Messages in this thread | | | Date | Tue, 22 Jun 2010 10:45:36 +0800 | From | Xiaotian Feng <> | Subject | Re: [patch] x86, pat: freeing invalid memtype messages |
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On 06/22/2010 01:54 AM, Suresh Siddha 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.
Were it from a insert without any rotations/color changes?
This case is performing insert A/remove A/ 2nd insert A/ 2nd remove A/3rd insert A. And the 2nd remove shows us the invalid memtype. 3rd insert shows us it is in the rbtree. All I can image is that get_subtree_max_end in memtype_rb_lowest_match returned stale value.
It looks like we don't re-augment the parent nodes if there aren't any rotations/color changes in the rb_insert_color().
> > thanks, > suresh > >
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