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

From: Bruce Evans (bde_at_zeta.org.au)
Date: 12/30/03

  • Next message: mcabanatuan_at_wi.rr.com: "updating ports collection" 
    Date: Tue, 30 Dec 2003 17:56:20 +1100 (EST)
To: Stefan Ehmann <shoesoft@gmx.net>

    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.

    Bruce
    _______________________________________________
    freebsd-current@freebsd.org mailing list
    http://lists.freebsd.org/mailman/listinfo/freebsd-current
    To unsubscribe, send any mail to "freebsd-current-unsubscribe@freebsd.org"

  • Next message: mcabanatuan_at_wi.rr.com: "updating ports collection"

    Relevant Pages