maple_tree: Add support for combining gaps.

When gaps touch but are not in the same node, move them to the right
node.  This allows for searches to find the desired gap.

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

diff --git a/lib/maple_tree.c b/lib/maple_tree.c
index d448bcb69bce620d79562b57249f513aef598a48..d6eaeac816b0912ac8680d791986bf88f716fcd7 100644 (file)
--- a/lib/maple_tree.c
+++ b/lib/maple_tree.c
@@ -893,6 +893,47 @@ restart:
        }
        mte_set_pivot(safe_mas.node, slot, val);
 }
+
+/** Private
+ * mas_shift_pivot() - Shift a pivot from one node to the next.
+ * @left - the left node with mas slot set to the pivot location.
+ * @right - the right node with mas slot set to the pivot location.
+ *
+ * This exists when moving gaps across many levels of a tree.  Basically, walk
+ * backwards until the nodes meet and set the pivots accordingly.
+ *
+ * Special cases for XA_SKIP_ENTRY is needed.
+ */
+static inline void mas_shift_pivot(struct ma_state *curr,
+               struct ma_state *next, unsigned long piv)
+{
+       unsigned char l_p_slot; // left parent slot.
+       unsigned char r_p_slot; // right parent slot.
+
+       MA_STATE(left, curr->tree, curr->index, curr->last);
+       MA_STATE(right, next->tree, next->index, next->last);
+
+       mas_dup_state(&left, curr);
+       mas_dup_state(&right, next);
+       do {
+               // Ends with NULL side
+               l_p_slot = mte_parent_slot(left.node);
+               mas_set_slot(&left, l_p_slot);
+               mas_ascend(&left);
+
+               // Starts with NULL side
+               r_p_slot = mte_parent_slot(right.node);
+               mas_set_slot(&right, r_p_slot);
+               mas_ascend(&right);
+
+               mas_set_safe_pivot(&left, l_p_slot, piv);
+               if (left.node == right.node)
+                       break;
+
+               mas_set_slot(&left, l_p_slot);
+               mas_set_slot(&right, r_p_slot);
+       } while (left.node != right.node);
+}
 /* mas_get_prev_pivot() - Return the previous pivot.
  *
  * Mainly for extracting the previous pivot in the case of slot = 0.
@@ -2148,7 +2189,78 @@ static inline enum maple_type mas_determine_type(struct ma_state *mas,
        return mt;
 }
 
+/** Private
+ * mas_may_move_gap() - May move the gap to the proceeding node.
+ */
+static inline void mas_may_move_gap(struct ma_state *mas)
+{
+
+       unsigned long last_piv;
+       unsigned char coalesce;
+       unsigned char end;
+       unsigned char slot = mas_get_slot(mas);
+       void *entry = NULL;
+
+       // node that starts with NULL
+       MA_STATE(next, mas->tree, mas->index, mas->last);
+       // node that ends with NULL
+       MA_STATE(curr, mas->tree, mas->index, mas->last);
+
+       if (mte_is_root(mas->node))
+               return;
+
+       mas_dup_state(&next, mas);
+       mas_dup_state(&curr, mas);
+       end = mas_data_end(&curr, mte_node_type(curr.node), &last_piv,
+                       &coalesce);
+       if (end != slot) {
+               mas_prev(&curr, 0);
+               if (curr.node == mas->node) // prev value not in prev node.
+                       return;
+       }
+
+       if (mas_is_none(&curr))
+               return;
+
+       end = mas_data_end(&curr, mte_node_type(curr.node), &last_piv,
+                       &coalesce);
+       entry = mas_get_rcu_slot(&curr, end);
+       if (entry && !xa_is_deleted(entry))
+               return;
+
+       if (curr.node == mas->node) {
+               mas_next(&next, ULONG_MAX);
+               if (mas_is_none(&next))
+                       return;
+
+               if (!mt_is_empty(mas_get_rcu_slot(&next, 0)))
+                       return;
+       }
 
+       while (end && (!entry || xa_is_deleted(entry)))
+               entry = mas_get_rcu_slot(&curr, --end);
+
+       last_piv = mas_get_safe_pivot(&curr, end);
+
+       // At this point, mas->node is the one with end slot = NULL
+       // check.node starts with NULL.
+       if (end < mt_pivot_count(curr.node) - 1)
+               mte_set_pivot(curr.node, end + 1, 0);
+
+       if (curr.node == mas->node)
+               mas->max = last_piv;
+       else
+               mas->min = last_piv + 1;
+
+       mas_shift_pivot(&curr, &next, last_piv);
+       next.min = last_piv + 1;
+       curr.max = last_piv;
+
+       if (mt_is_alloc(mas->tree)) {
+               mas_update_gap(&curr, false);
+               mas_update_gap(&next, false);
+       }
+}
 
 static inline int mas_add(struct ma_state *mas, void *entry, bool overwrite,
                bool active);
@@ -2166,8 +2278,7 @@ static inline int _mas_add_dense(struct ma_state *mas, void *entry,
        // FIXME: Check entire range, not what we would insert this time.
        if (!overwrite) {
                do {
-                       if (_mte_get_rcu_slot(mas->node, min++, this_type,
-                                             mas->tree))
+                       if (mas_get_rcu_slot(mas, min++))
                                return 0;
                } while (min < max);
        }
@@ -2275,73 +2386,72 @@ static inline int __mas_add(struct ma_state *mas, void *entry,
        unsigned char coalesce;
        unsigned char data_end = mas_data_end(mas, mas_type, &wr_pivot,
                                              &coalesce);
+       unsigned char slot = mas_get_slot(mas);
+       unsigned char end_slot = slot;
+       unsigned long src_max = mas->max;
+       unsigned long piv, prev_piv = mas->min - 1;
+       void *existing_entry = NULL;
        int ret = 0;
 
