this is 1.6ZG (sources from just a day ago or so) w/ MPBIOS, MPACPI and
ACPI_PCI_FIXUP.  I'm not sure what to make of this panic; x86_send_ipi
takes only 2 arguments but 5 are listed.  what are the others? any clues?

login: kernel: double fault trap, code=0
Stopped in pid 3767.1 (vsftpd) at       netbsd:Xintr_lapic_ipi+0x7:     mov     
%gs,0(%esp)
db{6}> 
db{6}> trace
Xintr_lapic_ipi() at netbsd:Xintr_lapic_ipi+0x7
--- interrupt ---
Bad frame pointer: 0xf0997000
0:
db{6}> machine cpu
addr            dev     id      flags   ipis    curproc         fpcurproc
0xc0402bc0      cpu0    0       7009    0       0xe7bda5d8      0xe7bdadd0
0xc44b8000      cpu1    6       b002    10      0xe92265dc             0x0
db{6}> trace
x86_send_ipi(c44b8000,10,0,0,c0e67c78) at netbsd:x86_send_ipi+0x16
pmap_clear_attrs(c0e67c40,40,11870000,93be000,c0e6a780) at netbsd:pmap_clear_attrs+0x1ae
genfs_putpages(e7c0bd04,c196cc80,0,e7c0bc54,e7c0bc94) at netbsd:genfs_putpages+0xbf1
ffs_full_fsync(e7c0be94,ceb639f4,e7c0bdec,c01e8395,e7c0bd74) at netbsd:ffs_full_fsync+0x360
ffs_fsync(e7c0be94,10012,400000,0,40100) at netbsd:ffs_fsync+0x52
ffs_sync(c4909600,3,c449be80,e7c0333c,c036aa60) at netbsd:ffs_sync+0x2b3
sync_fsync(e7c0bf44,12,2,0,0) at netbsd:sync_fsync+0xba
sched_sync(e7bda5d8,4a8000,4b1000,0,c010030c) at netbsd:sched_sync+0x218


full dmesg at http://www.shrubbery.net/~heas/dmesg