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authorWei Yang <richardw.yang@linux.intel.com>2019-12-04 16:51:47 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2019-12-04 19:44:13 -0800
commit11d43e62f693c66c8c76c2ea2349e0f3c5764964 (patch)
treec9ee0fa1a402360641bc1d0275961a8ac87cea04 /include
parentae81217edc18135d13e5b6c17609ee2c07af4188 (diff)
downloadlinux-11d43e62f693c66c8c76c2ea2349e0f3c5764964.tar.bz2
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@linux.intel.com Signed-off-by: Wei Yang <richardw.yang@linux.intel.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Michel Lespinasse <walken@google.com> Reviewed-by: Davidlohr Bueso <dbueso@suse.de> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include')
-rw-r--r--include/linux/rbtree_augmented.h3
1 files changed, 1 insertions, 2 deletions
diff --git a/include/linux/rbtree_augmented.h b/include/linux/rbtree_augmented.h
index fdd421b8d9ae..99c42e1a74b8 100644
--- a/include/linux/rbtree_augmented.h
+++ b/include/linux/rbtree_augmented.h
@@ -283,14 +283,13 @@ __rb_erase_augmented(struct rb_node *node, struct rb_root *root,
__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;
}