Re: [BProc] Re: deadlock with 2.4.21/3.2.6

[Nicholas H. <he...@se...>]

On Tue, 2003-10-21 at 11:54, er...@he... wrote:
> I got an oops out of the NMI watchdog which was enlightening (or at
> least indicated which code was at fault).  The following patch may
> have fixed it for me.  I say "may have" since I've had some trouble
> reproducing the problem reliably.
> 
> This patch turns off "sigbypass" which is a little optimization where
> a process sending a signal to a ghost doesn't bother the ghost.
> Instead it just throws a signal forwarding message right on the
> message queue.  I'm not sure how the code is broken.  I haven't had
> time to look into it yet.
> 
> Please give it a try and let me know if you still see the deadlock.
> 
> 
> --- hooks.c	29 Aug 2003 21:46:57 -0000	1.53
> +++ hooks.c	21 Oct 2003 15:41:44 -0000
> @@ -314,6 +314,11 @@
>       * t->sigmask */
>      struct bproc_krequest_t *req;
>      struct siginfo           tmpinfo;
> +
> +    return 0;			/* XXX disable sigbypass for now.
> +				 * There seems to be something busted or
> +				 * unsafe about this code... */
> +
>      if (!BPROC_ISGHOST(t) || !t->bproc.ghost->sigbypass)
>  	return 0;

Well, that seems to have worked. I just passed 10M iterations, which it
was unable to do previously. I am now doing 100M just to be an idiot :)

Nice catch~
Nic
-- 
Nicholas Henke
Penguin Herder & Linux Cluster System Programmer
Liniac Project - Univ. of Pennsylvania