diff options
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/Kconfig.debug | 6 | ||||
| -rw-r--r-- | lib/Makefile | 3 | ||||
| -rw-r--r-- | lib/prio_tree.c | 455 | ||||
| -rw-r--r-- | lib/prio_tree_test.c | 106 |
4 files changed, 1 insertions, 569 deletions
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index ee9f030b695..a6e7e774152 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -1289,12 +1289,6 @@ config RBTREE_TEST A benchmark measuring the performance of the rbtree library. Also includes rbtree invariant checks. -config PRIO_TREE_TEST - tristate "Prio tree test" - depends on m && DEBUG_KERNEL - help - A benchmark measuring the performance of the prio tree library - config INTERVAL_TREE_TEST tristate "Interval tree test" depends on m && DEBUG_KERNEL diff --git a/lib/Makefile b/lib/Makefile index 26f578bf616..3128e357e28 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -9,7 +9,7 @@ endif lib-y := ctype.o string.o vsprintf.o cmdline.o \ rbtree.o radix-tree.o dump_stack.o timerqueue.o\ - idr.o int_sqrt.o extable.o prio_tree.o \ + idr.o int_sqrt.o extable.o \ sha1.o md5.o irq_regs.o reciprocal_div.o argv_split.o \ proportions.o flex_proportions.o prio_heap.o ratelimit.o show_mem.o \ is_single_threaded.o plist.o decompress.o @@ -141,7 +141,6 @@ $(foreach file, $(libfdt_files), \ lib-$(CONFIG_LIBFDT) += $(libfdt_files) obj-$(CONFIG_RBTREE_TEST) += rbtree_test.o -obj-$(CONFIG_PRIO_TREE_TEST) += prio_tree_test.o obj-$(CONFIG_INTERVAL_TREE_TEST) += interval_tree_test.o interval_tree_test-objs := interval_tree_test_main.o interval_tree.o diff --git a/lib/prio_tree.c b/lib/prio_tree.c deleted file mode 100644 index bba37148c15..00000000000 --- a/lib/prio_tree.c +++ /dev/null @@ -1,455 +0,0 @@ -/* - * lib/prio_tree.c - priority search tree - * - * Copyright (C) 2004, Rajesh Venkatasubramanian <vrajesh@umich.edu> - * - * This file is released under the GPL v2. - * - * Based on the radix priority search tree proposed by Edward M. McCreight - * SIAM Journal of Computing, vol. 14, no.2, pages 257-276, May 1985 - * - * 02Feb2004 Initial version - */ - -#include <linux/init.h> -#include <linux/mm.h> -#include <linux/prio_tree.h> -#include <linux/export.h> - -/* - * A clever mix of heap and radix trees forms a radix priority search tree (PST) - * which is useful for storing intervals, e.g, we can consider a vma as a closed - * interval of file pages [offset_begin, offset_end], and store all vmas that - * map a file in a PST. Then, using the PST, we can answer a stabbing query, - * i.e., selecting a set of stored intervals (vmas) that overlap with (map) a - * given input interval X (a set of consecutive file pages), in "O(log n + m)" - * time where 'log n' is the height of the PST, and 'm' is the number of stored - * intervals (vmas) that overlap (map) with the input interval X (the set of - * consecutive file pages). - * - * In our implementation, we store closed intervals of the form [radix_index, - * heap_index]. We assume that always radix_index <= heap_index. McCreight's PST - * is designed for storing intervals with unique radix indices, i.e., each - * interval have different radix_index. However, this limitation can be easily - * overcome by using the size, i.e., heap_index - radix_index, as part of the - * index, so we index the tree using [(radix_index,size), heap_index]. - * - * When the above-mentioned indexing scheme is used, theoretically, in a 32 bit - * machine, the maximum height of a PST can be 64. We can use a balanced version - * of the priority search tree to optimize the tree height, but the balanced - * tree proposed by McCreight is too complex and memory-hungry for our purpose. - */ - -/* - * The following macros are used for implementing prio_tree for i_mmap - */ - -static void get_index(const struct prio_tree_root *root, - const struct prio_tree_node *node, - unsigned long *radix, unsigned long *heap) -{ - *radix = node->start; - *heap = node->last; -} - -static unsigned long index_bits_to_maxindex[BITS_PER_LONG]; - -void __init prio_tree_init(void) -{ - unsigned int