+       MA_STATE(cp, mas->tree, mas->index, mas->last);
 
-       if (append) {
+       /* Append only if we are appending AND the slot is truly empty.
+        * If it's delete, skip, etc, then RCU requires a new node.
+        */
+       if (append && !mas_get_rcu_slot(mas, data_end + 1)) {
                mas_set_slot(mas, data_end + 1);
                mas_append_entry(mas, entry);
-       } else {
-               unsigned char slot = mas_get_slot(mas);
-               unsigned char end_slot = slot;
-               unsigned long src_max = mas->max;
-               unsigned long piv, prev_piv = mas->min - 1;
-               void *existing_entry = NULL;
+               return ret;
+       }
 
-               MA_STATE(cp, mas->tree, mas->index, mas->last);
-               mas_dup_state(&cp, mas);
+       mas_dup_state(&cp, mas);
 
-               if (slot)
-                       prev_piv = mte_get_pivot(mas->node, slot - 1);
-
-               if (active) {
-                       cp.node = mt_mk_node(ma_mnode_ptr(mas_next_alloc(mas)),
-                                       mas_type);
-                       mn = mas_mn(mas);
-               } else {
-                       // Note cp.node == mas->node here.
-                       mn = &space;
-                       memcpy(mn, mas_mn(mas), sizeof(struct maple_node));
-                       memset(mas_mn(&cp), 0, sizeof(struct maple_node));
-               }
-               mas_mn(&cp)->parent = mn->parent;
-               if (prev_piv == mas->index - 1) {
-                       if (slot) // slot - 1 will translate to slot - 1 + 1.
-                               end_slot = _mas_append(&cp, mn, mas_type,
-                                               src_max, 0, slot - 1);
-               } else {
-                       end_slot = _mas_append(&cp, mn, mas_type, src_max, 0, slot);
-                       if (end_slot < mt_pivot_count(cp.node))
-                               mte_set_pivot(cp.node, end_slot, mas->index - 1);
-               }
+       if (slot)
+               prev_piv = mte_get_pivot(mas->node, slot - 1);
 
-               mas_set_slot(&cp, end_slot);
-               end_slot = mas_append_entry(&cp, entry) + 1;
+       if (active) {
+               cp.node = mt_mk_node(ma_mnode_ptr(mas_next_alloc(mas)),
+                               mas_type);
+               mn = mas_mn(mas);
+       } else {
+               // Note cp.node == mas->node here.
+               mn = &space;
+               memcpy(mn, mas_mn(mas), sizeof(struct maple_node));
+               memset(mas_mn(&cp), 0, sizeof(struct maple_node));
+       }
+       mas_mn(&cp)->parent = mn->parent;
+       if (prev_piv == mas->index - 1) {
+               if (slot) // slot - 1 will translate to slot - 1 + 1.
+                       end_slot = _mas_append(&cp, mn, mas_type, src_max, 0,
+                                       slot - 1);
+       } else {
+               end_slot = _mas_append(&cp, mn, mas_type, src_max, 0, slot);
+               if (end_slot < mt_pivot_count(cp.node))
+                       mte_set_pivot(cp.node, end_slot, mas->index - 1);
+       }
 
-               // Partial slot overwrite
-               slot = mas_skip_overwritten(mas, data_end, slot);
-               if (slot >= mt_slot_count(mas->node))
-                       goto done; // potential spanning add.
+       mas_set_slot(&cp, end_slot);
+       end_slot = mas_append_entry(&cp, entry) + 1;
 
-               mas_get_range(mas, slot, &prev_piv, &piv);
+       // Partial slot overwrite
+       slot = mas_skip_overwritten(mas, data_end, slot);
+       if (slot >= mt_slot_count(mas->node))
+               goto done; // potential spanning add.
 
-               existing_entry = mas_get_rcu_sanitized(mas, slot);
-               if (prev_piv <= mas->last && piv > mas->last) {
-                       mte_set_rcu_slot(cp.node, end_slot, existing_entry);
-                       mas_set_safe_pivot(&cp, end_slot++, piv);
-                       cp.max = piv;
-                       slot++;
-               }
+       mas_get_range(mas, slot, &prev_piv, &piv);
+       existing_entry = mas_get_rcu_sanitized(mas, slot);
+       if (prev_piv <= mas->last && piv > mas->last) {
+               mte_set_rcu_slot(cp.node, end_slot, existing_entry);
+               mas_set_safe_pivot(&cp, end_slot++, piv);
+               cp.max = piv;
+               slot++;
+       }
+       if (slot <= data_end && cp.max < mas->max)
+               _mas_append(&cp, mn, mas_type, src_max, slot, data_end);
 
-               if (slot <= data_end && cp.max < mas->max) {
-                       _mas_append(&cp, mn, mas_type, src_max, slot,
-                                       data_end);
-               }
 done:
-               if (active)
-                       mas->node = cp.node;
-
-       }
+       if (active)
+               mas->node = cp.node;
 
        return ret;
 }
@@ -2525,6 +2635,7 @@ static inline int _mas_add(struct ma_state *mas, void *entry, bool overwrite,
                                active);
                if (!ret)
                        return ret;
+               old_end = 0; // fixme.
                goto update_gap;
        }
 
