[PATCH] Lockmgr deadlock on STABLE_8

[Attilio Rao]

2010/1/14 Pete French <petefrench at ticketswitch.com>:
>> http://www.freebsd.org/~attilio/lockmgr_fix8.diff
>>
>> I'm seeking for testers here.
>> Any report would be very much appreciated.
>
> I tested the patch on my machine which locks up, and I am afraid that it
> still locks, even with the patch applied. The last things on the console
> before the lock are.
>
> 1) A whole load of sshd errors for one of those flood attacks which try
> multiple usersnames. This is not unusual, all my systems with an external
> ssh port see this.
>
> 2) Four 'Watchdog timeout occurreed, resetting!" messages from if_bce.c.
> These are new - without your patch I did not get these.
>
> I have tried rnning this machine with WITNESS in the kernel, but it
> will not deadlock then. Without WiTNESS it will lock up in about
> twelve hours. I am going to try with just KDB and DDB to see if I can get
> it into a state where we can get some useful information out of it.

Also enable INVARIANTS.
While there (with my patch applied) please setup textdump in order to
report the following DDB commands (and once it deadlocks break in
DDB):
bt, show allpcpu, ps, alltrace, show alllocks

Try also to get a coredump (and if you can't report immediately to us
and try to not turn off the machine in order to apply following
instructions).

Attilio


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