It is a bit annoying that do_exit() takes ->pi_lock to set PF_EXITING.
All we need is to synchronize with lookup_pi_state() which saw this task
without PF_EXITING under ->pi_lock.
Change do_exit() to use spin_unlock_wait().
Signed-off-by: Oleg Nesterov <[EMAIL PROTECTED]>
Acked-by: Ingo Molnar <[EMAIL PROTECTED]>
--- t/kernel/exit.c~PF_EXIT 2007-06-19 17:09:15.000000000 +0400
+++ t/kernel/exit.c 2007-07-21 15:34:13.000000000 +0400
@@ -908,13 +908,13 @@ fastcall NORET_TYPE void do_exit(long co
schedule();
}
+ tsk->flags |= PF_EXITING;
/*
* tsk->flags are checked in the futex code to protect against
* an exiting task cleaning up the robust pi futexes.
*/
- spin_lock_irq(&tsk->pi_lock);
- tsk->flags |= PF_EXITING;
- spin_unlock_irq(&tsk->pi_lock);
+ smp_mb();
+ spin_unlock_wait(&tsk->pi_lock);
if (unlikely(in_atomic()))
printk(KERN_INFO "note: %s[%d] exited with preempt_count %d\n",
-
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/
