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SubjectRe: [PATCH 11/11] x86/mm, pat: convert pat tree to generic interval tree

* Davidlohr Bueso <> wrote:

> With some considerations, the custom pat_rbtree implementation can be
> simplified to use most of the generic interval_tree machinery.
> o The tree inorder traversal can slightly differ when there are key
> ('start') collisions in the tree due to one going left and another right.
> This, however, only affects the output of debugfs' pat_memtype_list file.
> o Generic interval trees are now semi open [a,b), which suits well with
> what pat wants.
> o Erasing logic must remain untouched as well.
> In order for the types to remain u64, the 'memtype_interval' calls are
> introduced, as opposed to simply using struct interval_tree.
> In addition, pat tree might potentially also benefit by the fast overlap
> detection for the insertion case when looking up the first overlapping node
> in the tree.
> Finally, I've tested this on various servers, via sanity warnings, running
> side by side with the current version and so far see no differences in the
> returned pointer node when doing memtype_rb_lowest_match() lookups.
> Cc: Peter Zijlstra <>
> Cc: Thomas Gleixner <>
> Cc: Ingo Molnar <>
> Cc: Borislav Petkov <>
> Cc:
> Signed-off-by: Davidlohr Bueso <>
> ---
> arch/x86/mm/pat.c | 22 +++----
> arch/x86/mm/pat_rbtree.c | 151 ++++++++++-------------------------------------
> 2 files changed, 43 insertions(+), 130 deletions(-)

I suppose this will be carried in -mm?

If so and if this patch is regression free, then:

Acked-by: Ingo Molnar <>



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