panic: mutex vm object not owned ...

[Garance A Drosihn]

Well, I thought I should update to the latest snapshot of -current,
to see if that would help with some other testing I'm doing.  I
booted up off the new kernel okay (in single-user mode), and then
started a 'make installworld'.  After a few minutes of install-
worlding, the system paniced with:

panic: mutex vm object not owned at /usr/src/sys/vm/vm_page.c:608
KDB: enter: panic
[thread pid 7 tid 100026 ]
Stopped at      0x244ee8:    lwz  R11,1,0x0
db>

I tried "call doadump", but no dump device is defined so it
couldn't do anything.

I tried "call cpu_reset()", and it came up with:

fatal kernel trap:
    exception       = 0xaab9cb (unknown)
    srr0            = 0xbabbbcba
    srr1            = 0xbbbdbecd
    curthread       = 0xf634960
           pid = 7, comm = pagedaemon

panic: unknown trap
Uptime 4m15s

I rebooted, did an "fsck -y", tried another installworld, and I
got the same panic.  This time I did a 'trace', and got:

Tracing pid 7 tid 100026 td 0xf634960
0xd7cc1ac8: at panic+0x134
0xd7cc1b68: at _mtx_assert+0x74
0xd7cc1b88: at vm_page_remove+0x5c
0xd7cc1ba8: at vm_page_free_toq+0xcc
0xd7cc1bc8: at vm_page_free+0x28
0xd7cc1be8: at uma_small_free+0x60
0xd7cc1c18: at zone_drain+0x2e8
0xd7cc1c58: at zone_foreach+0x64
0xd7cc1c78: at uma_reclaim+0x20
0xd7cc1c98: at vm_pageout_scan+0x200
0xd7cc1d58: at vm_pageout+0x39c
0xd7cc1d98: at fork_exit+0x118
0xd7cc1dc8: at fork_trampoline+0xc

Disclaimer: All of the above is typed in by hand...

I then tried "call cpu_reset()", and it again paniced with the
fatal kernel trap.  I thought cpu_reset() was supposed to be just
like hitting a hardware-reboot button...

This had been running a snapshot of world from Feb 8th.  This is
the only machine I tried to upgrade last night, so I don't know if
this is a PPC-specific bug, or a general bug.

Now to see if I can figure out how to get back to a working system...

-- 
Garance Alistair Drosehn            =   gad at gilead.netel.rpi.edu
Senior Systems Programmer           or  gad at freebsd.org
Rensselaer Polytechnic Institute    or  drosih at rpi.edu