@@ -2611,8 +2722,11 @@ complete:
                ret = mas_spanning_add(mas, entry, spans_node);
 
 update_gap:
-       if (mt_is_alloc(mas->tree))
+       if (mt_is_alloc(mas->tree)) {
                mas_update_gap(mas, false);
+               if (!entry && (slot >= old_end || !slot))
+                       mas_may_move_gap(mas);
+       }
 
        return ret;
 }
@@ -3599,7 +3713,6 @@ static inline bool _mas_rev_awalk(struct ma_state *mas, unsigned long size)
        switch (type) {
        case maple_leaf_64:
                start = i;
-
                do {
                        void *entry = NULL;
 
@@ -4752,6 +4865,7 @@ static inline void *mas_erase(struct ma_state *mas)
        // dense nodes only need to set a single value.
 
        mas_rebalance(mas);
+       mas_may_move_gap(mas);
        return entry;
 }
 

diff --git a/lib/test_maple_tree.c b/lib/test_maple_tree.c
index 695cd392acbc5baaef59721f76615ebd4a257087..8352a04e8c41c217fc7aa4db9f7437038ffc959c 100644 (file)
--- a/lib/test_maple_tree.c
+++ b/lib/test_maple_tree.c
@@ -10601,521 +10601,6 @@ STORE, 140656836775936, 140656836780031,
 STORE, 140656787476480, 140656791920639,
 ERASE, 140656774639616, 140656779083775,
        };
-       unsigned long set20[] = {
-STORE, 140737488347136, 140737488351231,
-STORE, 140733986955264, 140737488351231,
-SNULL, 140733986959359, 140737488351231,
-STORE, 140733986955264, 140733986959359,
-STORE, 140733986824192, 140733986959359,
-STORE, 94410716639232, 94410717106175,
-SNULL, 94410717057023, 94410717106175,
-STORE, 94410716639232, 94410717057023,
-STORE, 94410717057024, 94410717106175,
-ERASE, 94410717057024, 94410717106175,
-STORE, 94410717057024, 94410717106175,
-STORE, 140557326688256, 140557328941055,
-SNULL, 140557326831615, 140557328941055,
-STORE, 140557326688256, 140557326831615,
-STORE, 140557326831616, 140557328941055,
-ERASE, 140557326831616, 140557328941055,
-STORE, 140557328928768, 140557328936959,
-STORE, 140557328936960, 140557328941055,
-STORE, 140733987811328, 140733987815423,
-STORE, 140733987799040, 140733987811327,
-STORE, 140557328924672, 140557328928767,
-STORE, 140557328916480, 140557328924671,
-STORE, 140557324554240, 140557326688255,
-SNULL, 140557324554240, 140557324582911,
-STORE, 140557324582912, 140557326688255,
-STORE, 140557324554240, 140557324582911,
-SNULL, 140557326680063, 140557326688255,
-STORE, 140557324582912, 140557326680063,
-STORE, 140557326680064, 140557326688255,
-ERASE, 140557326680064, 140557326688255,
-STORE, 140557326680064, 140557326688255,
-STORE, 140557322170368, 140557324554239,
-SNULL, 140557322170368, 140557322436607,
-STORE, 140557322436608, 140557324554239,
-STORE, 140557322170368, 140557322436607,
-SNULL, 140557324529663, 140557324554239,
-STORE, 140557322436608, 140557324529663,
-STORE, 140557324529664, 140557324554239,
-SNULL, 140557324529664, 140557324550143,
-STORE, 140557324550144, 140557324554239,
-STORE, 140557324529664, 140557324550143,
-ERASE, 140557324529664, 140557324550143,
-STORE, 140557324529664, 140557324550143,
-ERASE, 140557324550144, 140557324554239,
-STORE, 140557324550144, 140557324554239,
-STORE, 140557319979008, 140557322170367,
-SNULL, 140557319979008, 140557320069119,
-STORE, 140557320069120, 140557322170367,
-STORE, 140557319979008, 140557320069119,
-SNULL, 140557322162175, 140557322170367,
-STORE, 140557320069120, 140557322162175,
-STORE, 140557322162176, 140557322170367,
-ERASE, 140557322162176, 140557322170367,
-STORE, 140557322162176, 140557322170367,
-STORE, 140557317718016, 140557319979007,
-SNULL, 140557317718016, 140557317869567,
-STORE, 140557317869568, 140557319979007,
-STORE, 140557317718016, 140557317869567,
-SNULL, 140557319962623, 140557319979007,
-STORE, 140557317869568, 140557319962623,
-STORE, 140557319962624, 140557319979007,
-SNULL, 140557319962624, 140557319970815,
-STORE, 140557319970816, 140557319979007,
-STORE, 140557319962624, 140557319970815,
-ERASE, 140557319962624, 140557319970815,
-STORE, 140557319962624, 140557319970815,
-ERASE, 140557319970816, 140557319979007,
-STORE, 140557319970816, 140557319979007,
-STORE, 140557315588096, 140557317718015,
-SNULL, 140557315588096, 140557315616767,
-STORE, 140557315616768, 140557317718015,
-STORE, 140557315588096, 140557315616767,
-SNULL, 140557317709823, 140557317718015,
-STORE, 140557315616768, 140557317709823,
-STORE, 140557317709824, 140557317718015,
-ERASE, 140557317709824, 140557317718015,
-STORE, 140557317709824, 140557317718015,
-STORE, 140557313372160, 140557315588095,
-SNULL, 140557313372160, 140557313470463,
-STORE, 140557313470464, 140557315588095,
-STORE, 140557313372160, 140557313470463,
-SNULL, 140557315563519, 140557315588095,
-STORE, 140557313470464, 140557315563519,
-STORE, 140557315563520, 140557315588095,
-SNULL, 140557315563520, 140557315571711,
-STORE, 140557315571712, 140557315588095,
-STORE, 140557315563520, 140557315571711,
-ERASE, 140557315563520, 140557315571711,
-STORE, 140557315563520, 140557315571711,
-ERASE, 140557315571712, 140557315588095,
-STORE, 140557315571712, 140557315588095,
-STORE, 140557328908288, 140557328924671,
-STORE, 140557309575168, 140557313372159,
-SNULL, 140557309575168, 140557311234047,
-STORE, 140557311234048, 140557313372159,
-STORE, 140557309575168, 140557311234047,
-SNULL, 140557313331199, 140557313372159,
-STORE, 140557311234048, 140557313331199,
-STORE, 140557313331200, 140557313372159,
-SNULL, 140557313331200, 140557313355775,
-STORE, 140557313355776, 140557313372159,
-STORE, 140557313331200, 140557313355775,
-ERASE, 140557313331200, 140557313355775,
-STORE, 140557313331200, 140557313355775,
-ERASE, 140557313355776, 140557313372159,
-STORE, 140557313355776, 140557313372159,
-STORE, 140557307457536, 140557309575167,
-SNULL, 140557307457536, 140557307473919,
-STORE, 140557307473920, 140557309575167,
-STORE, 140557307457536, 140557307473919,
-SNULL, 140557309566975, 140557309575167,
-STORE, 140557307473920, 140557309566975,
-STORE, 140557309566976, 140557309575167,
-ERASE, 140557309566976, 140557309575167,
-STORE, 140557309566976, 140557309575167,
-STORE, 140557305339904, 140557307457535,
-SNULL, 140557305339904, 140557305356287,
-STORE, 140557305356288, 140557307457535,
-STORE, 140557305339904, 140557305356287,
-SNULL, 140557307449343, 140557307457535,
-STORE, 140557305356288, 140557307449343,
-STORE, 140557307449344, 140557307457535,
-ERASE, 140557307449344, 140557307457535,
-STORE, 140557307449344, 140557307457535,
-STORE, 140557302771712, 140557305339903,
-SNULL, 140557302771712, 140557303238655,
-STORE, 140557303238656, 140557305339903,
-STORE, 140557302771712, 140557303238655,
-SNULL, 140557305331711, 140557305339903,
-STORE, 140557303238656, 140557305331711,
-STORE, 140557305331712, 140557305339903,
-ERASE, 140557305331712, 140557305339903,
-STORE, 140557305331712, 140557305339903,
-STORE, 140557300658176, 140557302771711,
-SNULL, 140557300658176, 140557300670463,
-STORE, 140557300670464, 140557302771711,
-STORE, 140557300658176, 140557300670463,
-SNULL, 140557302763519, 140557302771711,
-STORE, 140557300670464, 140557302763519,
-STORE, 140557302763520, 140557302771711,
-ERASE, 140557302763520, 140557302771711,
-STORE, 140557302763520, 140557302771711,
-STORE, 140557328900096, 140557328924671,
-STORE, 140557328887808, 140557328924671,
-SNULL, 140557313347583, 140557313355775,
-STORE, 140557313331200, 140557313347583,
-STORE, 140557313347584, 140557313355775,
-SNULL, 140557302767615, 140557302771711,
-STORE, 140557302763520, 140557302767615,
-STORE, 140557302767616, 140557302771711,
-SNULL, 140557315567615, 140557315571711,
-STORE, 140557315563520, 140557315567615,
-STORE, 140557315567616, 140557315571711,
-SNULL, 140557305335807, 140557305339903,
-STORE, 140557305331712, 140557305335807,
-STORE, 140557305335808, 140557305339903,
-SNULL, 140557307453439, 140557307457535,
-STORE, 140557307449344, 140557307453439,
-STORE, 140557307453440, 140557307457535,
-SNULL, 140557309571071, 140557309575167,
-STORE, 140557309566976, 140557309571071,
-STORE, 140557309571072, 140557309575167,
-SNULL, 140557317713919, 140557317718015,
-STORE, 140557317709824, 140557317713919,
-STORE, 140557317713920, 140557317718015,
-SNULL, 140557319966719, 140557319970815,
-STORE, 140557319962624, 140557319966719,
-STORE, 140557319966720, 140557319970815,
-SNULL, 140557322166271, 140557322170367,
-STORE, 140557322162176, 140557322166271,
-STORE, 140557322166272, 140557322170367,
-SNULL, 140557324546047, 140557324550143,
-STORE, 140557324529664, 140557324546047,
-STORE, 140557324546048, 140557324550143,
-SNULL, 140557326684159, 140557326688255,
-STORE, 140557326680064, 140557326684159,
-STORE, 140557326684160, 140557326688255,
-SNULL, 94410717102079, 94410717106175,
-STORE, 94410717057024, 94410717102079,
-STORE, 94410717102080, 94410717106175,
-SNULL, 140557328932863, 140557328936959,
-STORE, 140557328928768, 140557328932863,
-STORE, 140557328932864, 140557328936959,
-ERASE, 140557328924672, 140557328928767,
-STORE, 94410726526976, 94410726662143,
-STORE, 140737488347136, 140737488351231,
-STORE, 140727481659392, 140737488351231,
