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radix tree: Remove split/join code

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radix_tree_split and radix_tree_join were never used upstream.  Remove
them; if they're needed in future they will be replaced by XArray
equivalents.

Signed-off-by: Matthew Wilcox <willy@infradead.org>
This commit is contained in:
Matthew Wilcox 2018-05-19 16:47:47 -04:00
parent 1cf56f9d67
commit 2956c6644b
4 changed files with 2 additions and 513 deletions
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6
include/linux/radix-tree.h
View File

@ -284,12 +284,6 @@ 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);

171
lib/radix-tree.c
View File

@ -415,28 +415,6 @@ 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.
@ -1111,8 +1089,8 @@ 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,
@ -1121,151 +1099,6 @@ void radix_tree_iter_replace(struct radix_tree_root *root,
__radix_tree_replace(root, iter->node, slot, item);
}
#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)

91
tools/testing/radix-tree/benchmark.c
View File

@ -146,90 +146,6 @@ static void benchmark_size(unsigned long size, unsigned long step, int order)
rcu_barrier();
}
static long long __benchmark_split(unsigned long index,
int old_order, int new_order)
{
struct timespec start, finish;
long long nsec;
RADIX_TREE(tree, GFP_ATOMIC);
item_insert_order(&tree, index, old_order);
clock_gettime(CLOCK_MONOTONIC, &start);
radix_tree_split(&tree, index, new_order);
clock_gettime(CLOCK_MONOTONIC, &finish);
nsec = (finish.tv_sec - start.tv_sec) * NSEC_PER_SEC +
(finish.tv_nsec - start.tv_nsec);
item_kill_tree(&tree);
return nsec;
}
static void benchmark_split(unsigned long size, unsigned long step)
{
int i, j, idx;
long long nsec = 0;
for (idx = 0; idx < size; idx += step) {
for (i = 3; i < 11; i++) {
for (j = 0; j < i; j++) {
nsec += __benchmark_split(idx, i, j);
}
}
}
printv(2, "Size %8ld, step %8ld, split time %10lld ns\n",
size, step, nsec);
}
static long long __benchmark_join(unsigned long index,
unsigned order1, unsigned order2)
{
unsigned long loc;
struct timespec start, finish;
long long nsec;
void *item, *item2 = item_create(index + 1, order1);
RADIX_TREE(tree, GFP_KERNEL);
item_insert_order(&tree, index, order2);
item = radix_tree_lookup(&tree, index);
clock_gettime(CLOCK_MONOTONIC, &start);
radix_tree_join(&tree, index + 1, order1, item2);
clock_gettime(CLOCK_MONOTONIC, &finish);
nsec = (finish.tv_sec - start.tv_sec) * NSEC_PER_SEC +
(finish.tv_nsec - start.tv_nsec);
loc = find_item(&tree, item);
if (loc == -1)
free(item);
item_kill_tree(&tree);
return nsec;
}
static void benchmark_join(unsigned long step)
{
int i, j, idx;
long long nsec = 0;
for (idx = 0; idx < 1 << 10; idx += step) {
for (i = 1; i < 15; i++) {
for (j = 0; j < i; j++) {
nsec += __benchmark_join(idx, i, j);
}
}
}
printv(2, "Size %8d, step %8ld, join time %10lld ns\n",
1 << 10, step, nsec);
}
void benchmark(void)
{
unsigned long size[] = {1 << 10, 1 << 20, 0};
@ -247,11 +163,4 @@ void benchmark(void)
for (c = 0; size[c]; c++)
for (s = 0; step[s]; s++)
benchmark_size(size[c], step[s] << 9, 9);
for (c = 0; size[c]; c++)
for (s = 0; step[s]; s++)
benchmark_split(size[c], step[s]);
for (s = 0; step[s]; s++)
benchmark_join(step[s]);
}

