Re: sparc32 SMP debugging advice needed

["BERTRAND Joël" <joel.bertrand@systella.fr>]

	Hello,

Robert Reif a écrit :
> I'm trying to get a git rc4 SMP kernel working on an ss20 and am running
> into a few problems.

	I have built the same kernel with some debug information about 
deadlocks and spinlocks. This kernel works fine with one SuperSPARC but 
not with one HyperSPARC (cache aliasing management mistake). With dual 
SuperSPARC (SM71), kernel randomly hangs with spinlock bug. Sometimes, 
it can boot, sometimes not, and I don't know how debug this kernel. When 
it completely boots, I can see some deadlocks (for example, run "make 
-j2" to build a kernel randomly stops with cc in D state), some randomly 
oops (syscall_to_hard) when pipe syscall is executed.

> An SMP kernel boots and runs fine using debian etch and a single
> CPU.  However I do get this in kern.log:
> 
> Mar 23 10:59:53 ss20 kernel: Kernel command line: root=/dev/sda2 ro
> Mar 23 10:59:53 ss20 kernel: PID hash table entries: 1024 (order: 10, 
> 4096 bytes)
> Mar 23 10:59:53 ss20 kernel: start_kernel(): bug: interrupts were 
> enabled early
> Mar 23 10:59:53 ss20 kernel: Console: colour dummy device 80x25
> 
> It looks like something similar was fixed a while back on sparc64 but
> I don't know if this is related.  I'm recompiling a kernel with more
> debugging turned on to see what happens.
> 
> I get a hang when booting the same kernel with 2 CPUs at:
> 
> Begin: Loading essential drivers... ...
> 
> Nothing interesting before that.
> 
> Any advice on how to approach fixing these issues?  I can test patches.

	I can test too. If someones has some idea about this trouble or a 
method to debug this kernel, he is welcome ;-)

	Regards,

	JKB