5.4-RC2 freezing - ATA related?

[Elliot Finley]

From: "Peter Jeremy" <PeterJeremy at optushome.com.au>
> On Wed, 2005-May-18 06:43:37 -0600, Elliot Finley wrote:
> >Had the system lock up again.  This is with the new ATA mkIII patches on
> >http://people.freebsd.org/~sos/ATA.
> >
> >I didn't get the crashdump (forgot to set dumpdev), but I did get 'ps'
and
> >'show lockedvnods' output from DDB.  The output is in the form of
> >screenshots combined into a single .pdf which can be accessed here
> >http://www.efinley.com/Binder1.pdf
>
> That shows a deadlock-to-root in your /dev/ar0s1a (presumably root)
> filesystem.  The perl process (pid 487) has an exclusive lock on
> the FS mountpoint - this is blocking 130 other processes.  Pid 487
> is itself waiting on another filesystem lock (you can't determine
> the actual lock tree without more poking around kernel memory).
>
> The vnode locks are held by processes:
>  PID   name        waiting on
>  487  perl       [ufs c3c1c1b4]
>   57  syncer     [snaplk c535f500]  (holds 2 locks)
>  476  perl       [ufs c87e4f1c]
>  489  perl       [snaplk c535f500]  (holds 2 locks)
> 3337  mksnap_ffs [getblk d77656f4]
>
> Looking through the process list, cron has started a "dump -L" which
> is trying to create a filesystem snapshot.  That has wedged on
> "getblk" (trying to perform physical disk I/O) and is probably the
> root of your problem.  Nothing else is waiting on physical I/O.
>
> I'd say that your first guess was right:  This is a bug in the ATA
> code and is probably a job for sos.

I took the -L option off of my dump command in my daily dump script.  I've
gone two days without locking up which is unusual.  I think that may be what
was tickling the bug that was locking me up.

Thanks for the analysis Peter.

Elliot