softlockup: minor cleanup, don't check task->state twice
Oleg Nesterov [Sat, 30 Aug 2008 17:08:40 +0000 (21:08 +0400)]
The recent commit 16d9679f33caf7e683471647d1472bfe133d858 changed
check_hung_task() to filter out the TASK_KILLABLE tasks. We can
move this check to the caller which has to test t->state anyway.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Acked-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

kernel/softlockup.c

index 1a07f8c..cb838ee 100644 (file)
@@ -180,10 +180,6 @@ static void check_hung_task(struct task_struct *t, unsigned long now)
        if (t->flags & PF_FROZEN)
                return;
 
-       /* Don't check for tasks waiting on network file systems like NFS */
-       if (t->state & TASK_KILLABLE)
-               return;
-
        if (switch_count != t->last_switch_count || !t->last_switch_timestamp) {
                t->last_switch_count = switch_count;
                t->last_switch_timestamp = now;
@@ -237,7 +233,8 @@ static void check_hung_uninterruptible_tasks(int this_cpu)
        do_each_thread(g, t) {
                if (!--max_count)
                        goto unlock;
-               if (t->state & TASK_UNINTERRUPTIBLE)
+               /* use "==" to skip the TASK_KILLABLE tasks waiting on NFS */
+               if (t->state == TASK_UNINTERRUPTIBLE)
                        check_hung_task(t, now);
        } while_each_thread(g, t);
  unlock: