2008-08-30 17:03:53

by Oleg Nesterov

[permalink] [raw]
Subject: [PATCH] softlockup: minor cleanup, don't check task->state twice

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 <[email protected]>

--- 2.6.27-rc4/kernel/softlockup.c~SOFTLOCKUP 2008-08-30 18:24:40.000000000 +0400
+++ 2.6.27-rc4/kernel/softlockup.c 2008-08-30 21:06:51.000000000 +0400
@@ -180,10 +180,6 @@ static void check_hung_task(struct task_
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_t
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: