Re: page fault panic tracked down (selwakeuppri())

On Tue, 2003-12-30 at 07:56, Bruce Evans wrote:
> On Sun, 28 Dec 2003, Stefan Ehmann wrote:
> 
> > Some weeks ago I posted about a panic in 5.2-BETA.
> >
> > After accessing a read-only ext2fs for some hours I got a "page fault"
> > panic (or rarely a "getblk: size(7537385) > MAXBSIZE(65536)"). The
> > backtrace was always somewhat different. You can read about it a bit
> > more detailed here:
> >
> > http://lists.freebsd.org/pipermail/freebsd-current/2003-November/015405.html
> >
> > After lots of buildworld and buildkernel I finally was able to detect
> > the commit that caused this panic.
> >
> > Current from 2003.11.09.09.00.00 runs fine for > 10 hours. Current from
> > 2003.11.09.09.20.00 crashed twice within less than 2 hours.
> >
> > The only src/sys commit in that time is
> > http://lists.freebsd.org/pipermail/cvs-src/2003-November/013515.html
> > where selwakeup()s is replaced with selwakeuppri().
> >
> > So the problem must be somewhere in selwakeuppri().
> >
> > I hope this can be resolved now.
> 
> The selwakeuppri() changes aren't very related to this.  They shouldn't
> affect anything except scheduling, so it looks like they just expose an
> old race.
> 
> I suspect the locking changes on 2003/08/28 (ext2fs/fs.h rev.1.14
> etc.).  These were obviously wrong since they broke syncing of dirty
> buffers, especially at reboot time, but I didn't previously suspect
> that they had locking problems.  The message in the above URL doesn't
> seem to have much to do with ext2fs, but it shows a panic in lockmgr()
> and the 2003/08/28 changes cause lockmgr() to be used with a different
> owner.
> 
> I have farily large patches which do buffering in ext2fs in a different
> way so that the 2003/08/28 changes are irrelevant.  I will send these
> in private mail.

Applied the patches and rebuilt kernel. Unfortunately I got the same
panic after 2 hours.