Strange deadlock

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

        Hello,

	Some weeks ago, I have indicated here I have a stability issue with my 
Blade2000 running NetBSD :

trap type 0x68: cpu 1, pc=410657c0 npc=410657ac 
pstate=0xffffffff99820092<,PEF,IE>
Skipping crash dump on recursive panic
panic: +fast data access MMU miss
cpu1: Begin traceback...
cpu1: End traceback...
cpu0: shutting down
cpu1: rebooting

	That was with 6.99.40 kernel. I have changed a faulty memory module, 
rebuilt all packages I use from sources (perl, gtk and all dependencies) 
and rebuilt a new kernel :

NetBSD legendre.systella.fr 6.99.47 NetBSD 6.99.47 (CUSTOM) #1: Sun Jul 
20 15:21:37 CEST 2014 
root%legendre.systella.fr@localhost:/usr/src/sys/arch/sparc64/compile/CUSTOM sparc64

        CUSTOM stands for GENERIC.MP with some minor modifications :

sd0     at scsibus4 target 0 lun 0
sd1     at scsibus4 target 1 lun 0
cd0     at scsibus0 target 6 lun 0
...
# Wedge support
options         DKWEDGE_AUTODISCOVER
options         DKWEDGE_METHOD_GPT

	With 6.99.40 kernel, this workstation was stable enough to build 
packages from sources (load average : 6). With 6.99.47, it has hanged 
just after a few hours.

	At 12:48 (CEST), this workstation has crashed under heavy I/O (gcc48 
compilation). Something very similar to a deadlock and I have rebooted 
it with power button. Console didn't respond, network subsystem didn't 
answer to ping... There was no information on console or serial line. No 
panic and no dump file.

	I don't think if it is sparc specific, I don't have any other 
information. Has anyone ever seen the same problem?

        Best regards,

        JB