schedule() checks PF_DEAD on every context switch, and sets ->state = EXIT_DEAD
to ensure that exited task will be deactivated.
I think it is better to set EXIT_DEAD in do_exit(), along with PF_DEAD flag.
It is safe to do without task_rq() locking, because concurrent try_to_wake_up()
can't change task's ->state: the 'state' argument of try_to_wake_up() can't have
EXIT_DEAD bit. And in case when try_to_wake_up() sees stale value of ->state ==
TASK_RUNNING it will do nothing.
Signed-off-by: Oleg Nesterov <[email protected]>
--- 2.6.15-rc2/kernel/exit.c~4_DEAD 2005-11-23 19:33:27.000000000 +0300
+++ 2.6.15-rc2/kernel/exit.c 2005-11-24 19:14:29.000000000 +0300
@@ -875,6 +875,7 @@ fastcall NORET_TYPE void do_exit(long co
preempt_disable();
BUG_ON(tsk->flags & PF_DEAD);
tsk->flags |= PF_DEAD;
+ tsk->state = EXIT_DEAD;
schedule();
BUG();
--- 2.6.15-rc2/kernel/sched.c~4_DEAD 2005-11-22 19:35:52.000000000 +0300
+++ 2.6.15-rc2/kernel/sched.c 2005-11-24 19:13:34.000000000 +0300
@@ -3000,9 +3000,6 @@ need_resched_nonpreemptible:
spin_lock_irq(&rq->lock);
- if (unlikely(prev->flags & PF_DEAD))
- prev->state = EXIT_DEAD;
-
switch_count = &prev->nivcsw;
if (prev->state && !(preempt_count() & PREEMPT_ACTIVE)) {
switch_count = &prev->nvcsw;
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
[Index of Archives]
[Kernel Newbies]
[Netfilter]
[Bugtraq]
[Photo]
[Stuff]
[Gimp]
[Yosemite News]
[MIPS Linux]
[ARM Linux]
[Linux Security]
[Linux RAID]
[Video 4 Linux]
[Linux for the blind]
[Linux Resources]
