FIXME maple_tree reduce ascending by tracking parent

rebalance change is more..

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

diff --git a/lib/maple_tree.c b/lib/maple_tree.c
index f7c2806f0f0743b5426eaf5261cea9f0a316231d..b2300c798feac067ae576f2d7b0a0f0f62c2dc31 100644 (file)
--- a/lib/maple_tree.c
+++ b/lib/maple_tree.c
@@ -1931,15 +1931,11 @@ static inline void mas_wr_node_walk(struct ma_wr_state *wr_mas)
        wr_mas->offset_end = mas->offset = offset;
 }
 
-static inline void rebalance_sib(struct ma_state *mas, struct ma_state *sib)
+static inline void rebalance_sib(struct ma_state *parent, struct ma_state *sib)
 {
-       unsigned char end;
-
-       *sib = *mas;
-       mas_ascend(sib);
-       end = mas_data_end(sib);
+       *sib = *parent;
        /* Prioritize move right to pull data left */
-       if (sib->offset < end)
+       if (sib->offset < sib->end)
                sib->offset++;
        else
                sib->offset--;
@@ -2478,15 +2474,15 @@ static bool data_fits(struct ma_state *sib, struct ma_state *mas,
        return false;
 }
 
-static void push_data_sib(struct maple_copy *cp, struct ma_state *mas,
-               struct ma_state *sib)
+static inline void push_data_sib(struct maple_copy *cp, struct ma_state *mas,
+               struct ma_state *sib, struct ma_state *parent)
 {
+
        if (mte_is_root(mas->node))
                goto no_push;
 
 
-       *sib = *mas;
-       mas_ascend(sib);
+       *sib = *parent;
        if (sib->offset) {
                sib->offset--;
                mas_descend(sib);
@@ -2494,11 +2490,9 @@ static void push_data_sib(struct maple_copy *cp, struct ma_state *mas,
                if (data_fits(sib, mas, cp))    /* Push left */
                        return;
 
-               mas_ascend(sib);
-               sib->offset++;
+               *sib = *parent;
        }
 
-       sib->end = mas_data_end(sib);
        if (sib->offset >= sib->end)
                goto no_push;
 
@@ -2524,20 +2518,21 @@ no_push:
  *
  */
 static inline void rebalance_data(struct maple_copy *cp,
-               struct ma_wr_state *wr_mas, struct ma_state *sib)
+               struct ma_wr_state *wr_mas, struct ma_state *sib,
+               struct ma_state *parent)
 {
        cp_data_calc(cp, wr_mas, wr_mas);
        sib->end = 0;
        if (cp->data >= mt_slots[wr_mas->type]) {
-               push_data_sib(cp, wr_mas->mas, sib);
+               push_data_sib(cp, wr_mas->mas, sib, parent);
                if (sib->end)
                        goto use_sib;
-       }
-
-       if (((wr_mas->mas->min != 0) || (wr_mas->mas->max != ULONG_MAX)) &&
-           (cp->data <= mt_min_slots[wr_mas->type])) {
-               rebalance_sib(wr_mas->mas, sib);
-               goto use_sib;
+       } else if (cp->data <= mt_min_slots[wr_mas->type]) {
+               if ((wr_mas->mas->min != 0) ||
+                   (wr_mas->mas->max != ULONG_MAX)) {
+                       rebalance_sib(parent, sib);
+                       goto use_sib;
+               }
        }
 
        return;
@@ -2912,7 +2907,8 @@ static bool spanning_ascend(struct maple_copy *cp, struct ma_state *mas,
  * needed, false otherwise.
  */
 static inline bool rebalance_ascend(struct maple_copy *cp,
-               struct ma_wr_state *wr_mas, struct ma_state *sib)
+               struct ma_wr_state *wr_mas, struct ma_state *sib,
+               struct ma_state *parent)
 {
        struct ma_state *mas;
        unsigned long min;
@@ -2938,7 +2934,8 @@ static inline bool rebalance_ascend(struct maple_copy *cp,
                return false;
 