247
tools/testing/radix-tree/multiorder.c
View File

@ -356,251 +356,6 @@ void multiorder_tagged_iteration(void)
item_kill_tree(&tree);
}
/*
* Basic join checks: make sure we can't find an entry in the tree after
* a larger entry has replaced it
*/
static void multiorder_join1(unsigned long index,
unsigned order1, unsigned order2)
{
unsigned long loc;
void *item, *item2 = item_create(index + 1, order1);
RADIX_TREE(tree, GFP_KERNEL);
item_insert_order(&tree, index, order2);
item = radix_tree_lookup(&tree, index);
radix_tree_join(&tree, index + 1, order1, item2);
loc = find_item(&tree, item);
if (loc == -1)
free(item);
item = radix_tree_lookup(&tree, index + 1);
assert(item == item2);
item_kill_tree(&tree);
}
/*
* Check that the accounting of value entries is handled correctly
* by joining a value entry to a normal pointer.
*/
static void multiorder_join2(unsigned order1, unsigned order2)
{
RADIX_TREE(tree, GFP_KERNEL);
struct radix_tree_node *node;
void *item1 = item_create(0, order1);
void *item2;
item_insert_order(&tree, 0, order2);
radix_tree_insert(&tree, 1 << order2, xa_mk_value(5));
item2 = __radix_tree_lookup(&tree, 1 << order2, &node, NULL);
assert(item2 == xa_mk_value(5));
assert(node->nr_values == 1);
item2 = radix_tree_lookup(&tree, 0);
free(item2);
radix_tree_join(&tree, 0, order1, item1);
item2 = __radix_tree_lookup(&tree, 1 << order2, &node, NULL);
assert(item2 == item1);
assert(node->nr_values == 0);
item_kill_tree(&tree);
}
/*
* This test revealed an accounting bug for value entries at one point.
* Nodes were being freed back into the pool with an elevated exception count
* by radix_tree_join() and then radix_tree_split() was failing to zero the
* count of value entries.
*/
static void multiorder_join3(unsigned int order)
{
RADIX_TREE(tree, GFP_KERNEL);
struct radix_tree_node *node;
void **slot;
struct radix_tree_iter iter;
unsigned long i;
for (i = 0; i < (1 << order); i++) {
radix_tree_insert(&tree, i, xa_mk_value(5));
}
radix_tree_join(&tree, 0, order, xa_mk_value(7));
rcu_barrier();
radix_tree_split(&tree, 0, 0);
radix_tree_for_each_slot(slot, &tree, &iter, 0) {
radix_tree_iter_replace(&tree, &iter, slot, xa_mk_value(5));
}
__radix_tree_lookup(&tree, 0, &node, NULL);
assert(node->nr_values == node->count);
item_kill_tree(&tree);
}
static void multiorder_join(void)
{
int i, j, idx;
for (idx = 0; idx < 1024; idx = idx * 2 + 3) {
for (i = 1; i < 15; i++) {
for (j = 0; j < i; j++) {
multiorder_join1(idx, i, j);
}
}
}
for (i = 1; i < 15; i++) {
for (j = 0; j < i; j++) {
multiorder_join2(i, j);
}
}
for (i = 3; i < 10; i++) {
multiorder_join3(i);
}
}
static void check_mem(unsigned old_order, unsigned new_order, unsigned alloc)
{
struct radix_tree_preload *rtp = &radix_tree_preloads;
if (rtp->nr != 0)
printv(2, "split(%u %u) remaining %u\n", old_order, new_order,
rtp->nr);
/*
* Can't check for equality here as some nodes may have been
* RCU-freed while we ran. But we should never finish with more
* nodes allocated since they should have all been preloaded.
*/
if (nr_allocated > alloc)
printv(2, "split(%u %u) allocated %u %u\n", old_order, new_order,
alloc, nr_allocated);
}
static void __multiorder_split(int old_order, int new_order)
