lkml.org 
[lkml]   [2012]   [Jan]   [9]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    From
    SubjectRe: [RFC PATCH] shrink_dcache_parent() deadlock
    Date
    Linus Torvalds <torvalds@linux-foundation.org> writes:

    > On Mon, Jan 9, 2012 at 2:58 AM, Miklos Szeredi <miklos@szeredi.hu> wrote:
    >>
    >> This patch adds a new dentry flag that is set when the dentry is removed
    >> from the lru and put on the list being processed by
    >> shrink_dentry_list().  The flag is cleared in dentry_lru_del() which is
    >> called if the dentry gets a new reference just before it's pruned.
    >>
    >> Thoughts?
    >
    > Looks reasonable. Were you actually able to reproduce the hang, or how
    > did you notice?

    We got a bug report from a partner about hang during reboot. It's
    actually quite easily reproducible with:

    while true; do
    echo -bond0 > /sys/class/net/bonding_masters
    echo +bond0 > /sys/class/net/bonding_masters
    echo -bond1 > /sys/class/net/bonding_masters
    echo +bond1 > /sys/class/net/bonding_masters
    done

    That reliably triggers the soft lookup detector for several machines
    that we tested. It's rather timing sensitive though, because turning on
    DEBUG_SPINLOCK makes it go away.

    I had to add printks to see what's going on, because it wasn't obvious
    from the stack traces and crash dumps.

    Thanks,
    Miklos
    --
    To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
    the body of a message to majordomo@vger.kernel.org
    More majordomo info at http://vger.kernel.org/majordomo-info.html
    Please read the FAQ at http://www.tux.org/lkml/

    \
     
     \ /
      Last update: 2012-01-09 18:09    [W:0.025 / U:67.372 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site