today I updated my source tree for the first time since January,
and now I'm very repeatably getting "crazy interrupts" panics.
this sample output is from a "tar xv" interspersed with some
debugging kernel printfs, using a serial console on a sparc1:


ubc_fault: setting pg 0xf01e4d00 vp 0xf02f9400 offset 0x111c000 valid 0x3
tv/pink_panther.au
ubc_fault: setting pg 0xf01e8540 vp 0xf02f9400 offset 0x12ae000 valid 0x3
HI! spec_strategy: rw 0 vp 0xf02f9400 blkno 0xa0 bcount 0x400
spec_putpages: bcount lowered from 0x1000 to 0x400
HI! spec_strategy: rw 0 vp 0xf02f9400 blkno 0x30 bcount 0x400
spec_putpages: bcount lowered from 0x1000 to 0x400
HI! spec_strategy: rw 0 vp 0xf02f9400 blkno 0xcc0 bcount 0x400
spec_putpages: bcount lowered from 0x1000 to 0x400
python/ubstray interrupt ipl 0xc pc=0xf00fad18 npc=0xf00fad1c psr=5c5<S,PS>
cstray interrupt ipl 0xc pc=0xf00fad18 npc=0xf00fad1c psr=5c5<S,PS>
_stray interrupt ipl 0xc pc=0xf00fad18 npc=0xf00fad1c psr=5c5<S,PS>
fstray interrupt ipl 0xc pc=0xf00fad18 npc=0xf00fad1c psr=5c5<S,PS>
austray interrupt ipl 0xc pc=0xf00fad18 npc=0xf00fad1c psr=5c5<S,PS>
lstray interrupt ipl 0xc pc=0xf00fad18 npc=0xf00fad1c psr=5c5<S,PS>
tstray interrupt ipl 0xc pc=0xf00fad18 npc=0xf00fad1c psr=5c5<S,PS>
:stray interrupt ipl 0xc pc=0xf00fad18 npc=0xf00fad1c psr=5c5<S,PS>
 stray interrupt ipl 0xc pc=0xf00fad18 npc=0xf00fad1c psr=5c5<S,PS>
sstray interrupt ipl 0xc pc=0xf00fad18 npc=0xf00fad1c psr=5c5<S,PS>
panic: crazy interrupts
Stopped at      _Debugger+0x4:  jmpl            [%o7 + 0x8], %g0
db> 


it kinda looks like the lossage happens when a kernel printf occurs
while there's normal user console output going on already.  I tried
undoing mycroft's cs_heldchar changes of March 29 since they looked
relevant, and the problem went away for me.  is anyone else seeing
anything like this?

(and I must say, the cs_heldchar thingy can be really annoying itself...
a while back I had a bug that would often land me in ddb with a held char,
which meant that what appeared on the screen was a character behind
what I was typing...)

-Chuck