The patch titled
Subject: lib/rbtree: set successor's parent unconditionally
has been added to the -mm tree. Its filename is
lib-rbtree-set-successors-parent-unconditionally.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/lib-rbtree-set-successors-parent-unconditionally.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/lib-rbtree-set-successors-parent-unconditionally.patch
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------------------------------------------------------
From: Wei Yang <richardw.yang@xxxxxxxxxxxxxxx>
Subject: lib/rbtree: set successor's parent unconditionally
Both in Case 2 and 3, we exchange n and s. This mean no matter whether
child2 is NULL or not, successor's parent should be assigned to node's.
This patch takes this step out to make it explicit and reduce the
ambiguity.
Besides, this step reduces some symbol size like rb_erase().
KERN_CONFIG upstream patched
OPT_FOR_PERF 877 870
OPT_FOR_SIZE 635 621
Link: http://lkml.kernel.org/r/20191028021442.5450-1-richardw.yang@xxxxxxxxxxxxxxx
Signed-off-by: Wei Yang <richardw.yang@xxxxxxxxxxxxxxx>
Acked-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Reviewed-by: Michel Lespinasse <walken@xxxxxxxxxx>
Cc: Davidlohr Bueso <dave@xxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/rbtree_augmented.h | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
--- a/include/linux/rbtree_augmented.h~lib-rbtree-set-successors-parent-unconditionally
+++ a/include/linux/rbtree_augmented.h
@@ -283,14 +283,13 @@ __rb_erase_augmented(struct rb_node *nod
__rb_change_child(node, successor, tmp, root);
if (child2) {
- successor->__rb_parent_color = pc;
rb_set_parent_color(child2, parent, RB_BLACK);
rebalance = NULL;
} else {
unsigned long pc2 = successor->__rb_parent_color;
- successor->__rb_parent_color = pc;
rebalance = __rb_is_black(pc2) ? parent : NULL;
}
+ successor->__rb_parent_color = pc;
tmp = successor;
}
_
Patches currently in -mm which might be from richardw.yang@xxxxxxxxxxxxxxx are
mm-mmapc-remove-a-never-trigger-warning-in-__vma_adjust.patch
mm-mmapc-prev-could-be-retrieved-from-vma-vm_prev.patch
mm-mmapc-__vma_unlink_prev-is-not-necessary-now.patch
mm-mmapc-extract-__vma_unlink_list-as-counter-part-for-__vma_link_list.patch
mm-mmapc-rb_parent-is-not-necessary-in-__vma_link_list.patch
mm-rmapc-dont-reuse-anon_vma-if-we-just-want-a-copy.patch
mm-rmapc-reuse-mergeable-anon_vma-as-parent-when-fork.patch
hugetlb-remove-unused-hstate-in-hugetlb_fault_mutex_hash.patch
mm-mmapc-make-vma_merge-comment-more-easy-to-understand.patch
userfaultfd-use-vma_pagesize-for-all-huge-page-size-calculation.patch
userfaultfd-remove-unnecessary-warn_on-in-__mcopy_atomic_hugetlb.patch
userfaultfd-wrap-the-common-dst_vma-check-into-an-inlined-function.patch
mm-fix-typo-in-the-comment-when-calling-function-__setpageuptodate.patch
lib-rbtree-set-successors-parent-unconditionally.patch
lib-rbtree-get-successors-color-directly.patch
