alpha/105134: 'panic: lockmgr: thread ... not exclusive lock owner' on SMP Alpha EV6 machine

[Kevin Thompson]

The following reply was made to PR alpha/105134; it has been noted by GNATS.

From: "Kevin Thompson" <kevin at antiduh.com>
To: bug-followup at freebsd.org, antiduh at csh.rit.edu
Cc:  
Subject: Re: alpha/105134: 'panic: lockmgr: thread ... not exclusive lock owner' on SMP Alpha EV6 machine
Date: Tue, 07 Nov 2006 13:08:17 -0500

 I turned on the following kernel options and tried to reproduce it - no  
 luck. I had it running make -j2 buildworld repeatedly and it was still  
 running a day later.
 options         WITNESS
 options         INVARIANTS
 options         INVARIANT_SUPPORT
 options         DIAGNOSTIC
 
 Preemption was still off.
 
 Of mention, I couldn't get the kernel to compile with options DEBUG_LOCKS  
 on.
 The only output that I got every once in a while were the following:
 Expensive timeout(9) function: 0xfffffc00005f7820(0) 0.002491656 s
 Expensive timeout(9) function: 0xfffffc000054f7c0(0xfffffc005f928810)  
 0.010740188 s
 Expensive timeout(9) function: 0xfffffc00005746e0(0) 0.011898436 s
 Expensive timeout(9) function: 0xfffffc000054f7c0(0xfffffc005f929830)  
 0.012660264 s
 
 I'm going to try to turn PREEMPTION back on and see if I can reproduce it.
 
 --Kevin