UFS/VFS lock order reversal on stock 8.0-200812-AMD64

[Gavin Atkinson]

On Fri, 2009-01-23 at 12:28 -0600, Paul Tice wrote:
> -----Original Message-----
> From: Gavin Atkinson [mailto:gavin at FreeBSD.org]
> Sent: Fri 1/23/2009 6:19 AM
> To: Paul Tice
> Cc: freebsd-current at FreeBSD.org
> Subject: Re: UFS/VFS lock order reversal on stock 8.0-200812-AMD64
>  
> On Fri, 2009-01-23 at 12:07 +0000, Gavin Atkinson wrote:
> > On Thu, 2009-01-22 at 21:33 -0600, Paul Tice wrote:
> > > I'm new, so please advise me (gently?) about list protocol and such if needed.
> > > 
> > > Using stock 8.0-CURRENT-200812-amd64, I am getting the messages below.
> > 
> > 8.0-CURRENT is essentially the bleeding-edge of FreeBSD, and is where
> > development happens that has not necessarily proven itself as being
> > stable.  As it is the development branch, it also has a lot of extra
> > debugging enabled, which is what you are seeing with the "lock order
> > reversals".
> > 
> > If you are not running 8-CURRENT for a specific reason (e.g. because you
> > are doing FreeBSD OS development work, or you are prepared to help debug
> > issues as you encounter them, or similar), you probably shouldn't be
> > running CURRENT.  Stick with 7.1.
> 
> >I should have also included (in answer to your actual question):
> >Neither the lock order reversals or the corrupted messages on shutdown
> >are anything you need worry about.
> 
> >Gavin
> 
> 
> I wouldn't have asked if I wasn't willing to help debug (as possible, and with very little coding knowledge.)

Cool.  It's always good to have more people using and testing -CURRENT,
I just wanted to make sure you knew what you were getting yourself in
for :)

> I pulled out the 'extra debugging', made world and kernel, and rebooted.
> Notice the 5th line of da7's drive ID being interleaved with 'SMP: AP CPU #1 Launched!'
> 
> I'm fairly sure this is not a good thing, if for no other reason that 'apparent garbage' in dmesg is not useful.

It's not a good thing, but it's a known issue and is purely cosmetic.

Gavin