diff --git a/sys/kern/subr_pctrie.c b/sys/kern/subr_pctrie.c index a078f0587f37..16690c3521bf 100644 --- a/sys/kern/subr_pctrie.c +++ b/sys/kern/subr_pctrie.c @@ -1,1322 +1,1086 @@ /*- * SPDX-License-Identifier: BSD-2-Clause * * Copyright (c) 2013 EMC Corp. * Copyright (c) 2011 Jeffrey Roberson * Copyright (c) 2008 Mayur Shardul * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * */ /* * Path-compressed radix trie implementation. * * The implementation takes into account the following rationale: * - Size of the nodes should be as small as possible but still big enough * to avoid a large maximum depth for the trie. This is a balance * between the necessity to not wire too much physical memory for the nodes * and the necessity to avoid too much cache pollution during the trie * operations. * - There is not a huge bias toward the number of lookup operations over * the number of insert and remove operations. This basically implies * that optimizations supposedly helping one operation but hurting the * other might be carefully evaluated. * - On average not many nodes are expected to be fully populated, hence * level compression may just complicate things. */ #include #include "opt_ddb.h" #include #include #include #include #include #include /* smr.h depends on struct thread. */ #include #include #ifdef DDB #include #endif #if PCTRIE_WIDTH == 3 typedef uint8_t pn_popmap_t; #elif PCTRIE_WIDTH == 4 typedef uint16_t pn_popmap_t; #elif PCTRIE_WIDTH == 5 typedef uint32_t pn_popmap_t; #else #error Unsupported width #endif _Static_assert(sizeof(pn_popmap_t) <= sizeof(int), "pn_popmap_t too wide"); struct pctrie_node; typedef SMR_POINTER(struct pctrie_node *) smr_pctnode_t; struct pctrie_node { uint64_t pn_owner; /* Owner of record. */ pn_popmap_t pn_popmap; /* Valid children. */ uint8_t pn_clev; /* Level * WIDTH. */ + smr_pctnode_t pn_parent; /* Parent node. */ smr_pctnode_t pn_child[PCTRIE_COUNT]; /* Child nodes. */ }; /* * Map index to an array position for the children of node, */ static __inline int pctrie_slot(struct pctrie_node *node, uint64_t index) { return ((index >> node->pn_clev) & (PCTRIE_COUNT - 1)); } /* * Returns true if index does not belong to the specified node. Otherwise, * sets slot value, and returns false. */ static __inline bool pctrie_keybarr(struct pctrie_node *node, uint64_t index, int *slot) { index = (index - node->pn_owner) >> node->pn_clev; if (index >= PCTRIE_COUNT) return (true); *slot = index; return (false); } -/* - * Check radix node. - */ -static __inline void -pctrie_node_put(struct pctrie_node *node) -{ -#ifdef INVARIANTS - int slot; - - KASSERT(powerof2(node->pn_popmap), - ("pctrie_node_put: node %p has too many children %04x", node, - node->pn_popmap)); - for (slot = 0; slot < PCTRIE_COUNT; slot++) { - if ((node->pn_popmap & (1 << slot)) != 0) - continue; - KASSERT(smr_unserialized_load(&node->pn_child[slot], true) == - PCTRIE_NULL, - ("pctrie_node_put: node %p has a child", node)); - } -#endif -} - enum pctrie_access { PCTRIE_SMR, PCTRIE_LOCKED, PCTRIE_UNSERIALIZED }; /* * Fetch a node pointer from a slot. */ static __inline struct pctrie_node * pctrie_node_load(smr_pctnode_t *p, smr_t smr, enum pctrie_access access) { switch (access) { case PCTRIE_UNSERIALIZED: return (smr_unserialized_load(p, true)); case PCTRIE_LOCKED: return (smr_serialized_load(p, true)); case PCTRIE_SMR: return (smr_entered_load(p, smr)); } __assert_unreachable(); } static __inline void pctrie_node_store(smr_pctnode_t *p, void *v, enum pctrie_access access) { switch (access) { case PCTRIE_UNSERIALIZED: smr_unserialized_store(p, v, true); break; case