Re: [patch] x86, pat: freeing invalid memtype messages

[Marcin Slusarz <marcin.slusarz@gmail.com>]

On Mon, Jun 21, 2010 at 11:38:27AM -0700, Venkatesh Pallipadi wrote:
> On Mon, Jun 21, 2010 at 11:08 AM, Venkatesh Pallipadi <venki@google.com> wrote:
> > On Mon, Jun 21, 2010 at 10:54 AM, Suresh Siddha
> > <suresh.b.siddha@intel.com> wrote:
> >> On Mon, 2010-06-21 at 08:41 -0700, Peter Zijlstra wrote:
> >>> On Mon, 2010-06-21 at 17:33 +0200, Marcin Slusarz wrote:
> >>> > On Mon, Jun 21, 2010 at 07:07:27PM +0800, Xiaotian Feng wrote:
> >>> > > On 06/21/2010 07:02 PM, Peter Zijlstra wrote:
> >>> > > > On Mon, 2010-06-21 at 18:56 +0800, Xiaotian Feng wrote:
> >>> > > >
> >>> > > >> I guess there might be something wrong between the augmented rbtree insert/remove ..
> >>> > > >
> >>> > > > The easiest thing is to revert that change and try again, the next step
> >>> > > > would be to print the full RB tree on each modification and look where
> >>> > > > it goes wrong.
> >>> > > >
> >>> > > > That said, I did print my fair share of (augmented) RB trees while
> >>> > > > playing with scheduler patches and I can't remember it ever having
> >>> > > > messed up like that.
> >>> > > He's using 2.6.35-rc2+, without your "rbtree: Undo augmented trees
> >>> > > performance damage" patch ;-)
> >>> >
> >>> > I applied it manually (commit 2463eb8b3093995e09a0d41b3d78ee0cf5fb4249 from -tip)
> >>> > to 2.6.35-rc3 and it fixed both acpi's and nouveau's "invalid memtype" messages.
> >>> > Thanks.
> >>>
> >>> Oh neat, so it actually fixes a bug in the previous augmented rb-tree
> >>> implementation?
> >>
> >> When I was reviewing your fix, it looked like that prior to your fix we
> >> were re-augmenting only at points where we do the tree rotations/color
> >> change and at the points of node insertion/removal. I don't think we
> >> were re-augmenting all the parent nodes in the path of the selected-node
> >> that is going to replace the deleted node.
> >>
> >> Perhaps we were hitting this issue here.
> >>
> >
> > rb_erase was calling the augment callback with successor_parent_cb.
> > That should be doing proper re-augmenting on delete.
> >
> > May be we are hitting the problem with not-initializing
> > subtree_max_end on insert? That was fixed in a later patch.
> 
> Here's the patch I was referring to
> http://marc.info/?l=linux-mm-commits&m=127654225011850&w=2
> 
> Marcin: Can you try this patch without Peter's patch and see whether
> there are any issues with that. Just to make sure we don't have issues
> wuth underlying augmented rbtree algorithm that somehow got fixed or
> masked for the time being with Peter's change.

I tested this patch few days ago and it produced even more "invalid memtype" messages...

Marcin