i; - - for (i = 0; i < ARRAY_SIZE(index_bits_to_maxindex) - 1; i++) - index_bits_to_maxindex[i] = (1UL << (i + 1)) - 1; - index_bits_to_maxindex[ARRAY_SIZE(index_bits_to_maxindex) - 1] = ~0UL; -} - -/* - * Maximum heap_index that can be stored in a PST with index_bits bits - */ -static inline unsigned long prio_tree_maxindex(unsigned int bits) -{ - return index_bits_to_maxindex[bits - 1]; -} - -static void prio_set_parent(struct prio_tree_node *parent, - struct prio_tree_node *child, bool left) -{ - if (left) - parent->left = child; - else - parent->right = child; - - child->parent = parent; -} - -/* - * Extend a priority search tree so that it can store a node with heap_index - * max_heap_index. In the worst case, this algorithm takes O((log n)^2). - * However, this function is used rarely and the common case performance is - * not bad. - */ -static struct prio_tree_node *prio_tree_expand(struct prio_tree_root *root, - struct prio_tree_node *node, unsigned long max_heap_index) -{ - struct prio_tree_node *prev; - - if (max_heap_index > prio_tree_maxindex(root->index_bits)) - root->index_bits++; - - prev = node; - INIT_PRIO_TREE_NODE(node); - - while (max_heap_index > prio_tree_maxindex(root->index_bits)) { - struct prio_tree_node *tmp = root->prio_tree_node; - - root->index_bits++; - - if (prio_tree_empty(root)) - continue; - - prio_tree_remove(root, root->prio_tree_node); - INIT_PRIO_TREE_NODE(tmp); - - prio_set_parent(prev, tmp, true); - prev = tmp; - } - - if (!prio_tree_empty(root)) - prio_set_parent(prev, root->prio_tree_node, true); - - root->prio_tree_node = node; - return node; -} - -/* - * Replace a prio_tree_node with a new node and return the old node - */ -struct prio_tree_node *prio_tree_replace(struct prio_tree_root *root, - struct prio_tree_node *old, struct prio_tree_node *node) -{ - INIT_PRIO_TREE_NODE(node); - - if (prio_tree_root(old)) { - BUG_ON(root->prio_tree_node != old); - /* - * We can reduce root->index_bits here. However, it is complex - * and does not help much to improve performance (IMO). - */ - root->prio_tree_node = node; - } else - prio_set_parent(old->parent, node, old->parent->left == old); - - if (!prio_tree_left_empty(old)) - prio_set_parent(node, old->left, true); - - if (!prio_tree_right_empty(old)) - prio_set_parent(node, old->right, false); - - return old; -} - -/* - * Insert a prio_tree_node @node into a radix priority search tree @root. The - * algorithm typically takes O(log n) time where 'log n' is the number of bits - * required to represent the maximum heap_index. In the worst case, the algo - * can take O((log n)^2) - check prio_tree_expand. - * - * If a prior node with same radix_index and heap_index is already found in - * the tree, then returns the address of the prior node. Otherwise, inserts - * @node into the tree and returns @node. - */ -struct prio_tree_node *prio_tree_insert(struct prio_tree_root *root, - struct prio_tree_node *node) -{ - struct prio_tree_node *cur, *res = node; - unsigned long radix_index, heap_index; - unsigned long r_index, h_index, index, mask; - int size_flag = 0; - - get_index(root, node, &radix_index, &heap_index); - - if (prio_tree_empty(root) || - heap_index > prio_tree_maxindex(root->index_bits)) - return prio_tree_expand(root, node, heap_index); - - cur = root->prio_tree_node; - mask = 1UL << (root->index_bits - 1); - - while (mask) { - get_index(root, cur, &r_index, &h_index); - - if (r_index == radix_index && h_index == heap_index) - return cur; - - if (h_index < heap_index || - (h_index == heap_index && r_index > radix_index)) { - struct prio_tree_node *tmp = node; - node = prio_tree_replace(root, cur, node); - cur = tmp; - /* swap indices */ - index = r_index; - r_index = radix_index; - radix_index = index; - index = h_index; - h_index = heap_index; - heap_index = index; - } - - if (size_flag) - index = heap_index - radix_index; - else - index = radix_index; - - if (index & mask) { - if (prio_tree_right_empty(cur)) { - INIT_PRIO_TREE_NODE(node); - prio_set_parent(cur, node, false); - return res; - } else - cur = cur->right; - } else { - if (prio_tree_left_empty(cur)) { - INIT_PRIO_TREE_NODE(node); - prio_set_parent(cur, node, true); - return res; - } else - cur = cur->left; - } - - mask >>= 1; - - if (!mask) { - mask = 1UL << (BITS_PER_LONG - 1); - size_flag = 1; - } - } - /* Should not reach here */ - BUG(); - return NULL; -} -EXPORT_SYMBOL(prio_tree_insert); - -/* - * Remove a prio_tree_node @node from a radix priority search tree @root. The - * algorithm takes O(log n) time where 'log n' is the number of bits required - * to represent the maximum heap_index. - */ -void prio_tree_remove(struct prio_tree_root *root, struct prio_tree_node *node) -{ - struct prio_tree_node *cur; - unsigned long r_index, h_index_right, h_index_left; - - cur = node; - - while (!prio_tree_left_empty(cur) || !prio_tree_right_empty(cur)) { - if (!prio_tree_left_empty(cur)) - get_index(root, cur->left, &r_index, &h_index_left); - else { - cur = cur->right; - continue; - } - - if (!prio_tree_right_empty(cur)) - get_index(root, cur->right, &r_index, &h_index_right); - else { - cur = cur->left; - continue; - } - - /* both h_index_left and h_index_right cannot be 0 */ - if (h_index_left >= h_index_right) - cur = cur->left; - else - cur = cur->right; - } - - if (prio_tree_root(cur)) { - BUG_ON(root->prio_tree_node != cur); - __INIT_PRIO_TREE_ROOT(root, root->raw); - return; - } - - if (cur->parent->right == cur) - cur->parent->right = cur->parent; - else - cur->parent->left = cur->parent; - - while (cur != node) - cur = prio_tree_replace(root, cur->parent, cur); -} -EXPORT_SYMBOL(prio_tree_remove); - -static void iter_walk_down(struct prio_tree_iter *iter) -{ - iter->mask >>= 1; - if (iter->mask) { - if (iter->size_level) - iter->size_level++; - return; - } - - if (iter->size_level) { - BUG_ON(!prio_tree_left_empty(iter->cur)); - BUG_ON(!prio_tree_right_empty(iter->cur)); - iter->size_level++; - iter->mask = ULONG_MAX; - } else { - iter->size_level = 1; - iter->mask = 1UL << (BITS_PER_LONG - 1); - } -} - -static void iter_walk_up(struct prio_tree_iter *iter) -{ - if (iter->mask == ULONG_MAX) - iter->mask = 1UL; - else if (iter->size_level == 1) - iter->mask = 1UL; - else - iter->mask <<= 1; - if (iter->size_level) - iter->size_level--; - if (!iter->size_level && (iter->value & iter->mask)) - iter->value ^= iter->mask; -} - -/* - * Following functions help to enumerate all prio_tree_nodes in the tree that - * overlap with the input interval X [radix_index, heap_index]. The enumeration - * takes O(log n + m) time where 'log n' is the height of the tree (which is - * proportional to # of bits required to represent the maximum heap_index) and - * 'm' is the number of prio_tree_nodes that overlap the interval X. - */ - -static struct prio_tree_node *prio_tree_left(struct prio_tree_iter *iter, - unsigned long *r_index, unsigned long *h_index) -{ - if (prio_tree_left_empty(iter->cur)) - return NULL; - - get_index(iter->root, iter->cur->left, r_index, h_index); - - if (iter->r_index <= *h_index) { - iter->cur = iter->cur->left; - iter_walk_down(iter); - return iter->cur; - } - - return NULL; -} - -static struct prio_tree_node *prio_tree_right(struct prio_tree_iter *iter, - unsigned long *r_index, unsigned long *h_index) -{ - unsigned long value; - - if (prio_tree_right_empty(iter->cur)) - return NULL; - - if (iter->size_level) - value = iter->value; - else - value = iter->value | iter->mask; - - if (iter->h_index < value) - return NULL; - - get_index(iter->root, iter->cur->right, r_index, h_index); - - if (iter->r_index <= *h_index) { - iter->cur = iter->cur->right; - iter_walk_down(iter); - return iter->cur; - } - - return NULL; -} - -static struct prio_tree_node *prio_tree_parent(struct prio_tree_iter *iter) -{ - iter->cur = iter->cur->parent; - iter_walk_up(iter); - return iter->cur; -} - -static inline int overlap(struct prio_tree_iter *iter, - unsigned long r_index, unsigned long h_index) -{ - return iter->h_index >= r_index && iter->r_index <= h_index; -} - -/* - * prio_tree_first: - * - * Get the first prio_tree_node that overlaps