PCTRIE_LOCKED: smr_serialized_store(p, v, true); break; case PCTRIE_SMR: panic("%s: Not supported in SMR section.", __func__); break; default: __assert_unreachable(); break; } } /* * Get the root address, cast to proper type for load/store. */ static __inline smr_pctnode_t * pctrie_root(struct pctrie *ptree) { return ((smr_pctnode_t *)&ptree->pt_root); } /* * Get the root node for a tree. */ static __inline struct pctrie_node * pctrie_root_load(struct pctrie *ptree, smr_t smr, enum pctrie_access access) { return (pctrie_node_load(pctrie_root(ptree), smr, access)); } +/* + * Get the child of a node. + */ +static __inline smr_pctnode_t * +pctrie_child(struct pctrie *ptree, struct pctrie_node *node, uint64_t index) +{ + return (node == NULL ? pctrie_root(ptree) : + &node->pn_child[pctrie_slot(node, index)]); +} + /* * Returns TRUE if the specified node is a leaf and FALSE otherwise. */ static __inline bool pctrie_isleaf(struct pctrie_node *node) { return (((uintptr_t)node & PCTRIE_ISLEAF) != 0); } /* * Returns val with leaf bit set. */ static __inline void * pctrie_toleaf(uint64_t *val) { return ((void *)((uintptr_t)val | PCTRIE_ISLEAF)); } /* * Returns the associated val extracted from node. */ static __inline uint64_t * pctrie_toval(struct pctrie_node *node) { return ((uint64_t *)((uintptr_t)node & ~PCTRIE_FLAGS)); } /* * Returns the associated pointer extracted from node and field offset. */ static __inline void * pctrie_toptr(struct pctrie_node *node, int keyoff) { return ((void *)(((uintptr_t)node & ~PCTRIE_FLAGS) - keyoff)); } +/* + * Make 'parent' a parent of 'child'. + */ +static __inline void +pctrie_setparent(struct pctrie_node *child, struct pctrie_node *parent) +{ + pctrie_node_store(&child->pn_parent, parent, PCTRIE_UNSERIALIZED); +} + +/* + * Return the parent of 'node'. + */ +static __inline struct pctrie_node * +pctrie_parent(struct pctrie_node *node) +{ + return (pctrie_node_load(&node->pn_parent, NULL, PCTRIE_UNSERIALIZED)); +} + /* * Make 'child' a child of 'node'. */ static __inline void pctrie_addnode(struct pctrie_node *node, uint64_t index, struct pctrie_node *child, enum pctrie_access access) { int slot; slot = pctrie_slot(node, index); pctrie_node_store(&node->pn_child[slot], child, access); node->pn_popmap ^= 1 << slot; KASSERT((node->pn_popmap & (1 << slot)) != 0, ("%s: bad popmap slot %d in node %p", __func__, slot, node)); } /* * pctrie node zone initializer. */ int pctrie_zone_init(void *mem, int size __unused, int flags __unused) { struct pctrie_node *node; node = mem; node->pn_popmap = 0; for (int i = 0; i < nitems(node->pn_child); i++) pctrie_node_store(&node->pn_child[i], PCTRIE_NULL, PCTRIE_UNSERIALIZED); return (0); } size_t pctrie_node_size(void) { return (sizeof(struct pctrie_node)); } -enum pctrie_insert_neighbor_mode { - PCTRIE_INSERT_NEIGHBOR_NONE, - PCTRIE_INSERT_NEIGHBOR_LT, - PCTRIE_INSERT_NEIGHBOR_GT, -}; - /* * Look for where to insert the key-value pair into the trie. Complete the * insertion if it replaces a null leaf. Return the insertion location if the * insertion needs to be completed by the caller; otherwise return NULL. * * If the key is already present in the trie, populate *found_out as if by * pctrie_lookup(). - * - * With mode PCTRIE_INSERT_NEIGHBOR_GT or PCTRIE_INSERT_NEIGHBOR_LT, set - * *neighbor_out to the lowest level node we encounter during the insert lookup - * that is a parent of the next greater or lesser entry. The value is not - * defined if the key was already present in the trie. - * - * Note that mode is expected to be a compile-time constant, and this procedure - * is expected to be inlined into callers with extraneous code optimized out. */ static __always_inline void * pctrie_insert_lookup_compound(struct pctrie *ptree, uint64_t *val, - uint64_t **found_out, struct pctrie_node **neighbor_out, - enum pctrie_insert_neighbor_mode mode) + struct pctrie_node **parent_out, uint64_t **found_out) { uint64_t index; struct pctrie_node *node, *parent; int slot; index = *val; /* * The owner of record for root is not really important because it * will never be used. */ node = pctrie_root_load(ptree, NULL, PCTRIE_LOCKED); parent = NULL; for (;;) { if (pctrie_isleaf(node)) { if (node == PCTRIE_NULL) { if (parent == NULL) pctrie_node_store(pctrie_root(ptree), pctrie_toleaf(val), PCTRIE_LOCKED); else pctrie_addnode(parent, index, pctrie_toleaf(val), PCTRIE_LOCKED); + *parent_out = parent; return (NULL); } if (*pctrie_toval(node) == index) { *found_out = pctrie_toval(node); + *parent_out = parent; return (NULL); } break; } if (pctrie_keybarr(node, index, &slot)) break; - /* - * Descend. If we're tracking the next neighbor and this node - * contains a neighboring entry in the right direction, record - * it. - */ - if (mode == PCTRIE_INSERT_NEIGHBOR_LT) { - if ((node->pn_popmap & ((1 << slot) - 1)) != 0) - *neighbor_out = node; - } else if (mode == PCTRIE_INSERT_NEIGHBOR_GT) { - if ((node->pn_popmap >> slot) > 1) - *neighbor_out = node; - } parent = node; node = pctrie_node_load(&node->pn_child[slot], NULL, PCTRIE_LOCKED); } - /* - * The caller will split this node. If we're tracking the next - * neighbor, record the old node if the old entry is in the right - * direction. - */ - if (mode == PCTRIE_INSERT_NEIGHBOR_LT) { - if (*pctrie_toval(node) < index) - *neighbor_out = node; - } else if (mode == PCTRIE_INSERT_NEIGHBOR_GT) { - if (*pctrie_toval(node) > index) - *neighbor_out = node; - } - /* * 'node' must be replaced in the tree with a new branch node, with * children 'node' and 'val'. Return the place that points to 'node' * now, and will point to to the new branching node later. */ + *parent_out = parent; return ((parent == NULL) ? pctrie_root(ptree): &parent->pn_child[slot]); } /* * Wrap pctrie_insert_lookup_compound to implement a strict insertion. Panic * if the key already exists, and do not look for neighboring entries. */ void * -pctrie_insert_lookup_strict(struct pctrie *ptree, uint64_t *val) +pctrie_insert_lookup_strict(struct pctrie *ptree, uint64_t *val, + struct pctrie_node **parent_out) { void *parentp; uint64_t *found; found = NULL; - parentp = pctrie_insert_lookup_compound(ptree, val, &found, NULL, - PCTRIE_INSERT_NEIGHBOR_NONE); + parentp = pctrie_insert_lookup_compound(ptree, val, parent_out, + &found); if (__predict_false(found != NULL)) panic("%s: key %jx is already present", __func__, (uintmax_t)*val); return (parentp); } /* * Wrap pctrie_insert_lookup_compound to implement find-or-insert. Do not look * for neighboring entries. */ void * pctrie_insert_lookup(struct pctrie *ptree, uint64_t *val, - uint64_t **found_out) -{ - *found_out = NULL; - return (pctrie_insert_lookup_compound(ptree, val, found_out, NULL, - PCTRIE_INSERT_NEIGHBOR_NONE)); -} - -/* - * Wrap pctrie_insert_lookup_compound to implement find or insert and find next - * greater entry. Find a subtree that contains the next entry greater than the - * newly-inserted or to-be-inserted entry. - */ -void * -pctrie_insert_lookup_gt(struct pctrie *ptree, uint64_t *val, - uint64_t **found_out, struct pctrie_node **neighbor_out) + struct pctrie_node **parent_out, uint64_t **found_out) { *found_out = NULL; - *neighbor_out = NULL; - return (pctrie_insert_lookup_compound(ptree, val, found_out, - neighbor_out, PCTRIE_INSERT_NEIGHBOR_GT)); + return (pctrie_insert_lookup_compound(ptree, val, parent_out, + found_out)); } /* - * Wrap pctrie_insert_lookup_compound to implement find or insert and find next - * lesser entry. Find a subtree that contains the next entry less than the - * newly-inserted or to-be-inserted entry. - */ -void * -pctrie_insert_lookup_lt(struct pctrie *ptree, uint64_t *val, - uint64_t **found_out, struct pctrie_node **neighbor_out) -{ - *found_out = NULL; - *neighbor_out = NULL; - return (pctrie_insert_lookup_compound(ptree, val, found_out, - neighbor_out, PCTRIE_INSERT_NEIGHBOR_LT)); -} - -/* - * Uses new node to insert key-value pair into the trie at given location. + * Inserts newly allocated node 'child' into trie at location 'parentp', with + * parent 'parent' and two children, 'val' and whatever non-NULL node or leaf + * was at 'parentp' to begin with. */ void -pctrie_insert_node(void *parentp, struct pctrie_node *parent, uint64_t *val) +pctrie_insert_node(uint64_t *val, struct pctrie_node *parent, void *parentp, + struct pctrie_node *child) { struct pctrie_node *node; uint64_t index, newind; /* - * Clear the last child pointer of the newly allocated parent. We want + * Clear the last child pointer of the newly allocated child. We want * to clear it after the final section has exited so lookup can not * return false negatives. It is done here because it will be * cache-cold in the dtor callback. */ - if (parent->pn_popmap != 0) { - pctrie_node_store(&parent->pn_child[ffs(parent->pn_popmap) - 1], + if (child->pn_popmap != 0) { + pctrie_node_store(&child->pn_child[ffs(child->pn_popmap) - 1], PCTRIE_NULL, PCTRIE_UNSERIALIZED); - parent->pn_popmap = 0; + child->pn_popmap = 0; } /* - * Recover the values of the two children of the new parent node. If + * Recover the values of the two children of the new child node. If * 'node' is not a leaf, this stores into 'newind' the 'owner' field, * which must be first in the node. */ index = *val; node = pctrie_node_load(parentp, NULL, PCTRIE_UNSERIALIZED); + pctrie_setparent(child, parent); + if (!pctrie_isleaf(node)) + pctrie_setparent(node, child); newind = *pctrie_toval(node); /* * From the highest-order bit where the indexes differ, * compute the highest level in the trie where they differ. Then, * compute the least index of this subtrie. */ _Static_assert(sizeof(long long) >= sizeof(uint64_t), "uint64 too wide"); _Static_assert(sizeof(uint64_t) * NBBY <= - (1 << (sizeof(parent->pn_clev) * NBBY)), "pn_clev too narrow"); - parent->pn_clev = rounddown(ilog2(index ^ newind), PCTRIE_WIDTH); - parent->pn_owner = PCTRIE_COUNT; - parent->pn_owner = index & -(parent->pn_owner << parent->pn_clev); + (1 << (sizeof(child->pn_clev) * NBBY)), "pn_clev too narrow"); + child->pn_clev = rounddown(ilog2(index ^ newind), PCTRIE_WIDTH); + child->pn_owner = PCTRIE_COUNT; + child->pn_owner = index & -(child->pn_owner << child->pn_clev); /* These writes are not yet visible due to ordering. */ - pctrie_addnode(parent, index, pctrie_toleaf(val), PCTRIE_UNSERIALIZED); - pctrie_addnode(parent, newind, node, PCTRIE_UNSERIALIZED); + pctrie_addnode(child, index, pctrie_toleaf(val), PCTRIE_UNSERIALIZED); + pctrie_addnode(child, newind, node, PCTRIE_UNSERIALIZED); /* Synchronize to make the above visible. */ - pctrie_node_store(parentp, parent, PCTRIE_LOCKED); + pctrie_node_store(parentp, child, PCTRIE_LOCKED); } /* * Return the value associated with the node, if the node is a leaf that matches * the index; otherwise NULL. */ static __always_inline