Steven Scholz wrote: > Gilles, > > >>>I am running 2.6.19 + adeos-ipipe-2.6.19-arm-1.6-02.patch + >>>xenomai-svn-2007-02-22 >>>on an AT91RM9200 (160MHz/80MHz). >>> >>>When starting "latency -p 200" it runs for a while printing >>> >>>RTT| 00:05:37 (periodic user-mode task, 200 us period, priority 99) >>>RTH|-----lat min|-----lat avg|-----lat max|-overrun|----lat best|---lat worst >>>RTD| 11.200| 139.200| 236.800| 1| 10.800| 280.800 >>> >>>but then hangs. The timer LED stops blinking. No "soft lockup detected" >>>appears. >> >>The only explanation I have is that the period is too small. I do not >>observe the same behaviour with latency -p 1000. Note that setting the >>period to a value comparable to the latency is not considered a normal >>use of Xenomai. > > > Sure but I would still not expect the system to hang! > As I said missing a deadline is bad but ok. > But hanging the whole system is not quite ok.
I want this bug solved too, especially since I am not sure that we will only see it with too short periods. > > >>>Using a BDI200 it looks like that in kernel/sched.c:schedule() he is >>>returning >>>in the lines >>> >>>#ifdef CONFIG_IPIPE >>> if (unlikely(!ipipe_root_domain_p)) >>> return; >>>#endif /* CONFIG_IPIPE */ >>> >>>When stepping trough I only see him getting into schedule() but leaving >>>it in the above lines and in include/linux/proc_fs.h:proc_net_fops_create() >>>... >> >>Ok. Thanks for pointing this out. That is interesting, but not very >>informative. It would be interesting if you could get the full >>backtrace. What would be also interesting would be to set a break point >>on the timer interrupt handler and to follow what happens from timer >>interrupt to timer interrupt. > > > I tried! Attached the patch I used. Since teh scheduler hangs I can't use > normal printk(), right? > > *ipipe_current_domain != ipipe_root_domain ! > *ipipe_current_domain = c01fc2c0 > *ipipe_root_domain = c01af2c0 > > But I don't get the output of __backtrace()! > > my_printk() works with __backtrace(). The dump of a soft lockup works. I would add the call to printascii(printk_buff) directly in vprintk, and use printk. Note however that special care must be taken to avoid recursion when calling printk inside schedule, because printk may use schedule. Anyway, I think the tracer will give better results than a simple backtrace. -- Gilles Chanteperdrix _______________________________________________ Xenomai-core mailing list Xenomaifirstname.lastname@example.org https://mail.gna.org/listinfo/xenomai-core