Re: Mutex error: mutex_vector_enter: locking against myself

[eric%cirr.com@localhost (Eric Schnoebelen)]

NONAKA Kimihiro writes:
- Today's -current panic when shutdown.
- For more information, please see the attached file.

I've been seeing this error with XEN DomU's for the last several
moths. I have console logs from early May, and saw it happen
this morning with 

NetBSD egsner.cirr.com 5.99.51 NetBSD 5.99.51 (XEN3_DOMU) #4: Fri May 20 
01:48:52 CDT 2011 
eric%bob-the-builder.cirr.com@localhost:/work/eric/NetBSD-current/obj/amd64/sys/arch/amd64/compile/XEN3_DOMU
 amd64

I haven't tried any of this month's kernels.

No tracebacks, just the following panic messages:

---
Reader / writer lock error: rw_vector_enter: locking against myself

lock address : 0xffffa0004d7887d0
current cpu  :                  0
current lwp  : 0xffffa0005f13f440
owner/count  : 0xffffa0005f13f440 flags    : 0x0000000000000004

panic: lock error
cpu0: Begin traceback...
uvm_fault(0xffffa0004922a478, 0x0, 1) -> e
fatal page fault in supervisor mode
trap type 6 code 0 rip ffffffff8013719f cs e030 rflags 10246 cr2  d cpl 0 rsp 
ffffa000493042d0
Skipping crash dump on recursive panic
panic: trap
Faulted in mid-traceback; aborting...rebooting...
---
Reader / writer lock error: rw_vector_enter: locking against myself

lock address : 0xffffa00050862350
current cpu  :                  0
current lwp  : 0xffffa0004965c900
owner/count  : 0xffffa0004965c900 flags    : 0x0000000000000004

panic: lock error
cpu0: Begin traceback...
uvm_fault(0xffffa000496b8480, 0x0, 1) -> e
fatal page fault in supervisor mode
trap type 6 code 0 rip ffffffff8013719f cs e030 rflags 10246 cr2  d cpl 0 rsp 
ffffa00047c502d0
Skipping crash dump on recursive panic
panic: trap
Faulted in mid-traceback; aborting...rebooting...
---
Reader / writer lock error: rw_vector_enter: locking against
myself

lock address : 0xffffa0004ae316a8
current cpu  :                  0
current lwp  : 0xffffa0004ff21160
owner/count  : 0xffffa0004ff21160 flags    : 0x0000000000000004

panic: lock error
cpu0: Begin traceback...
uvm_fault(0xffffa0004feef310, 0x0, 1) -> e
fatal page fault in supervisor mode
trap type 6 code 0 rip ffffffff8013719f cs e030 rflags 10246 cr2  d cpl 0 rsp 
ffffa0004ff072d0
Skipping crash dump on recursive panic
panic: trap
Faulted in mid-traceback; aborting...rebooting...
---

Does any of the above help isolate the cause..

Interesting tidbits about this system.  Null mounts, NFS server,
XEN DomU.

--
Eric Schnoebelen                eric%cirr.com@localhost         
http://www.cirr.com
    I sometimes wonder why I bother waking up in the morning. It would
    save so much time if I just admitted defeat and stayed asleep, and
    the results could hardly be much different.... -- Brian Pickering