[PATCH v8 63/63] radix tree: Remove unused functions

From: Matthew Wilcox
Date: Tue Mar 06 2018 - 14:25:59 EST


From: Matthew Wilcox <mawilcox@xxxxxxxxxxxxx>

The following functions are (now) unused:
- __radix_tree_delete_node
- radix_tree_gang_lookup_slot
- radix_tree_join
- radix_tree_maybe_preload_order
- radix_tree_split
- radix_tree_split_preload

Signed-off-by: Matthew Wilcox <mawilcox@xxxxxxxxxxxxx>
---
include/linux/radix-tree.h | 16 +--
lib/radix-tree.c | 294 +--------------------------------------------
2 files changed, 4 insertions(+), 306 deletions(-)

diff --git a/include/linux/radix-tree.h b/include/linux/radix-tree.h
index f64beb9ba175..eb2ae901f2ec 100644
--- a/include/linux/radix-tree.h
+++ b/include/linux/radix-tree.h
@@ -147,12 +147,11 @@ static inline unsigned int iter_shift(const struct radix_tree_iter *iter)
* radix_tree_lookup_slot
* radix_tree_tag_get
* radix_tree_gang_lookup
- * radix_tree_gang_lookup_slot
* radix_tree_gang_lookup_tag
* radix_tree_gang_lookup_tag_slot
* radix_tree_tagged
*
- * The first 8 functions are able to be called locklessly, using RCU. The
+ * The first 7 functions are able to be called locklessly, using RCU. The
* caller must ensure calls to these functions are made within rcu_read_lock()
* regions. Other readers (lock-free or otherwise) and modifications may be
* running concurrently.
@@ -254,9 +253,6 @@ void radix_tree_iter_replace(struct radix_tree_root *,
const struct radix_tree_iter *, void __rcu **slot, void *entry);
void radix_tree_replace_slot(struct radix_tree_root *,
void __rcu **slot, void *entry);
-void __radix_tree_delete_node(struct radix_tree_root *,
- struct radix_tree_node *,
- radix_tree_update_node_t update_node);
void radix_tree_iter_delete(struct radix_tree_root *,
struct radix_tree_iter *iter, void __rcu **slot);
void *radix_tree_delete_item(struct radix_tree_root *, unsigned long, void *);
@@ -266,12 +262,8 @@ void radix_tree_clear_tags(struct radix_tree_root *, struct radix_tree_node *,
unsigned int radix_tree_gang_lookup(const struct radix_tree_root *,
void **results, unsigned long first_index,
unsigned int max_items);
-unsigned int radix_tree_gang_lookup_slot(const struct radix_tree_root *,
- void __rcu ***results, unsigned long *indices,
- unsigned long first_index, unsigned int max_items);
int radix_tree_preload(gfp_t gfp_mask);
int radix_tree_maybe_preload(gfp_t gfp_mask);
-int radix_tree_maybe_preload_order(gfp_t gfp_mask, int order);
void radix_tree_init(void);
void *radix_tree_tag_set(struct radix_tree_root *,
unsigned long index, unsigned int tag);
@@ -296,12 +288,6 @@ static inline void radix_tree_preload_end(void)
preempt_enable();
}

-int radix_tree_split_preload(unsigned old_order, unsigned new_order, gfp_t);
-int radix_tree_split(struct radix_tree_root *, unsigned long index,
- unsigned new_order);
-int radix_tree_join(struct radix_tree_root *, unsigned long index,
- unsigned new_order, void *);
-
void __rcu **idr_get_free(struct radix_tree_root *root,
struct radix_tree_iter *iter, gfp_t gfp,
unsigned long max);
diff --git a/lib/radix-tree.c b/lib/radix-tree.c
index 71697bd25140..20858120ac0b 100644
--- a/lib/radix-tree.c
+++ b/lib/radix-tree.c
@@ -41,9 +41,6 @@
#include <linux/xarray.h>


-/* Number of nodes in fully populated tree of given height */
-static unsigned long height_to_maxnodes[RADIX_TREE_MAX_PATH + 1] __read_mostly;
-
/*
* Radix tree node cache.
*/
@@ -463,73 +460,6 @@ int radix_tree_maybe_preload(gfp_t gfp_mask)
}
EXPORT_SYMBOL(radix_tree_maybe_preload);