        cp->height++;
-       mas_ascend(mas);
+       parent->alloc = mas->alloc;
+       *mas = *parent;
        wr_mas_setup(wr_mas, mas);
        wr_mas->offset_end = mas->offset;
        if (r == sib)
@@ -3732,8 +3729,9 @@ static inline void mas_wr_append(struct ma_wr_state *wr_mas)
  * Return: true if another split operation on the next level is needed, false
  * otherwise
  */
-static bool split_ascend(struct maple_copy *cp,
-               struct ma_wr_state *wr_mas, struct ma_state *sib)
+static inline bool split_ascend(struct maple_copy *cp,
+               struct ma_wr_state *wr_mas, struct ma_state *sib,
+               struct ma_state *parent)
 {
        struct ma_state *mas;
        unsigned long min, max;
@@ -3756,7 +3754,9 @@ static bool split_ascend(struct maple_copy *cp,
                return false;
 
        cp->height++;
-       mas_ascend(mas);
+       BUG_ON(mas->node == parent->node);
+       parent->alloc = mas->alloc;
+       *mas = *parent;
        wr_mas_setup(wr_mas, mas);
        wr_mas->offset_end = mas->offset;
        if (sib->end) {
@@ -3780,8 +3780,9 @@ static bool split_ascend(struct maple_copy *cp,
  * indicate it will not be used.
  *
  */
-static void split_data(struct maple_copy *cp,
-               struct ma_wr_state *wr_mas, struct ma_state *sib)
+static inline void split_data(struct maple_copy *cp,
+               struct ma_wr_state *wr_mas, struct ma_state *sib,
+               struct ma_state *parent)
 {
        cp_data_calc(cp, wr_mas, wr_mas);
        if (cp->data <= mt_slots[wr_mas->type]) {
@@ -3790,7 +3791,7 @@ static void split_data(struct maple_copy *cp,
                return;
        }
 
-       push_data_sib(cp, wr_mas->mas, sib);
+       push_data_sib(cp, wr_mas->mas, sib, parent);
        if (sib->end)
                cp->data += sib->end + 1;
 }
@@ -3804,16 +3805,22 @@ static void mas_wr_split(struct ma_wr_state *wr_mas)
        struct ma_state *mas;
        struct maple_copy cp;
        struct ma_state sib;
+       struct ma_state parent;
 
        mas = wr_mas->mas;
+       parent = *mas;
        trace_ma_op(__func__, mas);
        cp_leaf_init(&cp, mas, wr_mas, wr_mas);
        do {
-               split_data(&cp, wr_mas, &sib);
+               if (!mte_is_root(parent.node)) {
+                       mas_ascend(&parent);
+                       parent.end = mas_data_end(&parent);
+               }
+               split_data(&cp, wr_mas, &sib, &parent);
                multi_src_setup(&cp, wr_mas, wr_mas, &sib);
                dst_setup(&cp, mas, wr_mas->type);
                cp_data_write(&cp, mas);
-       } while (split_ascend(&cp, wr_mas, &sib));
+       } while (split_ascend(&cp, wr_mas, &sib, &parent));
 
        mas_wmb_replace(mas, &cp);
 }
@@ -3832,6 +3839,7 @@ static void mas_wr_rebalance(struct ma_wr_state *wr_mas)
        struct ma_state *mas;
        struct maple_copy cp;
        struct ma_state sib;
+       struct ma_state parent;
 
        /*
         * Rebalancing occurs if a node is insufficient.  Data is rebalanced
@@ -3845,13 +3853,18 @@ static void mas_wr_rebalance(struct ma_wr_state *wr_mas)
 
        mas = wr_mas->mas;
        trace_ma_op(__func__, mas);
+       parent = *mas;
        cp_leaf_init(&cp, mas, wr_mas, wr_mas);
        do {
-               rebalance_data(&cp, wr_mas, &sib);
+               if (!mte_is_root(parent.node)) {
+                       mas_ascend(&parent);
+                       parent.end = mas_data_end(&parent);
+               }
+               rebalance_data(&cp, wr_mas, &sib, &parent);
                multi_src_setup(&cp, wr_mas, wr_mas, &sib);
                dst_setup(&cp, mas, wr_mas->type);
                cp_data_write(&cp, mas);
-       } while (rebalance_ascend(&cp, wr_mas, &sib));
+       } while (rebalance_ascend(&cp, wr_mas, &sib, &parent));
 
        mas_wmb_replace(mas, &cp);
 }