uint64_t * pctrie_match_value(struct pctrie_node *node, uint64_t index) { uint64_t *m; if (!pctrie_isleaf(node) || (m = pctrie_toval(node)) == NULL || *m != index) m = NULL; return (m); } /* * Returns the value stored at the index. If the index is not present, * NULL is returned. */ static __always_inline uint64_t * _pctrie_lookup(struct pctrie *ptree, uint64_t index, smr_t smr, enum pctrie_access access) { struct pctrie_node *node; int slot; node = pctrie_root_load(ptree, smr, access); /* Seek a node that matches index. */ while (!pctrie_isleaf(node) && !pctrie_keybarr(node, index, &slot)) node = pctrie_node_load(&node->pn_child[slot], smr, access); return (pctrie_match_value(node, index)); } /* * Returns the value stored at the index, assuming access is externally * synchronized by a lock. * * If the index is not present, NULL is returned. */ uint64_t * pctrie_lookup(struct pctrie *ptree, uint64_t index) { return (_pctrie_lookup(ptree, index, NULL, PCTRIE_LOCKED)); } /* * Returns the value stored at the index without requiring an external lock. * * If the index is not present, NULL is returned. */ uint64_t * pctrie_lookup_unlocked(struct pctrie *ptree, uint64_t index, smr_t smr) { uint64_t *res; smr_enter(smr); res = _pctrie_lookup(ptree, index, smr, PCTRIE_SMR); smr_exit(smr); return (res); } /* - * Returns the last node examined in the search for the index, and updates the - * search path to that node. + * Returns the last node examined in the search for the index, and sets the + * parent of that node. */ static __always_inline struct pctrie_node * -_pctrie_iter_lookup_node(struct pctrie_iter *it, uint64_t index, smr_t smr, - enum pctrie_access access) +_pctrie_lookup_node(struct pctrie *ptree, struct pctrie_node *node, + uint64_t index, struct pctrie_node **parent_out, + smr_t smr, enum pctrie_access access) { - struct pctrie_node *node; + struct pctrie_node *parent; int slot; /* * Climb the search path to find the lowest node from which to start the * search for a value matching 'index'. */ - while (it->top != 0) { - node = it->path[it->top - 1]; + while (node != NULL) { KASSERT(!powerof2(node->pn_popmap), ("%s: freed node in iter path", __func__)); - if (!pctrie_keybarr(node, index, &slot)) { - node = pctrie_node_load( - &node->pn_child[slot], smr, access); + if (!pctrie_keybarr(node, index, &slot)) break; - } - --it->top; + node = pctrie_parent(node); + } + + if (node == NULL) { + parent = NULL; + node = pctrie_root_load(ptree, smr, access); + } else { + parent = node; + node = pctrie_node_load(&node->pn_child[slot], smr, access); } - if (it->top == 0) - node = pctrie_root_load(it->ptree, smr, access); /* Seek a node that matches index. */ while (!pctrie_isleaf(node) && !pctrie_keybarr(node, index, &slot)) { - KASSERT(it->top < nitems(it->path), - ("%s: path overflow in trie %p", __func__, it->ptree)); - it->path[it->top++] = node; + parent = node; node = pctrie_node_load(&node->pn_child[slot], smr, access); } + if (parent_out != NULL) + *parent_out = parent; return (node); } /* * Returns the value stored at a given index value, possibly NULL. */ static __always_inline uint64_t * _pctrie_iter_lookup(struct pctrie_iter *it, uint64_t index, smr_t smr, enum pctrie_access access) { struct pctrie_node *node; it->index = index; - node = _pctrie_iter_lookup_node(it, index, smr, access); + node = _pctrie_lookup_node(it->ptree, it->node, index, &it->node, + smr, access); return (pctrie_match_value(node, index)); } /* * Returns the value stored at a given index value, possibly NULL. */ uint64_t * pctrie_iter_lookup(struct pctrie_iter *it, uint64_t