The patch titled Subject: rbtree: optimize case selection logic in __rb_erase_color() has been removed from the -mm tree. Its filename was rbtree-optimize-case-selection-logic-in-__rb_erase_color.patch This patch was dropped because it was merged into mainline or a subsystem tree ------------------------------------------------------ From: Michel Lespinasse <walken@xxxxxxxxxx> Subject: rbtree: optimize case selection logic in __rb_erase_color() In __rb_erase_color(), we have to select one of 3 cases depending on the color on the 'other' node children. If both children are black, we flip a few node colors and iterate. Otherwise, we do either one or two tree rotations, depending on the color of the 'other' child opposite to 'node', and then we are done. The corresponding logic had duplicate checks for the color of the 'other' child opposite to 'node'. It was checking it first to determine if both children are black, and then to determine how many tree rotations are required. Rearrange the logic to avoid that extra check. Signed-off-by: Michel Lespinasse <walken@xxxxxxxxxx> Cc: Andrea Arcangeli <aarcange@xxxxxxxxxx> Acked-by: David Woodhouse <David.Woodhouse@xxxxxxxxx> Cc: Rik van Riel <riel@xxxxxxxxxx> Cc: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx> Cc: Daniel Santos <daniel.santos@xxxxxxxxx> Cc: Jens Axboe <axboe@xxxxxxxxx> Cc: "Eric W. Biederman" <ebiederm@xxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- lib/rbtree.c | 68 +++++++++++++++++++++---------------------------- 1 file changed, 30 insertions(+), 38 deletions(-) diff -puN lib/rbtree.c~rbtree-optimize-case-selection-logic-in-__rb_erase_color lib/rbtree.c --- a/lib/rbtree.c~rbtree-optimize-case-selection-logic-in-__rb_erase_color +++ a/lib/rbtree.c @@ -283,28 +283,24 @@ static void __rb_erase_color(struct rb_n __rb_rotate_left(parent, root); other = parent->rb_right; } - if ((!other->rb_left || rb_is_black(other->rb_left)) && - (!other->rb_right || rb_is_black(other->rb_right))) - { - rb_set_red(other); - node = parent; - parent = rb_parent(node); - } - else - { - if (!other->rb_right || rb_is_black(other->rb_right)) - { - rb_set_black(other->rb_left); + if (!other->rb_right || rb_is_black(other->rb_right)) { + if (!other->rb_left || + rb_is_black(other->rb_left)) { rb_set_red(other); - __rb_rotate_right(other, root); - other = parent->rb_right; + node = parent; + parent = rb_parent(node); + continue; } - rb_set_color(other, rb_color(parent)); - rb_set_black(parent); - rb_set_black(other->rb_right); - __rb_rotate_left(parent, root); - break; + rb_set_black(other->rb_left); + rb_set_red(other); + __rb_rotate_right(other, root); + other = parent->rb_right; } + rb_set_color(other, rb_color(parent)); + rb_set_black(parent); + rb_set_black(other->rb_right); + __rb_rotate_left(parent, root); + break; } else { other = parent->rb_left; if (rb_is_red(other)) @@ -314,28 +310,24 @@ static void __rb_erase_color(struct rb_n __rb_rotate_right(parent, root); other = parent->rb_left; } - if ((!other->rb_left || rb_is_black(other->rb_left)) && - (!other->rb_right || rb_is_black(other->rb_right))) - { - rb_set_red(other); - node = parent; - parent = rb_parent(node); - } - else - { - if (!other->rb_left || rb_is_black(other->rb_left)) - { - rb_set_black(other->rb_right); + if (!other->rb_left || rb_is_black(other->rb_left)) { + if (!other->rb_right || + rb_is_black(other->rb_right)) { rb_set_red(other); - __rb_rotate_left(other, root); - other = parent->rb_left; + node = parent; + parent = rb_parent(node); + continue; } - rb_set_color(other, rb_color(parent)); - rb_set_black(parent); - rb_set_black(other->rb_left); - __rb_rotate_right(parent, root); - break; + rb_set_black(other->rb_right); + rb_set_red(other); + __rb_rotate_left(other, root); + other = parent->rb_left; } + rb_set_color(other, rb_color(parent)); + rb_set_black(parent); + rb_set_black(other->rb_left); + __rb_rotate_right(parent, root); + break; } } } _ Patches currently in -mm which might be from walken@xxxxxxxxxx are origin.patch prio_tree-remove-fix.patch -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html