debugging a pool_get panic

[Tim Rightnour <root%garbled.net@localhost>]

I got the following panic on my ofppc SMP machine while doing some rather light
benchmarking on it, and am unsure how to proceed.  Any help debugging this
would be appreciated.

panic: pool_get: pmap_mpvopl: page empty
db{0}> bt
0xaaf7bc90: at panic+0x228
0xaaf7bce0: at pool_get+0x380
0xaaf7bd00: at pmap_pvo_enter+0x3d28
0xaaf7bd50: at pmap64bridge_enter+0x140
0xaaf7bd80: at uvm_fault_internal+0xc6c
0xaaf7beb0: at trap+0x1d0
0xaaf7bf40: user ISI trap by 0xeff0f0d4: srr1=0x4000d032
            r1=0xffffd780 cr=0x24002022 xer=0 ctr=0xeff0f0d4

POOL pmap_mpvopl: size 64, align 64, ioff 0, roflags 0x00000040
        alloc 0x4e5594
        minitems 1008, minpages 16, maxpages 4294967295, npages 139
        itemsperpage 63, nitems 1065, nout 7692, hardlimit 4294967295
        nget 9649738, nfail 0, nput 9642046
        npagealloc 139, npagefree 0, hiwat 139, nidle 16
                
        empty page list:
                page 0xe000, nmissing 0, time 1846  
                page 0x0, nmissing 6, time 4294967295
                page 0x0, nmissing 0, time 0

        full page list:
                page 0x19000, nmissing 63, time 1846
                page 0x52000, nmissing 63, time 1805
        [lots more like this, all with nmissing == 63]
                page 0xdb000, nmissing 63, time 1
                page 0xff000, nmissing 63, time 1
                
        partial-page list:
                page 0x0, nmissing 6, time 4294967295
                page 0x0, nmissing 0, time 0
        curpage 0x0

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Tim Rightnour <root%garbled.net@localhost>
NetBSD: Free multi-architecture OS http://www.netbsd.org/
Genecys: Open Source 3D MMORPG: http://www.genecys.org/