index) { return (_pctrie_iter_lookup(it, index, NULL, PCTRIE_LOCKED)); } /* * Insert the val in the trie, starting search with iterator. Return a pointer * to indicate where a new node must be allocated to complete insertion. * Assumes access is externally synchronized by a lock. */ void * pctrie_iter_insert_lookup(struct pctrie_iter *it, uint64_t *val) { struct pctrie_node *node; it->index = *val; - node = _pctrie_iter_lookup_node(it, *val, NULL, PCTRIE_LOCKED); + node = _pctrie_lookup_node(it->ptree, it->node, *val, &it->node, + NULL, PCTRIE_LOCKED); if (node == PCTRIE_NULL) { - if (it->top == 0) + if (it->node == NULL) pctrie_node_store(pctrie_root(it->ptree), pctrie_toleaf(val), PCTRIE_LOCKED); else - pctrie_addnode(it->path[it->top - 1], it->index, + pctrie_addnode(it->node, it->index, pctrie_toleaf(val), PCTRIE_LOCKED); return (NULL); } if (__predict_false(pctrie_match_value(node, it->index) != NULL)) panic("%s: key %jx is already present", __func__, (uintmax_t)it->index); /* * 'node' must be replaced in the tree with a new branch node, with * children 'node' and 'val'. Return the place that points to 'node' * now, and will point to to the new branching node later. */ - if (it->top == 0) - return (pctrie_root(it->ptree)); - node = it->path[it->top - 1]; - return (&node->pn_child[pctrie_slot(node, it->index)]); + return (pctrie_child(it->ptree, it->node, it->index)); } /* * Returns the value stored at a fixed offset from the current index value, * possibly NULL. */ static __always_inline uint64_t * _pctrie_iter_stride(struct pctrie_iter *it, int stride, smr_t smr, enum pctrie_access access) { uint64_t index = it->index + stride; /* Detect stride overflow. */ if ((stride > 0) != (index > it->index)) return (NULL); /* Detect crossing limit */ if ((index < it->limit) != (it->index < it->limit)) return (NULL); return (_pctrie_iter_lookup(it, index, smr, access)); } /* * Returns the value stored at a fixed offset from the current index value, * possibly NULL. */ uint64_t * pctrie_iter_stride(struct pctrie_iter *it, int stride) { return (_pctrie_iter_stride(it, stride, NULL, PCTRIE_LOCKED)); } /* * Returns the value stored at one more than the current index value, possibly * NULL, assuming access is externally synchronized by a lock. */ uint64_t * pctrie_iter_next(struct pctrie_iter *it) { return (_pctrie_iter_stride(it, 1, NULL, PCTRIE_LOCKED)); } /* * Returns the value stored at one less than the current index value, possibly * NULL, assuming access is externally synchronized by a lock. */ uint64_t * pctrie_iter_prev(struct pctrie_iter *it) { return (_pctrie_iter_stride(it, -1, NULL, PCTRIE_LOCKED)); } -/* - * Returns the value with the least index that is greater than or equal to the - * specified index, or NULL if there are no such values. - * - * Requires that access be externally synchronized by a lock. - */ -static __inline uint64_t * -pctrie_lookup_ge_node(struct pctrie_node *node, uint64_t index) -{ - struct pctrie_node *succ; - uint64_t *m; - int slot; - - /* - * Descend the trie as if performing an ordinary lookup for the - * specified value. However, unlike an ordinary lookup, as we descend - * the trie, we use "succ" to remember the last branching-off point, - * that is, the interior node under which the least value that is both - * outside our current path down the trie and greater than the specified - * index resides. (The node's popmap makes it fast and easy to - * recognize a branching-off point.) If our ordinary lookup fails to - * yield a value that is greater than or equal to the specified index, - * then we will exit this