Skip site navigation (1)Skip section navigation (2)
Date:      Wed, 19 Sep 2001 13:32:28 -0700 (PDT)
From:      John Baldwin <jhb@FreeBSD.org>
To:        Wilko Bulte <wkb@freebie.xs4all.nl>
Cc:        current@FreeBSD.org, Garrett Wollman <wollman@khavrinen.lcs.mit.edu>
Subject:   Re: Seen this lock order reversal?
Message-ID:  <XFMail.010919133228.jhb@FreeBSD.org>
In-Reply-To: <20010919202447.B1763@freebie.xs4all.nl>

next in thread | previous in thread | raw e-mail | index | archive | help

On 19-Sep-01 Wilko Bulte wrote:
> On Tue, Sep 18, 2001 at 03:01:25PM -0700, John Baldwin wrote:
>> 
>> On 18-Sep-01 Garrett Wollman wrote:
>> > lock order reversal
>> >  1st 0xd3a5c11c process lock @ ../../../vm/vm_glue.c:469
>> >  2nd 0xc0e3fe30 lockmgr interlock @ ../../../kern/kern_lock.c:239
>> > 
>> > This is on relatively old (~ three months) sources.  The first lock is
>> > from swapout_procs(); I assume the second lock actually refers to the
>> > call to lockmgr(&vm->vm_map.lock, ...) further down in the same
>> > function.  If this has been fixed already, let me know.  (It doesn't
>> > seem to have hurt anything.)
>> 
>> It is old, but I think it has been fixed recently as a side effect of the
>> KSE
>> commit.  (In terms of the pre-KSE kernel, the P_DEADLKTREAT flag moved from
>> p_flag to p_sflag which changed its locking semantics.)
> 
> Another one, on a -current from yesterday, on -alpha:
> 
> lock order reversal
>  1st 0xfffffc00007fcef0 clk @ ../../../alpha/alpha/clock.c:702
>  2nd 0xfffffc00007f65d8 callout @ ../../../kern/kern_timeout.c:225
> ds10#

Hmm, ok, that one is new and is a problem.  Can you turn on WITNESS_DDB (it's
available as the debug.witness_ddb sysctl and loader variableas well) and then
get me a traceback in ddb?

-- 

John Baldwin <jhb@FreeBSD.org> -- http://www.FreeBSD.org/~jhb/
PGP Key: http://www.baldwin.cx/~john/pgpkey.asc
"Power Users Use the Power to Serve!"  -  http://www.FreeBSD.org/

To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe freebsd-current" in the body of the message




Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?XFMail.010919133228.jhb>