RELENG_6 Livelock

[John Baldwin]

On Sunday 17 September 2006 02:05, Frode Nordahl wrote:
> On 17. sep. 2006, at 04.42, John Baldwin wrote:
> 
> > On Saturday 16 September 2006 16:55, Frode Nordahl wrote:
> >> On 16. sep. 2006, at 22.22, Frode Nordahl wrote:
> >>
> >>> On 16. sep. 2006, at 22.09, John Baldwin wrote:
> >>>
> >>>> On Saturday 16 September 2006 07:02, Frode Nordahl wrote:
> >>>>> Hello,
> >>>>>
> >>>>> FreeBSD localhost.localdomain 6.2-PRERELEASE FreeBSD 6.2- 
> >>>>> PRERELEASE
> >>>>> #1: Wed Sep 13 00:10:04 CEST 2006      
> >>>>> frode at localhost.localdomain:/
> >>>>> usr/obj/usr/src/sys/PT  i386
> >>>>>
> >>>>> After running some stress tests for 3 days, I wanted to remove  
> >>>>> some
> >>>>> large directories.
> >>>>
> >>>> Do you have a coredump?  I assume you do from your debug  
> >>>> output.  Can
> >>>> you download http://www.FreeBSD.org/~jhb/gdb/gdb6, fire up kgdb,  
> >>>> and
> >>>> once in kgdb, do 'source /path/to/gdb6' and then run 'ps' and reply
> >>>> with the output from that?
> >>>
> >>> I am sorry, I have not. I tried to call doadump, but there was no
> >>> dumpdevice configured :-(
> >>>
> >>> Somehow I have convinced myself that this was turned on by default
> >>> now, so I have not enabled it explicitly in rc.conf. Is there any
> >>> way to tell DDB what dumpdevice to use directly?
> >>>
> >>> I will configure a dumpdevice and try really hard to make it happen
> >>> again.
> >>
> >> I was able to reproduce the livelock again, and this time I had the
> >> system armed with dumpon :-)
> >>
> >> Here is the output you requested:
> >> (kgdb) ps
> >>    pid  ppid  pgrp   uid   state   wmesg     wchan    cmd
> >> 2535  2499  2535     0  R+      CPU  0              rm
> >> 2534  2499  2534     0  L+     *Giant    0xc6704580 rm
> >> 2533  2499  2533     0  L+     *Giant    0xc6704580 rm
> >> 2532  2499  2532     0  R+                          rm
> >> 2531  2499  2531     0  L+     *Giant    0xc6704580 rm
> >> 2499  2496  2499     0  Ss+     ttyin    0xc655d810 bash
> >> 2496   784  2496     0  Rs                          sshd
> >
> > Ok, do 'lockchain 2534' in kgdb (with gdb6 sourced) and let me see the
> > output from that.
> 
> (kgdb) lockchain 2534
> thread 100038 (pid 2534, rm) blocked on lock 0xc09e6800 "Giant"
> thread 100091 (pid 2535, rm) running on CPU 0

Ok, do 'proc 2535' followed by 'where'

-- 
John Baldwin