{
RADIX_TREE(tree, GFP_ATOMIC);
void **slot;
struct radix_tree_iter iter;
unsigned alloc;
struct item *item;
radix_tree_preload(GFP_KERNEL);
assert(item_insert_order(&tree, 0, old_order) == 0);
radix_tree_preload_end();
/* Wipe out the preloaded cache or it'll confuse check_mem() */
radix_tree_cpu_dead(0);
item = radix_tree_tag_set(&tree, 0, 2);
radix_tree_split_preload(old_order, new_order, GFP_KERNEL);
alloc = nr_allocated;
radix_tree_split(&tree, 0, new_order);
check_mem(old_order, new_order, alloc);
radix_tree_for_each_slot(slot, &tree, &iter, 0) {
radix_tree_iter_replace(&tree, &iter, slot,
item_create(iter.index, new_order));
}
radix_tree_preload_end();
item_kill_tree(&tree);
free(item);
}
static void __multiorder_split2(int old_order, int new_order)
{
RADIX_TREE(tree, GFP_KERNEL);
void **slot;
struct radix_tree_iter iter;
struct radix_tree_node *node;
void *item;
__radix_tree_insert(&tree, 0, old_order, xa_mk_value(5));
item = __radix_tree_lookup(&tree, 0, &node, NULL);
assert(item == xa_mk_value(5));
assert(node->nr_values > 0);
radix_tree_split(&tree, 0, new_order);
radix_tree_for_each_slot(slot, &tree, &iter, 0) {
radix_tree_iter_replace(&tree, &iter, slot,
item_create(iter.index, new_order));
}
item = __radix_tree_lookup(&tree, 0, &node, NULL);
assert(item != xa_mk_value(5));
assert(node->nr_values == 0);
item_kill_tree(&tree);
}
static void __multiorder_split3(int old_order, int new_order)
{
RADIX_TREE(tree, GFP_KERNEL);
void **slot;
struct radix_tree_iter iter;
struct radix_tree_node *node;
void *item;
__radix_tree_insert(&tree, 0, old_order, xa_mk_value(5));
item = __radix_tree_lookup(&tree, 0, &node, NULL);
assert(item == xa_mk_value(5));
assert(node->nr_values > 0);
radix_tree_split(&tree, 0, new_order);
radix_tree_for_each_slot(slot, &tree, &iter, 0) {
radix_tree_iter_replace(&tree, &iter, slot, xa_mk_value(7));
}
item = __radix_tree_lookup(&tree, 0, &node, NULL);
assert(item == xa_mk_value(7));
assert(node->nr_values > 0);
item_kill_tree(&tree);
__radix_tree_insert(&tree, 0, old_order, xa_mk_value(5));
item = __radix_tree_lookup(&tree, 0, &node, NULL);
assert(item == xa_mk_value(5));
assert(node->nr_values > 0);
radix_tree_split(&tree, 0, new_order);
radix_tree_for_each_slot(slot, &tree, &iter, 0) {
if (iter.index == (1 << new_order))
radix_tree_iter_replace(&tree, &iter, slot,
xa_mk_value(7));
else
radix_tree_iter_replace(&tree, &iter, slot, NULL);
}
item = __radix_tree_lookup(&tree, 1 << new_order, &node, NULL);
assert(item == xa_mk_value(7));
assert(node->count == node->nr_values);
do {
node = node->parent;
if (!node)
break;
assert(node->count == 1);
assert(node->nr_values == 0);
} while (1);
item_kill_tree(&tree);
}
static void multiorder_split(void)
{
int i, j;
for (i = 3; i < 11; i++)
for (j = 0; j < i; j++) {
__multiorder_split(i, j);
__multiorder_split2(i, j);
__multiorder_split3(i, j);
}
}
static void multiorder_account(void)
{
RADIX_TREE(tree, GFP_KERNEL);
@ -702,8 +457,6 @@ void multiorder_checks(void)
multiorder_tag_tests();
multiorder_iteration();
multiorder_tagged_iteration();
multiorder_join();
multiorder_split();
multiorder_account();
multiorder_iteration_race();