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.
>> 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.
Steven
Index: linux-2.6.19/arch/arm/lib/backtrace.S
===================================================================
--- linux-2.6.19.orig/arch/arm/lib/backtrace.S
+++ linux-2.6.19/arch/arm/lib/backtrace.S
@@ -100,7 +100,7 @@ ENTRY(c_backtrace)
*/
1007: ldr r0, =.Lbad
mov r1, frame
- bl printk
+ bl my_printk
ldmfd sp!, {r4 - r8, pc}
.ltorg
@@ -134,12 +134,12 @@ ENTRY(c_backtrace)
ldr r2, [stack], #-4
mov r1, reg
adr r0, .Lfp
- bl printk
+ bl my_printk
2: subs reg, reg, #1
bpl 1b
teq r7, #0
adrne r0, .Lcr
- blne printk
+ blne my_printk
mov r0, stack
ldmfd sp!, {instr, reg, stack, r7, r8, pc}
Index: linux-2.6.19/include/linux/kernel.h
===================================================================
--- linux-2.6.19.orig/include/linux/kernel.h
+++ linux-2.6.19/include/linux/kernel.h
@@ -146,6 +146,12 @@ asmlinkage int vprintk(const char *fmt,
__attribute__ ((format (printf, 1, 0)));
asmlinkage int printk(const char * fmt, ...)
__attribute__ ((format (printf, 1, 2)));
+
+
+asmlinkage int my_printk(const char * fmt, ...)
+ __attribute__ ((format (printf, 1, 2)));
+
+
#else
static inline int vprintk(const char *s, va_list args)
__attribute__ ((format (printf, 1, 0)));
Index: linux-2.6.19/kernel/printk.c
===================================================================
--- linux-2.6.19.orig/kernel/printk.c
+++ linux-2.6.19/kernel/printk.c
@@ -524,6 +524,21 @@ void __ipipe_flush_printk (unsigned virq
spin_unlock_irqrestore(&__ipipe_printk_lock, flags);
}
+/*FIXME*/
+extern void printascii(const char *);
+asmlinkage int my_printk(const char *fmt, ...)
+{
+ va_list va;
+ char buff[256];
+
+ va_start(va, fmt);
+ vsprintf(buff, fmt, va);
+ va_end(va);
+
+ printascii(buff);
+ return 0;
+}
+
asmlinkage int printk(const char *fmt, ...)
{
int r, fbytes, oldcount;
Index: linux-2.6.19/kernel/sched.c
===================================================================
--- linux-2.6.19.orig/kernel/sched.c
+++ linux-2.6.19/kernel/sched.c
@@ -3327,8 +3327,14 @@ asmlinkage void __sched schedule(void)
struct rq *rq;
#ifdef CONFIG_IPIPE
- if (unlikely(!ipipe_root_domain_p))
+ if (unlikely(!ipipe_root_domain_p)) {
+ my_printk("ipipe_current_domain != ipipe_root_domain !\n");
+ my_printk("ipipe_current_domain = %p\n", ipipe_current_domain);
+ my_printk("ipipe_root_domain = %p\n", ipipe_root_domain);
+ __backtrace();
+ while (1) { barrier();};
return;
+ }
#endif /* CONFIG_IPIPE */
/*
* Test if we are atomic. Since do_exit() needs to call into
_______________________________________________
Xenomai-core mailing list
Xenomai-core@gna.org
https://mail.gna.org/listinfo/xenomai-core