-#ifdef CONFIG_RADIX_TREE_MULTIORDER
-/*
- * Preload with enough objects to ensure that we can split a single entry
- * of order @old_order into many entries of size @new_order
- */
-int radix_tree_split_preload(unsigned int old_order, unsigned int new_order,
- gfp_t gfp_mask)
-{
- unsigned top = 1 << (old_order % RADIX_TREE_MAP_SHIFT);
- unsigned layers = (old_order / RADIX_TREE_MAP_SHIFT) -
- (new_order / RADIX_TREE_MAP_SHIFT);
- unsigned nr = 0;
-
- WARN_ON_ONCE(!gfpflags_allow_blocking(gfp_mask));
- BUG_ON(new_order >= old_order);
-
- while (layers--)
- nr = nr * RADIX_TREE_MAP_SIZE + 1;
- return __radix_tree_preload(gfp_mask, top * nr);
-}
-#endif
-
-/*
- * The same as function above, but preload number of nodes required to insert
- * (1 << order) continuous naturally-aligned elements.
- */
-int radix_tree_maybe_preload_order(gfp_t gfp_mask, int order)
-{
- unsigned long nr_subtrees;
- int nr_nodes, subtree_height;
-
- /* Preloading doesn't help anything with this gfp mask, skip it */
- if (!gfpflags_allow_blocking(gfp_mask)) {
- preempt_disable();
- return 0;
- }
-
- /*
- * Calculate number and height of fully populated subtrees it takes to
- * store (1 << order) elements.
- */
- nr_subtrees = 1 << order;
- for (subtree_height = 0; nr_subtrees > RADIX_TREE_MAP_SIZE;
- subtree_height++)
- nr_subtrees >>= RADIX_TREE_MAP_SHIFT;
-
- /*
- * The worst case is zero height tree with a single item at index 0 and
- * then inserting items starting at ULONG_MAX - (1 << order).
- *
- * This requires RADIX_TREE_MAX_PATH nodes to build branch from root to
- * 0-index item.
- */
- nr_nodes = RADIX_TREE_MAX_PATH;
-
- /* Plus branch to fully populated subtrees. */
- nr_nodes += RADIX_TREE_MAX_PATH - subtree_height;
-
- /* Root node is shared. */
- nr_nodes--;
-
- /* Plus nodes required to build subtrees. */
- nr_nodes += nr_subtrees * height_to_maxnodes[subtree_height];
-
- return __radix_tree_preload(gfp_mask, nr_nodes);
-}
-
static unsigned radix_tree_load_root(const struct radix_tree_root *root,
struct radix_tree_node **nodep, unsigned long *maxindex)
{
@@ -1138,7 +1068,7 @@ void __radix_tree_replace(struct radix_tree_root *root,
* @slot: pointer to slot
* @item: new item to store in the slot.
*
- * For use with radix_tree_lookup_slot(), radix_tree_gang_lookup_slot(),
+ * For use with radix_tree_lookup_slot() and
* radix_tree_gang_lookup_tag_slot(). Caller must hold tree write locked
* across slot lookup and replacement.
*
@@ -1161,8 +1091,8 @@ EXPORT_SYMBOL(radix_tree_replace_slot);
* @slot: pointer to slot
* @item: new item to store in the slot.
*
- * For use with radix_tree_split() and radix_tree_for_each_slot().
- * Caller must hold tree write locked across split and replacement.
+ * For use with radix_tree_for_each_slot().
+ * Caller must hold tree write locked.
*/
void radix_tree_iter_replace(struct radix_tree_root *root,
const struct radix_tree_iter *iter,
@@ -1171,151 +1101,6 @@ void radix_tree_iter_replace(struct radix_tree_root *root,
__radix_tree_replace(root, iter->node, slot, item, NULL);
}

