++ b/mm/oom_kill.c
@@ -313,15 +313,24 @@ static int oom_kill_task(struct task_struct *p, const char *message)
        if (mm == NULL)
                return 1;
 
+       /*
+        * Don't kill the process if any threads are set to OOM_DISABLE
+        */
+       do_each_thread(g, q) {
+               if (q->mm == mm && p->oomkilladj == OOM_DISABLE)
+                       return 1;
+       } while_each_thread(g, q);
+
        __oom_kill_task(p, message);
+
        /*
         * kill all processes that share the ->mm (i.e. all threads),
         * but are in a different thread group
         */
-       do_each_thread(g, q)
+       do_each_thread(g, q) {
                if (q->mm == mm && q->tgid != p->tgid)
                        __oom_kill_task(q, message);
-       while_each_thread(g, q);
+       } while_each_thread(g, q);
 
        return 0;
 }