-SNULL, 140727481663487, 140737488351231,
-STORE, 140727481659392, 140727481663487,
-STORE, 140727481528320, 140727481663487,
-STORE, 94301767393280, 94301769547775,
-SNULL, 94301767446527, 94301769547775,
-STORE, 94301767393280, 94301767446527,
-STORE, 94301767446528, 94301769547775,
-ERASE, 94301767446528, 94301769547775,
-STORE, 94301769539584, 94301769547775,
-STORE, 140365555687424, 140365557940223,
-SNULL, 140365555830783, 140365557940223,
-STORE, 140365555687424, 140365555830783,
-STORE, 140365555830784, 140365557940223,
-ERASE, 140365555830784, 140365557940223,
-STORE, 140365557927936, 140365557936127,
-STORE, 140365557936128, 140365557940223,
-STORE, 140727482724352, 140727482728447,
-STORE, 140727482712064, 140727482724351,
-STORE, 140365557903360, 140365557927935,
-STORE, 140365557895168, 140365557903359,
-STORE, 140365551890432, 140365555687423,
-SNULL, 140365551890432, 140365553549311,
-STORE, 140365553549312, 140365555687423,
-STORE, 140365551890432, 140365553549311,
-SNULL, 140365555646463, 140365555687423,
-STORE, 140365553549312, 140365555646463,
-STORE, 140365555646464, 140365555687423,
-SNULL, 140365555646464, 140365555671039,
-STORE, 140365555671040, 140365555687423,
-STORE, 140365555646464, 140365555671039,
-ERASE, 140365555646464, 140365555671039,
-STORE, 140365555646464, 140365555671039,
-ERASE, 140365555671040, 140365555687423,
-STORE, 140365555671040, 140365555687423,
-SNULL, 140365555662847, 140365555671039,
-STORE, 140365555646464, 140365555662847,
-STORE, 140365555662848, 140365555671039,
-SNULL, 94301769543679, 94301769547775,
-STORE, 94301769539584, 94301769543679,
-STORE, 94301769543680, 94301769547775,
-SNULL, 140365557932031, 140365557936127,
-STORE, 140365557927936, 140365557932031,
-STORE, 140365557932032, 140365557936127,
-ERASE, 140365557903360, 140365557927935,
-STORE, 94301792006144, 94301792141311,
-STORE, 140737488347136, 140737488351231,
-STORE, 140734780747776, 140737488351231,
-SNULL, 140734780751871, 140737488351231,
-STORE, 140734780747776, 140734780751871,
-STORE, 140734780616704, 140734780751871,
-STORE, 94557838819328, 94557841571839,
-SNULL, 94557839429631, 94557841571839,
-STORE, 94557838819328, 94557839429631,
-STORE, 94557839429632, 94557841571839,
-ERASE, 94557839429632, 94557841571839,
-STORE, 94557841526784, 94557841567743,
-STORE, 94557841567744, 94557841571839,
-STORE, 140503043223552, 140503045476351,
-SNULL, 140503043366911, 140503045476351,
-STORE, 140503043223552, 140503043366911,
-STORE, 140503043366912, 140503045476351,
-ERASE, 140503043366912, 140503045476351,
-STORE, 140503045464064, 140503045472255,
-STORE, 140503045472256, 140503045476351,
-STORE, 140734780923904, 140734780927999,
-STORE, 140734780911616, 140734780923903,
-STORE, 140503045439488, 140503045464063,
-STORE, 140503045431296, 140503045439487,
-STORE, 140503041019904, 140503043223551,
-SNULL, 140503041019904, 140503041122303,
-STORE, 140503041122304, 140503043223551,
-STORE, 140503041019904, 140503041122303,
-SNULL, 140503043215359, 140503043223551,
-STORE, 140503041122304, 140503043215359,
-STORE, 140503043215360, 140503043223551,
-ERASE, 140503043215360, 140503043223551,
-STORE, 140503043215360, 140503043223551,
-STORE, 140503038803968, 140503041019903,
-SNULL, 140503038803968, 140503038902271,
-STORE, 140503038902272, 140503041019903,
-STORE, 140503038803968, 140503038902271,
-SNULL, 140503040995327, 140503041019903,
-STORE, 140503038902272, 140503040995327,
-STORE, 140503040995328, 140503041019903,
-SNULL, 140503040995328, 140503041003519,
-STORE, 140503041003520, 140503041019903,
-STORE, 140503040995328, 140503041003519,
-ERASE, 140503040995328, 140503041003519,
-STORE, 140503040995328, 140503041003519,
-ERASE, 140503041003520, 140503041019903,
-STORE, 140503041003520, 140503041019903,
-STORE, 140503036690432, 140503038803967,
-SNULL, 140503036690432, 140503036702719,
-STORE, 140503036702720, 140503038803967,
-STORE, 140503036690432, 140503036702719,
-SNULL, 140503038795775, 140503038803967,
-STORE, 140503036702720, 140503038795775,
-STORE, 140503038795776, 140503038803967,
-ERASE, 140503038795776, 140503038803967,
-STORE, 140503038795776, 140503038803967,
-STORE, 140503034560512, 140503036690431,
-SNULL, 140503034560512, 140503034589183,
-STORE, 140503034589184, 140503036690431,
-STORE, 140503034560512, 140503034589183,
-SNULL, 140503036682239, 140503036690431,
-STORE, 140503034589184, 140503036682239,
-STORE, 140503036682240, 140503036690431,
-ERASE, 140503036682240, 140503036690431,
-STORE, 140503036682240, 140503036690431,
