"busy buffer problem" panics

[Andrew Atrens <atrens@xxxxxxxxxxxxxxxxxx>]

Hi Folks,

For the last two days with an up-to-date kernel I've been
getting regular panics. Cadence is roughly once every 24
hours, although I just got one after only ~7 hours of uptime
right after starting a 'nice make -j99 buildworld' and
then running a clearcase/linux command.

Most of the core/tracebacks look similar to this one,
but happen in the middle of the night so I'm not around to
capture them.

This one happened more or less instantly upon running the 
clearcase/linux command while the buildworld was running.

Not sure what's running when the late night panics happen,
most likely just a screensaver and some cron filesystem
sweepers.

Btw, as an aside I'm finding that when I run 'nice' builds
they almost invariably die with some sort of internal
compiler error. When running the same build without 'nice'
it invariably works without error. This behaviour is kind of
random in that it's always a different file that fails, but
predictable in that buildworld 'always' fails at some point.

Andrew.

Today's panic -

Debugger("busy buffer problem")
Stopped at      Debugger+0x3e:  movb    $0,in_Debugger.0
db> trace
Debugger(c0417f7f,8,8,8,14) at Debugger+0x3e
boot(100,c04af2e0,c04379b8,d9c227f4,1010002) at boot+0x265
poweroff_wait(c04379b8,d73d2b18,d7a02680,d5fa1340,d73d2b18) at poweroff_wait
lockmgr(d73d2b18,1010002,d9c228ac,d5fa1340,d9c22850) at lockmgr+0x339
vop_stdlock(d9c2285c,d9c22890,c0228634,d9c2285c,c0470b60) at
vop_stdlock+0x2c
vop_defaultop(d9c2285c,c0470b60,d2a0bc00,d9dc55a0,d78c09a0,11bb,d9c228a4,d73d2aa0,d9c228ac,1010002,d5fa1340,d9c22b14,2)
at vop_defau
ltop+0x18
vop_lock(d2a0bc00,d73d2aa0,d9c228ac,1010002,d5fa1340) at vop_lock+0x6b
vn_lock(d73d2aa0,0,2,d5fa1340,c04b0bf8) at vn_lock+0xa3
vrele(d73d2aa0,d73d2aa0,0,d9c22b14,0) at vrele+0x84
lookup(d9c22b00,d305f800,6,c2765fa8,0) at lookup+0x58e
namei(d9c22b00,d2aee80d,3f3,d9c229dc,d5fa1340) at namei+0x232
linux_copyin_path(bfbfbb78,d9c22b84,2,d9c22bc4,d2aee800) at
linux_copyin_path+0x171
linux_readlink(d9c22c24,d9c22d0c,d9c22c1c,d9c22c20,3) at linux_readlink+0x38
syscall2(2f,2f,2f,bfbfbb87,bfbfbab7) at syscall2+0x25f
Xint0x80_syscall() at Xint0x80_syscall+0x2a
db> c
Uptime: 6h50m22s
twe0: failed to delete unit 0


from early this morning -

(kgdb) bt
#0  0xc01df7df in dumpsys ()
#1  0xc01df57a in boot ()
#2  0xc01dfa55 in poweroff_wait ()
#3  0xc01d6f0f in lockmgr ()
#4  0xc021ab3c in vop_stdlock ()
#5  0xc021a9ea in vop_defaultop ()
#6  0xc0228634 in vop_lock ()
#7  0xc0227807 in vn_lock ()
#8  0xc021e3e5 in vrele ()
#9  0xc021bd81 in lookup ()
#10 0xc021b532 in namei ()
#11 0xc06184d1 in ?? ()
#12 0xc060e6cc in ?? ()
#13 0xc03cf847 in syscall2 ()
#14 0xc03bf80a in Xint0x80_syscall ()
#15 0x28611a73 in ?? ()
#16 0x284a32e1 in ?? ()
#17 0x28492c85 in ?? ()
#18 0x28492f02 in ?? ()
#19 0x8049f92 in ?? ()
#20 0x2858054d in ?? ()
(kgdb)


And another from yesterday -

(kgdb) bt
#0  0xc01df7df in dumpsys ()
#1  0xc01df57a in boot ()
#2  0xc01dfa55 in poweroff_wait ()
#3  0xc01d6f0f in lockmgr ()
#4  0xc021ab3c in vop_stdlock ()
#5  0xc021a9ea in vop_defaultop ()
#6  0xc0228634 in vop_lock ()
#7  0xc0227807 in vn_lock ()
#8  0xc021e3e5 in vrele ()
#9  0xc021bd81 in lookup ()
#10 0xc021b532 in namei ()
#11 0xc06184d1 in ?? ()
#12 0xc060e6cc in ?? ()
#13 0xc03cf847 in syscall2 ()
#14 0xc03bf80a in Xint0x80_syscall ()
#15 0x28611a73 in ?? ()
#16 0x284a32e1 in ?? ()
#17 0x28492c85 in ?? ()
#18 0x28492f02 in ?? ()
#19 0x8049f92 in ?? ()
#20 0x2858054d in ?? ()
(kgdb)