Re: linux-next: slab shrinkers: BUG at mm/list_lru.c:92

[Dave Chinner <david@fromorbit.com>]

On Sun, Jun 23, 2013 at 03:51:29PM +0400, Glauber Costa wrote:
> On Fri, Jun 21, 2013 at 11:00:21AM +0200, Michal Hocko wrote:
> > On Thu 20-06-13 17:12:01, Michal Hocko wrote:
> > > I am bisecting it again. It is quite tedious, though, because good case
> > > is hard to be sure about.
> > 
> > OK, so now I converged to 2d4fc052 (inode: convert inode lru list to generic lru
> > list code.) in my tree and I have double checked it matches what is in
> > the linux-next. This doesn't help much to pin point the issue I am
> > afraid :/
> > 
> Can you revert this patch (easiest way ATM is to rewind your tree to a point
> right before it) and apply the following patch?
> 
> As Dave has mentioned, it is very likely that this bug was already there, we
> were just not ever checking imbalances. The attached patch would tell us at
> least if the imbalance was there before. If this is the case, I would suggest
> turning the BUG condition into a WARN_ON_ONCE since we would be officially
> not introducing any regression. It is no less of a bug, though, and we should
> keep looking for it.

We probably should do that BUG->WARN change anyway. BUG_ON is pretty
obnoxious in places where we can probably continue on without much
impact....

Cheers,

Dave.
-- 
Dave Chinner
david@fromorbit.com