3.14.0-rc2: WARNING: at mm/slub.c:1007

[Dave Chinner]

On Thu, Feb 13, 2014 at 11:53:05AM -0800, Christian Kujau wrote:
> Hi,
> 
> after upgrading from 3.13-rc8 to 3.14.0-rc2 on this PowerPC G4 machine, 
> the WARNING below was printed.
> 
> Shortly after, a lockdep warning appeared (possibly related to my 
> post to the XFS list yesterday[0]).

Unlikely.

> Even later in the log an out-of-memory error appeared, that may or may not 
> be relatd to that WARNING at all but which I'm trying to chase down ever 
> since 3.13, but which tends to appear more often lately.
> 
> Can anyone take a look if this is something to worry about?

Already fixed upstream:

commit 255d0884f5635122adb23866b242b4ca112f4bc8
Author: David Rientjes <rientjes at google.com>
Date:   Mon Feb 10 14:25:39 2014 -0800

    mm/slub.c: list_lock may not be held in some circumstances
    
    Commit c65c1877bd68 ("slub: use lockdep_assert_held") incorrectly
    required that add_full() and remove_full() hold n->list_lock.  The lock
    is only taken when kmem_cache_debug(s), since that's the only time it
    actually does anything.
    
    Require that the lock only be taken under such a condition.
    
    Reported-by: Larry Finger <Larry.Finger at lwfinger.net>
    Tested-by: Larry Finger <Larry.Finger at lwfinger.net>
    Tested-by: Paul E. McKenney <paulmck at linux.vnet.ibm.com>
    Acked-by: Christoph Lameter <cl at linux.com>
    Cc: Pekka Enberg <penberg at kernel.org>
    Signed-off-by: David Rientjes <rientjes at google.com>
    Signed-off-by: Andrew Morton <akpm at linux-foundation.org>
    Signed-off-by: Linus Torvalds <torvalds at linux-foundation.org>


Cheers,

Dave.

-- 
Dave Chinner
david at fromorbit.com