deadlock caused by idprio?

Doug Lee dgl at
Sat Nov 19 18:32:43 GMT 2005

I just ran a MySQL lookup process (written in Perl) as root prefixed
with "idprio 1."  I expected it to take a while, but not several
minutes.  After a while I decided to abort it, so I typed ^c in its
`screen' window.  From then on (either from the ^c point or the idprio
run, I know not which), I could not create any new processes, nor
could I kill the running task.  Any attempt to do either would hang
indefinitely.  I could end processes and work within existing
processes as long as they didn't try to create new ones.  I entered
the debugger (I use the alt method of <cr>~^b) and typed, among other
things, "show lockedvnodes" and got one vnode which said "... with 22
pending," and this count went up by 1 each time I tried creating a new
process.  Sadly, I forgot to snapshot that screen, so I can't quote
the rest of that entry.  I remember it said VDIR and type
something+VOBJECT, but I don't remember what the something was.
Unable to retrieve my system, I finally typed "panic" in the debugger
so at least the disks would sync.  Other than "giving up on 4
buffers," that went fine.

Any ideas what this is, and whether it's a bug?  I thought idprio was
harmless as far as affecting other processes.

uname -a:
FreeBSD 4.10-STABLE FreeBSD 4.10-STABLE #0: Sun Aug  8 03:03:49 EDT 2004     dgl at  i386

Doug Lee                 dgl at        
SSB + BART Group         doug at
"Is your cucumber bitter? Throw it away. Are there briars in your
path? Turn aside. That is enough. Do not go on to say, `Why were
things of this sort ever brought into the world?'"
--Marcus Aurelius

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