with the interval [radix_index, - * heap_index]. Note that always radix_index <= heap_index. We do a pre-order - * traversal of the tree. - */ -static struct prio_tree_node *prio_tree_first(struct prio_tree_iter *iter) -{ - struct prio_tree_root *root; - unsigned long r_index, h_index; - - INIT_PRIO_TREE_ITER(iter); - - root = iter->root; - if (prio_tree_empty(root)) - return NULL; - - get_index(root, root->prio_tree_node, &r_index, &h_index); - - if (iter->r_index > h_index) - return NULL; - - iter->mask = 1UL << (root->index_bits - 1); - iter->cur = root->prio_tree_node; - - while (1) { - if (overlap(iter, r_index, h_index)) - return iter->cur; - - if (prio_tree_left(iter, &r_index, &h_index)) - continue; - - if (prio_tree_right(iter, &r_index, &h_index)) - continue; - - break; - } - return NULL; -} - -/* - * prio_tree_next: - * - * Get the next prio_tree_node that overlaps with the input interval in iter - */ -struct prio_tree_node *prio_tree_next(struct prio_tree_iter *iter) -{ - unsigned long r_index, h_index; - - if (iter->cur == NULL) - return prio_tree_first(iter); - -repeat: - while (prio_tree_left(iter, &r_index, &h_index)) - if (overlap(iter, r_index, h_index)) - return iter->cur; - - while (!prio_tree_right(iter, &r_index, &h_index)) { - while (!prio_tree_root(iter->cur) && - iter->cur->parent->right == iter->cur) - prio_tree_parent(iter); - - if (prio_tree_root(iter->cur)) - return NULL; - - prio_tree_parent(iter); - } - - if (overlap(iter, r_index, h_index)) - return iter->cur; - - goto repeat; -} -EXPORT_SYMBOL(prio_tree_next); diff --git a/lib/prio_tree_test.c b/lib/prio_tree_test.c deleted file mode 100644 index c26084ddc6a..00000000000 --- a/lib/prio_tree_test.c +++ /dev/null @@ -1,106 +0,0 @@ -#include <linux/module.h> -#include <linux/prio_tree.h> -#include <linux/random.h> -#include <asm/timex.h> - -#define NODES 100 -#define PERF_LOOPS 100000 -#define SEARCHES 100 -#define SEARCH_LOOPS 10000 - -static struct prio_tree_root root; -static struct prio_tree_node nodes[NODES]; -static u32 queries[SEARCHES]; - -static struct rnd_state rnd; - -static inline unsigned long -search(unsigned long query, struct prio_tree_root *root) -{ - struct prio_tree_iter iter; - unsigned long results = 0; - - prio_tree_iter_init(&iter, root, query, query); - while (prio_tree_next(&iter)) - results++; - return results; -} - -static void init(void) -{ - int i; - for (i = 0; i < NODES; i++) { - u32 a = prandom32(&rnd), b = prandom32(&rnd); - if (a <= b) { - nodes[i].start = a; - nodes[i].last = b; - } else { - nodes[i].start = b; - nodes[i].last = a; - } - } - for (i = 0; i < SEARCHES; i++) - queries[i] = prandom32(&rnd); -} - -static int prio_tree_test_init(void) -{ - int i, j; - unsigned long results; - cycles_t time1, time2, time; - - printk(KERN_ALERT "prio tree insert/remove"); - - prandom32_seed(&rnd, 3141592653589793238ULL); - INIT_PRIO_TREE_ROOT(&root); - init(); - - time1 = get_cycles(); - - for (i = 0; i < PERF_LOOPS; i++) { - for (j = 0; j < NODES; j++) - prio_tree_insert(&root, nodes + j); - for (j = 0; j < NODES; j++) - prio_tree_remove(&root, nodes + j); - } - - time2 = get_cycles(); - time = time2 - time1; - - time = div_u64(time, PERF_LOOPS); - printk(" -> %llu cycles\n", (unsigned long long)time); - - printk(KERN_ALERT "prio tree search"); - - for (j = 0; j < NODES; j++) - prio_tree_insert(&root, nodes + j); - - time1 = get_cycles(); - - results = 0; - for (i = 0; i < SEARCH_LOOPS; i++) - for (j = 0; j < SEARCHES; j++) - results += search(queries[j], &root); - - time2 = get_cycles(); - time = time2 - time1; - - time = div_u64(time, SEARCH_LOOPS); - results = div_u64(results, SEARCH_LOOPS); - printk(" -> %llu cycles (%lu results)\n", - (unsigned long long)time, results); - - return -EAGAIN; /* Fail will directly unload the module */ -} - -static void prio_tree_test_exit(void) -{ - printk(KERN_ALERT "test exit\n"); -} - -module_init(prio_tree_test_init) -module_exit(prio_tree_test_exit) - -MODULE_LICENSE("GPL"); -MODULE_AUTHOR("Michel Lespinasse"); -MODULE_DESCRIPTION("Prio Tree test"); |