Re: [Xenomai-core] trunk: xnsched_set_policy seems to set only cprio

[Philippe Gerum <rpm@xenomai.org>]

Jan Kiszka wrote:
> Hi,
> 
> unfortunately I'm forced to switch to other bugs, but I found out a bit
> more about the issue that pthread_getschedparam doesn't return the
> correct policy&prio under trunk - at least when called from threads
> created via pthread_create as SCHED_FIFO:
> 
> Such threads start with SCHED_OTHER, but then the propagation via
> do_setsched_event and finally xnsched_set_policy only seems to affect
> thread.cprio, not bprio. Will see if I can continue debugging this
> later, but maybe /someone/ already knows what goes wrong...
> 

With the new scheduler infrastructure, ->bprio tends to be used solely as a
priority backup area when dealing with PIP; but at the same time, some skins
still consider it as an always up-to-date location where to find the nominal
priority of a thread, so this hunk should help in keeping things compatible with
2.4.x:

diff --git a/ksrc/nucleus/sched.c b/ksrc/nucleus/sched.c
index 8d50a6b..3b95fbb 100644
--- a/ksrc/nucleus/sched.c
+++ b/ksrc/nucleus/sched.c
@@ -395,6 +395,7 @@ int xnsched_set_policy(struct xnthread *thread,
 	thread->sched_class = sched_class;
 	thread->base_class = sched_class;
 	xnsched_setparam(thread, p);
+	thread->bprio = thread->cprio;

 	if (xnthread_test_state(thread, XNREADY))
 		xnsched_enqueue(thread);

> Thanks,
> Jan
> 


-- 
Philippe.