-STORE, 140503032446976, 140503034560511,
-SNULL, 140503032446976, 140503032459263,
-STORE, 140503032459264, 140503034560511,
-STORE, 140503032446976, 140503032459263,
-SNULL, 140503034552319, 140503034560511,
-STORE, 140503032459264, 140503034552319,
-STORE, 140503034552320, 140503034560511,
-ERASE, 140503034552320, 140503034560511,
-STORE, 140503034552320, 140503034560511,
-STORE, 140503030308864, 140503032446975,
-SNULL, 140503030308864, 140503030345727,
-STORE, 140503030345728, 140503032446975,
-STORE, 140503030308864, 140503030345727,
-SNULL, 140503032438783, 140503032446975,
-STORE, 140503030345728, 140503032438783,
-STORE, 140503032438784, 140503032446975,
-ERASE, 140503032438784, 140503032446975,
-STORE, 140503032438784, 140503032446975,
-STORE, 140503045423104, 140503045439487,
-STORE, 140503028191232, 140503030308863,
-SNULL, 140503028191232, 140503028207615,
-STORE, 140503028207616, 140503030308863,
-STORE, 140503028191232, 140503028207615,
-SNULL, 140503030300671, 140503030308863,
-STORE, 140503028207616, 140503030300671,
-STORE, 140503030300672, 140503030308863,
-ERASE, 140503030300672, 140503030308863,
-STORE, 140503030300672, 140503030308863,
-STORE, 140503026073600, 140503028191231,
-SNULL, 140503026073600, 140503026089983,
-STORE, 140503026089984, 140503028191231,
-STORE, 140503026073600, 140503026089983,
-SNULL, 140503028183039, 140503028191231,
-STORE, 140503026089984, 140503028183039,
-STORE, 140503028183040, 140503028191231,
-ERASE, 140503028183040, 140503028191231,
-STORE, 140503028183040, 140503028191231,
-STORE, 140503022276608, 140503026073599,
-SNULL, 140503022276608, 140503023935487,
-STORE, 140503023935488, 140503026073599,
-STORE, 140503022276608, 140503023935487,
-SNULL, 140503026032639, 140503026073599,
-STORE, 140503023935488, 140503026032639,
-STORE, 140503026032640, 140503026073599,
-SNULL, 140503026032640, 140503026057215,
-STORE, 140503026057216, 140503026073599,
-STORE, 140503026032640, 140503026057215,
-ERASE, 140503026032640, 140503026057215,
-STORE, 140503026032640, 140503026057215,
-ERASE, 140503026057216, 140503026073599,
-STORE, 140503026057216, 140503026073599,
-STORE, 140503045414912, 140503045439487,
-SNULL, 140503026049023, 140503026057215,
-STORE, 140503026032640, 140503026049023,
-STORE, 140503026049024, 140503026057215,
-SNULL, 140503028187135, 140503028191231,
-STORE, 140503028183040, 140503028187135,
-STORE, 140503028187136, 140503028191231,
-SNULL, 140503030304767, 140503030308863,
-STORE, 140503030300672, 140503030304767,
-STORE, 140503030304768, 140503030308863,
-SNULL, 140503032442879, 140503032446975,
-STORE, 140503032438784, 140503032442879,
-STORE, 140503032442880, 140503032446975,
-SNULL, 140503034556415, 140503034560511,
-STORE, 140503034552320, 140503034556415,
-STORE, 140503034556416, 140503034560511,
-SNULL, 140503040999423, 140503041003519,
-STORE, 140503040995328, 140503040999423,
-STORE, 140503040999424, 140503041003519,
-SNULL, 140503036686335, 140503036690431,
-STORE, 140503036682240, 140503036686335,
-STORE, 140503036686336, 140503036690431,
-SNULL, 140503038799871, 140503038803967,
-STORE, 140503038795776, 140503038799871,
-STORE, 140503038799872, 140503038803967,
-SNULL, 140503043219455, 140503043223551,
-STORE, 140503043215360, 140503043219455,
-STORE, 140503043219456, 140503043223551,
-SNULL, 94557841539071, 94557841567743,
-STORE, 94557841526784, 94557841539071,
-STORE, 94557841539072, 94557841567743,
-SNULL, 140503045468159, 140503045472255,
-STORE, 140503045464064, 140503045468159,
-STORE, 140503045468160, 140503045472255,
-ERASE, 140503045439488, 140503045464063,
-STORE, 94557855555584, 94557855694847,
-STORE, 140503020154880, 140503022276607,
-SNULL, 140503020154880, 140503020175359,
-STORE, 140503020175360, 140503022276607,
-STORE, 140503020154880, 140503020175359,
-SNULL, 140503022268415, 140503022276607,
-STORE, 140503020175360, 140503022268415,
-STORE, 140503022268416, 140503022276607,
-ERASE, 140503022268416, 140503022276607,
-STORE, 140503022268416, 140503022276607,
-SNULL, 140503022272511, 140503022276607,
-STORE, 140503022268416, 140503022272511,
-STORE, 140503022272512, 140503022276607,
-STORE, 140503045439488, 140503045464063,
-STORE, 140503017984000, 140503020154879,
-SNULL, 140503017984000, 140503018024959,
-STORE, 140503018024960, 140503020154879,
-STORE, 140503017984000, 140503018024959,
-SNULL, 140503020122111, 140503020154879,
-STORE, 140503018024960, 140503020122111,
-STORE, 140503020122112, 140503020154879,
-SNULL, 140503020122112, 140503020130303,
-STORE, 140503020130304, 140503020154879,