-#ifdef CONFIG_RADIX_TREE_MULTIORDER
-/**
- * radix_tree_join - replace multiple entries with one multiorder entry
- * @root: radix tree root
- * @index: an index inside the new entry
- * @order: order of the new entry
- * @item: new entry
- *
- * Call this function to replace several entries with one larger entry.
- * The existing entries are presumed to not need freeing as a result of
- * this call.
- *
- * The replacement entry will have all the tags set on it that were set
- * on any of the entries it is replacing.
- */
-int radix_tree_join(struct radix_tree_root *root, unsigned long index,
- unsigned order, void *item)
-{
- struct radix_tree_node *node;
- void __rcu **slot;
- int error;
-
- BUG_ON(radix_tree_is_internal_node(item));
-
- error = __radix_tree_create(root, index, order, &node, &slot);
- if (!error)
- error = insert_entries(node, slot, item, order, true);
- if (error > 0)
- error = 0;
-
- return error;
-}
-
-/**
- * radix_tree_split - Split an entry into smaller entries
- * @root: radix tree root
- * @index: An index within the large entry
- * @order: Order of new entries
- *
- * Call this function as the first step in replacing a multiorder entry
- * with several entries of lower order. After this function returns,
- * loop over the relevant portion of the tree using radix_tree_for_each_slot()
- * and call radix_tree_iter_replace() to set up each new entry.
- *
- * The tags from this entry are replicated to all the new entries.
- *
- * The radix tree should be locked against modification during the entire
- * replacement operation. Lock-free lookups will see RADIX_TREE_RETRY which
- * should prompt RCU walkers to restart the lookup from the root.
- */
-int radix_tree_split(struct radix_tree_root *root, unsigned long index,
- unsigned order)
-{
- struct radix_tree_node *parent, *node, *child;
- void __rcu **slot;
- unsigned int offset, end;
- unsigned n, tag, tags = 0;
- gfp_t gfp = root_gfp_mask(root);
-
- if (!__radix_tree_lookup(root, index, &parent, &slot))
- return -ENOENT;
- if (!parent)
- return -ENOENT;
-
- offset = get_slot_offset(parent, slot);
-
- for (tag = 0; tag < RADIX_TREE_MAX_TAGS; tag++)
- if (tag_get(parent, tag, offset))
- tags |= 1 << tag;
-
- for (end = offset + 1; end < RADIX_TREE_MAP_SIZE; end++) {
- if (!xa_is_sibling(rcu_dereference_raw(parent->slots[end])))
- break;
- for (tag = 0; tag < RADIX_TREE_MAX_TAGS; tag++)
- if (tags & (1 << tag))
- tag_set(parent, tag, end);
- /* rcu_assign_pointer ensures tags are set before RETRY */
- rcu_assign_pointer(parent->slots[end], RADIX_TREE_RETRY);
- }
- rcu_assign_pointer(parent->slots[offset], RADIX_TREE_RETRY);
- parent->nr_values -= (end - offset);
-
- if (order == parent->shift)
- return 0;
- if (order > parent->shift) {
- while (offset < end)
- offset += insert_entries(parent, &parent->slots[offset],
- RADIX_TREE_RETRY, order, true);
- return 0;
- }
-
- node = parent;
-
- for (;;) {
- if (node->shift > order) {
- child = radix_tree_node_alloc(gfp, node, root,
- node->shift - RADIX_TREE_MAP_SHIFT,
- offset, 0, 0);
- if (!child)
- goto nomem;
- if (node != parent) {
- node->count++;
- rcu_assign_pointer(node->slots[offset],
- node_to_entry(child));
- for (tag = 0; tag < RADIX_TREE_MAX_TAGS; tag++)
- if (tags & (1 << tag))
- tag_set(node, tag, offset);
- }
-
- node = child;
- offset = 0;
- continue;
- }
-
- n = insert_entries(node, &node->slots[offset],
- RADIX_TREE_RETRY, order, false);
- BUG_ON(n > RADIX_TREE_MAP_SIZE);
-
- for (tag = 0; tag < RADIX_TREE_MAX_TAGS; tag++)
- if (tags & (1 << tag))
- tag_set(node, tag, offset);
- offset += n;
-
- while (offset == RADIX_TREE_MAP_SIZE) {
- if (node == parent)
- break;
- offset = node->offset;
- child = node;
- node = node->parent;
- rcu_assign_pointer(node->slots[offset],
- node_to_entry(child));
- offset++;
- }
- if ((node == parent) && (offset == end))
- return 0;
- }
-
- nomem:
- /* Shouldn't happen; did user forget to preload? */
- /* TODO: free all the allocated nodes */
- WARN_ON(1);
- return -ENOMEM;
-}
-#endif
-
static void node_tag_set(struct radix_tree_root *root,
struct radix_tree_node *node,
unsigned int tag, unsigned int offset)
@@ -1772,48 +1557,6 @@ radix_tree_gang_lookup(const struct radix_tree_root *root, void **results,
}
EXPORT_SYMBOL(radix_tree_gang_lookup);

