On Fri, 2006-11-17 at 15:17 +0100, M. Koehrer wrote:
> Hi Jan,
>
> First, I give you some more information about the error.
> The output is the following:
> Hi, I am task A Hello
> Hi, I am task B World
> Main waits for A
> This is the end of A
> Main waits for B
>
> Then the system hangs.
>
Confirmed here on a two-way PIII. Well, _this_ was a nice one.
Basically, the softlock was due to a missing rescheduling call after
task A has exited, leaving task B in ready state, somewhere in the
Twilight Zone. The patch below fixes it on my setup:
--- ksrc/nucleus/shadow.c (revision 1854)
+++ ksrc/nucleus/shadow.c (working copy)
@@ -1631,7 +1631,8 @@
static inline void do_taskexit_event(struct task_struct *p)
{
- xnthread_t *thread = xnshadow_thread(p); /* p == current */
+ xnthread_t *thread = xnshadow_thread(p); /* p == current */
+ spl_t s;
if (!thread)
return;
@@ -1639,12 +1640,15 @@
if (xnpod_shadow_p())
xnshadow_relax(0);
- /* So that we won't attempt to further wakeup the exiting task in
- xnshadow_unmap(). */
-
+ xnlock_get_irqsave(&nklock, s);
+ /* Prevent wakeup call from xnshadow_unmap(). */
xnshadow_thrptd(p) = NULL;
xnthread_archtcb(thread)->user_task = NULL;
- xnpod_delete_thread(thread); /* Should indirectly call
xnshadow_unmap(). */
+ /* xnpod_delete_thread() -> hook -> xnshadow_unmap(). */
+ xnpod_delete_thread(thread);
+ xnsched_set_resched(thread->sched);
+ xnpod_schedule();
+ xnlock_put_irqrestore(&nklock, s);
xnltt_log_event(xeno_ev_shadowexit, thread->name);
}
--
Philippe.
_______________________________________________
Xenomai-help mailing list
[email protected]
https://mail.gna.org/listinfo/xenomai-help