-STORE, 140503020122112, 140503020130303,
-ERASE, 140503020122112, 140503020130303,
-STORE, 140503020122112, 140503020130303,
-ERASE, 140503020130304, 140503020154879,
-STORE, 140503020130304, 140503020154879,
-SNULL, 140503020126207, 140503020130303,
-STORE, 140503020122112, 140503020126207,
-STORE, 140503020126208, 140503020130303,
-ERASE, 140503045439488, 140503045464063,
-STORE, 140503015854080, 140503017983999,
-SNULL, 140503015854080, 140503015882751,
-STORE, 140503015882752, 140503017983999,
-STORE, 140503015854080, 140503015882751,
-SNULL, 140503017975807, 140503017983999,
-STORE, 140503015882752, 140503017975807,
-STORE, 140503017975808, 140503017983999,
-ERASE, 140503017975808, 140503017983999,
-STORE, 140503017975808, 140503017983999,
-SNULL, 140503017979903, 140503017983999,
-STORE, 140503017975808, 140503017979903,
-STORE, 140503017979904, 140503017983999,
-STORE, 140503013736448, 140503015854079,
-SNULL, 140503013736448, 140503013752831,
-STORE, 140503013752832, 140503015854079,
-STORE, 140503013736448, 140503013752831,
-SNULL, 140503015845887, 140503015854079,
-STORE, 140503013752832, 140503015845887,
-STORE, 140503015845888, 140503015854079,
-ERASE, 140503015845888, 140503015854079,
-STORE, 140503015845888, 140503015854079,
-SNULL, 140503015849983, 140503015854079,
-STORE, 140503015845888, 140503015849983,
-STORE, 140503015849984, 140503015854079,
-STORE, 140503045439488, 140503045464063,
-STORE, 140503011606528, 140503013736447,
-SNULL, 140503011606528, 140503011635199,
-STORE, 140503011635200, 140503013736447,
-STORE, 140503011606528, 140503011635199,
-SNULL, 140503013728255, 140503013736447,
-STORE, 140503011635200, 140503013728255,
-STORE, 140503013728256, 140503013736447,
-ERASE, 140503013728256, 140503013736447,
-STORE, 140503013728256, 140503013736447,
-STORE, 140503009411072, 140503011606527,
-SNULL, 140503009411072, 140503009492991,
-STORE, 140503009492992, 140503011606527,
-STORE, 140503009411072, 140503009492991,
-SNULL, 140503011590143, 140503011606527,
-STORE, 140503009492992, 140503011590143,
-STORE, 140503011590144, 140503011606527,
-SNULL, 140503011590144, 140503011598335,
-STORE, 140503011598336, 140503011606527,
-STORE, 140503011590144, 140503011598335,
-ERASE, 140503011590144, 140503011598335,
-STORE, 140503011590144, 140503011598335,
-ERASE, 140503011598336, 140503011606527,
-STORE, 140503011598336, 140503011606527,
-SNULL, 140503011594239, 140503011598335,
-STORE, 140503011590144, 140503011594239,
-STORE, 140503011594240, 140503011598335,
-SNULL, 140503013732351, 140503013736447,
-STORE, 140503013728256, 140503013732351,
-STORE, 140503013732352, 140503013736447,
-ERASE, 140503045439488, 140503045464063,
-STORE, 140503045439488, 140503045464063,
-STORE, 140503007264768, 140503009411071,
-SNULL, 140503007264768, 140503007309823,
-STORE, 140503007309824, 140503009411071,
-STORE, 140503007264768, 140503007309823,
-SNULL, 140503009402879, 140503009411071,
-STORE, 140503007309824, 140503009402879,
-STORE, 140503009402880, 140503009411071,
-ERASE, 140503009402880, 140503009411071,
-STORE, 140503009402880, 140503009411071,
-SNULL, 140503009406975, 140503009411071,
-STORE, 140503009402880, 140503009406975,
-STORE, 140503009406976, 140503009411071,
-ERASE, 140503045439488, 140503045464063,
-STORE, 140503045459968, 140503045464063,
-ERASE, 140503045459968, 140503045464063,
-STORE, 140503045459968, 140503045464063,
-ERASE, 140503045459968, 140503045464063,
-STORE, 94557855555584, 94557855838207,
-SNULL, 94557855805439, 94557855838207,
-STORE, 94557855555584, 94557855805439,
-STORE, 94557855805440, 94557855838207,
-ERASE, 94557855805440, 94557855838207,
-STORE, 140503044612096, 140503045439487,
-STORE, 140503003066368, 140503007264767,
-SNULL, 140503003070463, 140503007264767,
-STORE, 140503003066368, 140503003070463,
-STORE, 140503003070464, 140503007264767,
-STORE, 140502998867968, 140503003066367,
-STORE, 140502864650240, 140502998867967,
-SNULL, 140502864650240, 140502875766783,
-STORE, 140502875766784, 140502998867967,
-STORE, 140502864650240, 140502875766783,
-ERASE, 140502864650240, 140502875766783,
-SNULL, 140502998872063, 140503003066367,
-STORE, 140502998867968, 140502998872063,
-STORE, 140502998872064, 140503003066367,
-SNULL, 140502942875647, 140502998867967,
-STORE, 140502875766784, 140502942875647,
-STORE, 140502942875648, 140502998867967,
-ERASE, 140502942875648, 140502998867967,
-SNULL, 140502875910143, 140502942875647,
-STORE, 140502875766784, 140502875910143,
-STORE, 140502875910144, 140502942875647,
-       };
 
