US-III crashes on current

[Marius Strobl]

On Tue, Apr 21, 2009 at 09:15:32PM +0200, Florian Smeets wrote:
> On 21.04.09 20:58, Marius Strobl wrote:
> >On Tue, Apr 21, 2009 at 01:45:27AM +0200, Florian Smeets wrote:
> >>
> >>Yes, i can still reproduce this on every shutdown. Tried with r191337.
> >>Trace is still the same.
> >>
> >
> >Could you please run gdb(1) on the corresponding kernel.debug
> >and report the output of the following commands?
> >l *(0xc034c96c)
> >l *(callout_lock+0x40)
> >Change as needed if the addresses differ from the above
> >backtrace. Hrm, the one you reported to scsi@ actually
> >is a bit different:
> >>-- fast data access mmu miss tar=0x1454156000 %o7=0xc040e7a4 --
> >>_mtx_lock_spin_flags() at _mtx_lock_spin_flags+0x5c
> >>callout_lock() at callout_lock+0x50
> >
> >In that case please additionally get the output of
> >l *(_mtx_lock_spin_flags+0x5c)
> >
> 
> OK, to get this straight this is the trace I'm talking about.
> 
> Uptime: 19h19m49s
> panic: trap: fast data access mmu miss
> cpuid = 0
> KDB: enter: panic
> [thread pid 97473 tid 100179 ]
> Stopped at      kdb_enter+0x80: ta              %xcc, 1
> db> where
> Tracing pid 97473 tid 100179 td 0xfffff80006dfc370
> panic() at panic+0x20c
> trap() at trap+0x4d0
> -- fast data access mmu miss tar=0x20007e000 %o7=0xc03f70a4 --
> callout_lock() at callout_lock+0x20
> untimeout() at untimeout+0xc
> isp_done() at isp_done+0x140
> isp_intr() at isp_intr+0x3eb8
> isp_poll() at isp_poll+0x38
> xpt_polled_action() at xpt_polled_action+0xc8
> dashutdown() at dashutdown+0x16c
> boot() at boot+0x850
> reboot() at reboot+0x64
> syscall() at syscall+0x2b4
> -- syscall (55, FreeBSD ELF64, reboot) %o7=0x1013e4 --
> userland() at 0x40564948
> user trace: trap %o7=0x1013e4
> pc 0x40564948, sp 0x7fdffffe201
> pc 0x100df0, sp 0x7fdffffe2c1
> pc 0x40206954, sp 0x7fdffffe381
> done
> 
> (gdb) l *(0xc03f70a4)
> 0xc03f70a4 is in spinlock_exit (/usr/src/sys/sparc64/sparc64/machdep.c:232).
> 227	spinlock_exit(void)
> 228	{
> 229		struct thread *td;
> 230	
> 231		td = curthread;
> 232		critical_exit();
> 233		td->td_md.md_spinlock_count--;
> 234		if (td->td_md.md_spinlock_count == 0)
> 235			wrpr(pil, td->td_md.md_saved_pil, 0);
> 236	}

Hrm, this suggests that curthread or the per-CPU data went
missing at that point, which leaves me clueless at the
moment. Do you see this problem since installing FreeBSD
on that machine or has it developed later? If the latter,
can you pinpoint when it started? What kind of access for
debugging could you provide?

Marius