-/**
- * radix_tree_gang_lookup_slot - perform multiple slot lookup on radix tree
- * @root: radix tree root
- * @results: where the results of the lookup are placed
- * @indices: where their indices should be placed (but usually NULL)
- * @first_index: start the lookup from this key
- * @max_items: place up to this many items at *results
- *
- * Performs an index-ascending scan of the tree for present items. Places
- * their slots at *@results and returns the number of items which were
- * placed at *@results.
- *
- * The implementation is naive.
- *
- * Like radix_tree_gang_lookup as far as RCU and locking goes. Slots must
- * be dereferenced with radix_tree_deref_slot, and if using only RCU
- * protection, radix_tree_deref_slot may fail requiring a retry.
- */
-unsigned int
-radix_tree_gang_lookup_slot(const struct radix_tree_root *root,
- void __rcu ***results, unsigned long *indices,
- unsigned long first_index, unsigned int max_items)
-{
- struct radix_tree_iter iter;
- void __rcu **slot;
- unsigned int ret = 0;
-
- if (unlikely(!max_items))
- return 0;
-
- radix_tree_for_each_slot(slot, root, &iter, first_index) {
- results[ret] = slot;
- if (indices)
- indices[ret] = iter.index;
- if (++ret == max_items)
- break;
- }
-
- return ret;
-}
-EXPORT_SYMBOL(radix_tree_gang_lookup_slot);
-
/**
* radix_tree_gang_lookup_tag - perform multiple lookup on a radix tree
* based on a tag
@@ -1890,23 +1633,6 @@ radix_tree_gang_lookup_tag_slot(const struct radix_tree_root *root,
}
EXPORT_SYMBOL(radix_tree_gang_lookup_tag_slot);

-/**
- * __radix_tree_delete_node - try to free node after clearing a slot
- * @root: radix tree root
- * @node: node containing @index
- * @update_node: callback for changing leaf nodes
- *
- * After clearing the slot at @index in @node from radix tree
- * rooted at @root, call this function to attempt freeing the
- * node and shrinking the tree.
- */
-void __radix_tree_delete_node(struct radix_tree_root *root,
- struct radix_tree_node *node,
- radix_tree_update_node_t update_node)
-{
- delete_node(root, node, update_node);
-}
-
static bool __radix_tree_delete(struct radix_tree_root *root,
struct radix_tree_node *node, void __rcu **slot)
{
@@ -2173,19 +1899,6 @@ static __init unsigned long __maxindex(unsigned int height)
return ~0UL >> shift;
}

-static __init void radix_tree_init_maxnodes(void)
-{
- unsigned long height_to_maxindex[RADIX_TREE_MAX_PATH + 1];
- unsigned int i, j;
-
- for (i = 0; i < ARRAY_SIZE(height_to_maxindex); i++)
- height_to_maxindex[i] = __maxindex(i);
- for (i = 0; i < ARRAY_SIZE(height_to_maxnodes); i++) {
- for (j = i; j > 0; j--)
- height_to_maxnodes[i] += height_to_maxindex[j - 1] + 1;
- }
-}
-
static int radix_tree_cpu_dead(unsigned int cpu)
{
struct radix_tree_preload *rtp;
@@ -2215,7 +1928,6 @@ void __init radix_tree_init(void)
sizeof(struct radix_tree_node), 0,
SLAB_PANIC | SLAB_RECLAIM_ACCOUNT,
radix_tree_node_ctor);
- radix_tree_init_maxnodes();
ret = cpuhp_setup_state_nocalls(CPUHP_RADIX_DEAD, "lib/radix:dead",
NULL, radix_tree_cpu_dead);
WARN_ON(ret < 0);
--
2.16.1