        int cnt = 0;
        MA_STATE(mas, mt, 0, 0);
@@ -11271,19 +10756,6 @@ STORE, 140502875910144, 140502942875647,
        entry = mas_prev(&mas, 0);
        MT_BUG_ON(mt, entry != xa_mk_value(140656766251008));
        mtree_destroy(mt);
-
-       /* set20 found a bug in an add that spanned the node boundaries but
-        * sill required the node to be split.
-        */
-       mt_set_non_kernel(99);
-       mas_reset(&mas);
-       mtree_init(mt, MAPLE_ALLOC_RANGE);
-       check_erase2_testset(mt, set20, ARRAY_SIZE(set20));
-       rcu_barrier();
-       mas_get_unmapped_area_rev(&mas, 4096, 140503045476352, 134217728);
-       MT_BUG_ON(mt, mas.index != 140502741549056);
-       mtree_destroy(mt);
-
 }
 
 static noinline void check_alloc_rev_range(struct maple_tree *mt)
@@ -11687,6 +11159,85 @@ static noinline void check_prev_entry(struct maple_tree *mt)
        mtree_destroy(mt);
 
 }
+static noinline void check_gap_combining(struct maple_tree *mt)
+{
+       struct maple_enode *mn1, *mn2;
+       void *entry;
+       unsigned long index = 86;
+
+       MA_STATE(mas, mt, index, index);
+
+       MT_BUG_ON(mt, !mtree_empty(mt));
+       check_seq(mt, 100, false); // create 100 singletons.
+
+       mtree_test_erase(mt, 88);
+       mtree_test_erase(mt, 87);
+
+       rcu_read_lock();
+       entry = mas_find(&mas, ULONG_MAX);
+       MT_BUG_ON(mt, entry != xa_mk_value(index));
+       mn1 = mas.node;
+       entry = mas_next(&mas, ULONG_MAX);
+       MT_BUG_ON(mt, entry != xa_mk_value(index + 3));
+       mn2 = mas.node;
+       MT_BUG_ON(mt, mn1 == mn2);
+
+       // At this point, there is a gap of 2 in either 1 or 2 nodes.  Find a
+       // gap of size 2 from 100 down to 50.
+       mas_reset(&mas);
+       MT_BUG_ON(mt, mas_get_unmapped_area_rev(&mas, 50, 100, 2));
+       MT_BUG_ON(mt, mas.index != 87);
+       rcu_read_unlock();
+
+       mtree_test_erase(mt, 38);
+       mtree_test_erase(mt, 39);
+       mtree_test_erase(mt, 40);
+       index = 37;
+
+       rcu_read_lock();
+       mas.index = index;
+       mas.last = index;
+       mas_reset(&mas);
+       entry = mas_find(&mas, ULONG_MAX);
+       MT_BUG_ON(mt, entry != xa_mk_value(index));
+       mn1 = mas.node;
+       entry = mas_next(&mas, ULONG_MAX);
+       MT_BUG_ON(mt, entry != xa_mk_value(index + 4));
+       mn2 = mas.node;
+       MT_BUG_ON(mt, mn1 == mn2);
+
+       // At this point, there is a gap of 2 in either 1 or 2 nodes.  Find a
+       // gap of size 2 from 100 down to 50.
+       mas_reset(&mas);
+       MT_BUG_ON(mt, mas_get_unmapped_area_rev(&mas, 20, 50, 3));
+       MT_BUG_ON(mt, mas.index != 38);
+       rcu_read_unlock();
+
+       mtree_store(mt, 79, NULL, GFP_KERNEL);
+       mtree_store(mt, 80, NULL, GFP_KERNEL);
+
+       mas_reset(&mas);
+       rcu_read_lock();
+       MT_BUG_ON(mt, mas_get_unmapped_area_rev(&mas, 76, 81, 2));
+       MT_BUG_ON(mt, mas.index != 79);
+       rcu_read_unlock();
+
+       mtree_destroy(mt);
+       mtree_init(mt, MAPLE_ALLOC_RANGE);
+       check_seq(mt, 2000, false);
+       mtree_test_erase(mt, 1792);
+       mtree_test_erase(mt, 1791);
+
+       mas_reset(&mas);
+       rcu_read_lock();
+       MT_BUG_ON(mt, mas_get_unmapped_area_rev(&mas, 1700, 1800, 2));
+       MT_BUG_ON(mt, mas.index != 1791);
+       rcu_read_unlock();
+       mtree_destroy(mt);
+
+}
+
+
 static DEFINE_MTREE(tree);
 
 static int maple_tree_seed(void)
@@ -11848,10 +11399,14 @@ static int maple_tree_seed(void)
        mtree_init(&tree, 0);
        check_erase2_sets(&tree);
        mtree_destroy(&tree);
-       rcu_barrier();
 
+       mtree_init(&tree, MAPLE_ALLOC_RANGE);
+       check_gap_combining(&tree);
+       mtree_destroy(&tree);
+
+       rcu_barrier();
        pr_info("maple_tree: %u of %u tests passed\n", maple_tree_tests_passed,
-               maple_tree_tests_run);
+                       maple_tree_tests_run);
        return (maple_tree_tests_run == maple_tree_tests_passed) ? 0 : -EINVAL;
 }