maple_tree: combine_separate reduction with parents and cp_left/cp_right

Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com>

diff --git a/lib/maple_tree.c b/lib/maple_tree.c
index 5f9d20c5e3e19981219d6d4798ca06247da6d18c..ff4ab65bfc4334f97f58a9f1a05e1e09ca8e5847 100644 (file)
--- a/lib/maple_tree.c
+++ b/lib/maple_tree.c
@@ -114,6 +114,7 @@ struct maple_subtree_state {
        struct ma_state *orig_l;        /* Original left side of subtree */
        struct ma_state *orig_r;        /* Original rigth side of subtree */
        struct ma_state *l;             /* New left side of subtree */
+       struct ma_state *m;             /* New middle of subtree (rare) */
        struct ma_state *r;             /* New right side of subtree */
        struct ma_topiary *free;        /* nodes to be freed */
        struct ma_topiary *destroy;     /* Nodes to be destroyed (walked and freed) */
@@ -1967,6 +1968,17 @@ static inline void mas_set_split_parent(struct ma_state *mas,
        (*slot)++;
 }
 
+static inline void mast_set_split_parents(struct maple_subtree_state *mast,
+                                         struct maple_enode *left,
+                                         struct maple_enode *right,
+                                         unsigned char split)
+{
+       unsigned char slot = mas_get_slot(mast->l);
+
+       mas_set_split_parent(mast->l, left, right, &slot, split);
+       mas_set_split_parent(mast->m, left, right, &slot, split);
+       mas_set_split_parent(mast->r, left, right, &slot, split);
+}
 static inline void mas_wmb_replace(struct ma_state *mas,
                                   struct ma_topiary *free,
                                   struct ma_topiary *destroy)
@@ -2016,6 +2028,24 @@ static inline bool mast_new_root(struct maple_subtree_state *mast,
        mas_dup_state(mast->orig_l, mast->l);
        return true;
 }
+static inline void mast_combine_cp_left(struct maple_subtree_state *mast)
+{
+       unsigned char l_slot = mas_get_slot(mast->orig_l);
+
+       if (!l_slot)
+               return;
+
+       mas_mab_cp(mast->orig_l, 0, l_slot - 1, mast->bn, 0);
+}
+static inline void mast_combine_cp_right(struct maple_subtree_state *mast)
+{
+       if (mast->bn->pivot[mast->bn->b_end - 1] >= mast->orig_r->max)
+               return;
+
+       mas_mab_cp(mast->orig_r, mas_get_slot(mast->orig_r) + 1,
+                  mas_data_end(mast->orig_r), mast->bn, mast->bn->b_end);
+       mast->orig_r->last = mast->orig_r->max;
+}
 /* Private
  *
  * mas_combine_separate() - Follow the tree upwards from @l_mas and @r_mas for
@@ -2037,7 +2067,7 @@ static inline int mas_combine_separate(struct ma_state *mas,
                                       struct maple_subtree_state *mast, unsigned char count)
 {
        unsigned char split, mid_split;
-       unsigned char slot = 0, l_slot = 0;
+       unsigned char slot = 0;
        struct maple_enode *left = NULL, *middle = NULL, *right = NULL;
 
        MA_STATE(l_mas, mas->tree, mas->index, mas->index);
@@ -2047,6 +2077,7 @@ static inline int mas_combine_separate(struct ma_state *mas,
        MA_TOPIARY(destroy, mas->tree);
 
        mast->l = &l_mas;
+       mast->m = &m_mas;
        mast->r = &r_mas;
        mast->free = &free;
        mast->destroy = &destroy;
@@ -2062,11 +2093,7 @@ static inline int mas_combine_separate(struct ma_state *mas,
                split = mas_mab_to_node(mas, mast->bn, &left, &right, &middle,
                                        &mid_split);
 
-               /* Set parents from previous run */
-               slot = mas_get_slot(&l_mas);
-               mas_set_split_parent(&l_mas, left, right, &slot, split);
-               mas_set_split_parent(&m_mas, left, right, &slot, split);
-               mas_set_split_parent(&r_mas, left, right, &slot, split);
+               mast_set_split_parents(mast, left, right, split);
 
                /* Copy data from mast->bn to new nodes */
                l_mas.node = left;
@@ -2098,11 +2125,9 @@ static inline int mas_combine_separate(struct ma_state *mas,
                        goto new_root;
 
                mast_ascend_free(mast);
-               l_slot = mas_get_slot(mast->orig_l);
 
                mast->bn->b_end = 0;
-               if (l_slot)
-                       mas_mab_cp(mast->orig_l, 0, l_slot - 1, mast->bn, 0);
+               mast_combine_cp_left(mast);
 
                mas_set_slot(&l_mas, mast->bn->b_end);
                mab_set_b_end(mast->bn, &l_mas, left);
@@ -2110,12 +2135,7 @@ static inline int mas_combine_separate(struct ma_state *mas,
                mab_set_b_end(mast->bn, &r_mas, right);
 
                // Copy anything necessary out of the right node.
-               if (mast->bn->pivot[mast->bn->b_end - 1] < mast->orig_r->max) {
-                       mas_mab_cp(mast->orig_r, mas_get_slot(mast->orig_r) + 1,
-                                  mas_data_end(mast->orig_r), mast->bn,
-                                  mast->bn->b_end);
-                       mast->orig_r->last = mast->orig_r->max;
-               }
+               mast_combine_cp_right(mast);
                mast_consume(mast);
                mast->orig_l->last = mast->orig_l->max;