Re: vn_fullpath: 0xc85e24a0 is not locked but should be

At Fri, 12 Dec 2003 19:37:24 -0500 (EST),
Robert Watson wrote:
> BTW, if someone wants to actually test the patch I posted, I'll be happy
> to commit it :-).  I'll modify it to include a comment about lock orders,
> however -- I think procfs will always be something of a lock ordering
> challenge, however.  My understanding is that procfs doesn't rely on vnode
> locks for internal consistency, so we may well just be able to drop and
> reclaim the vnode lock for this (and also for the map file). 

I get a hang of my Mozilla with situation below.  I'm running this box
with your patch and I'm not sure this will happen without your patch.

I'm doing "make install" at /usr/ports/print/cups-base in another
window, and it looks cvsup process is running as cron job.

Is there any thing I can provide for debugging?


----- ps output
USER       PID %CPU %MEM   VSZ  RSS  TT  STAT STARTED      TIME COMMAND
root        54  0.0  0.0     0   12  ??  DL   Wed10AM   1:44.12  (bufdaemon)
root        56  0.0  0.0     0   12  ??  DL   Wed10AM  15:55.36  (syncer)
kuriyama 30217  0.0  2.9 75672 61208  v0  D    Wed11AM   7:18.35 ./mozilla-bin
root     59334  0.0  0.0  1348  992  pb  D+    2:58PM   0:00.03 /usr/bin/install -c -o root -g wheel -m 644 printers.tmpl
kuriyama 59698  0.0  0.2  3752 3352  ??  D     3:06PM   0:00.62 /usr/local/bin/cvsup -g -L0 -l /home/kuriyama/
-----

----- top output
  PID USERNAME PRI NICE   SIZE    RES STATE  C   TIME   WCPU    CPU COMMAND
30217 kuriyama  -4    0 75672K 61208K snaplk 1   7:18  0.00%  0.00% mozilla-bin
-----

----- ddb show lockedvnods
db> show locekedvnods
Locked vnodes
0xc9aa1940: tag ufs, type VREG, usecount 3, writecount 2, refcount 1, flags (VV_OBJBUF), lock type ufs: EXCL (count 1) by thread 0xc94b7dc0 (pid:30217)
        ino 1109137, on dev ad0s1f (4, 17)
0xc86e9250: tag ufs, type VREG, usecount 1, writecount 0, refcount 103, flags (VV_SYSTEM), lock type snaplk: EXCL (count 1) by thread 0xc8228140 (pid:56) with 4 pending
        ino 965633, on dev ad0s1f (4, 17)
0xc86e9128: tag ufs, type VREG, usecount 1, writecount 0, refcount 103, flags (VV_SYSTEM), lock type snaplk: EXCL (count 1) by thread 0xc8228140 (pid:56) with 4 pending
        ino 965634, on dev ad0s1f (4, 17)
0xc86e7a68: tag syncer, type VNON, usecount 1, writecount 0, refcount 1, lock type syncer: EXCL (count 1) by thread 0xc8228140 (pid:56)
0xc94c76f0: tag ufs, type VREG, usecount 1, writecount 0, refcount 134, flags (VV_SYSTEM|VV_OBJBUF), lock type snaplk: EXCL (count 1) by thread 0xc8228140 (pid:56) with 4 pending
        ino 965635, on dev ad0s1f (4, 17)
0xc936ecb8: tag ufs, type VREG, usecount 1, writecount 0, refcount 1, flags (VV_OBJBUF), lock type ufs: EXCL (count 1) by thread 0xc8228140 (pid:56)
        ino 1366863, on dev ad0s1f (4, 17)
0xcf7b2a68: tag ufs, type VREG, usecount 0, writecount 0, refcount 1, flags (VV_OBJBUF), lock type ufs: EXCL (count 1) by thread 0xc81ecdc0 (pid:54)
        ino 1367549, on dev ad0s1f (4, 17)
0xcf6bacb8: tag ufs, type VDIR, usecount 1, writecount 0, refcount 1, lock type ufs: EXCL (count 1) by thread 0xc9be4a00 (pid:59334)
        ino 1791839, on dev ad0s1f (4, 17)
0xca54bde0: tag ufs, type VREG, usecount 2, writecount 1, refcount 1, flags (VV_OBJBUF), lock type ufs: EXCL (count 1) by thread 0xc9be4000 (pid:59698)
        ino 1114492, on dev ad0s1f (4, 17)
-----


-- 
Jun Kuriyama <kuriyama_at_imgsrc.co.jp> // IMG SRC, Inc.
             <kuriyama_at_FreeBSD.org> // FreeBSD Project