loop and perform a lookup starting from - * "succ". If "succ" is not NULL, then that lookup is guaranteed to - * succeed. - */ - succ = NULL; - for (;;) { - if (pctrie_isleaf(node)) { - if ((m = pctrie_toval(node)) != NULL && *m >= index) - return (m); - break; - } - if (pctrie_keybarr(node, index, &slot)) { - /* - * If all values in this subtree are > index, then the - * least value in this subtree is the answer. - */ - if (node->pn_owner > index) - succ = node; - break; - } - - /* - * Just in case the next search step leads to a subtree of all - * values < index, check popmap to see if a next bigger step, to - * a subtree of all pages with values > index, is available. If - * so, remember to restart the search here. - */ - if ((node->pn_popmap >> slot) > 1) - succ = node; - node = pctrie_node_load(&node->pn_child[slot], NULL, - PCTRIE_LOCKED); - } - - /* - * Restart the search from the last place visited in the subtree that - * included some values > index, if there was such a place. - */ - if (succ == NULL) - return (NULL); - if (succ != node) { - /* - * Take a step to the next bigger sibling of the node chosen - * last time. In that subtree, all values > index. - */ - slot = pctrie_slot(succ, index) + 1; - KASSERT((succ->pn_popmap >> slot) != 0, - ("%s: no popmap siblings past slot %d in node %p", - __func__, slot, succ)); - slot += ffs(succ->pn_popmap >> slot) - 1; - succ = pctrie_node_load(&succ->pn_child[slot], NULL, - PCTRIE_LOCKED); - } - - /* - * Find the value in the subtree rooted at "succ" with the least index. - */ - while (!pctrie_isleaf(succ)) { - KASSERT(succ->pn_popmap != 0, - ("%s: no popmap children in node %p", __func__, succ)); - slot = ffs(succ->pn_popmap) - 1; - succ = pctrie_node_load(&succ->pn_child[slot], NULL, - PCTRIE_LOCKED); - } - return (pctrie_toval(succ)); -} - -uint64_t * -pctrie_lookup_ge(struct pctrie *ptree, uint64_t index) -{ - return (pctrie_lookup_ge_node( - pctrie_root_load(ptree, NULL, PCTRIE_LOCKED), index)); -} - -uint64_t * -pctrie_subtree_lookup_gt(struct pctrie_node *node, uint64_t index) -{ - if (node == NULL || index + 1 == 0) - return (NULL); - return (pctrie_lookup_ge_node(node, index + 1)); -} - /* * Find first leaf >= index, and fill iter with the path to the parent of that * leaf. Return NULL if there is no such leaf less than limit. */ -uint64_t * -pctrie_iter_lookup_ge(struct pctrie_iter *it, uint64_t index) +static __inline uint64_t * +_pctrie_lookup_ge(struct pctrie *ptree, struct pctrie_node *node, + uint64_t index, struct pctrie_node **parent_out, uint64_t limit) { - struct pctrie_node *node; + struct pctrie_node *parent; uint64_t *m; int slot; /* Seek a node that matches index. */ - node = _pctrie_iter_lookup_node(it, index, NULL, PCTRIE_LOCKED); + node = _pctrie_lookup_node(ptree, node, index, &parent, + NULL, PCTRIE_LOCKED); /* * If no such node was found, and instead this path leads only to nodes * < index, back up to find a subtrie with the least value > index. */ if (node == PCTRIE_NULL || *pctrie_toval(node) < index) { /* Climb the path to find a node with a descendant > index. */ - while (it->top != 0) { - node = it->path[it->top - 1]; + for (node = parent; node != NULL; node = pctrie_parent(node)) { slot = pctrie_slot(node, index) + 1; if ((node->pn_popmap >> slot) != 0) break; - --it->top; } - if (it->top == 0) + if (node == NULL) { + if (parent_out != NULL) + *parent_out = NULL; return (NULL); + } /* Step to the least child with a descendant > index. */ slot += ffs(node->pn_popmap >> slot) - 1; + parent = node; node = pctrie_node_load(&node->pn_child[slot], NULL, PCTRIE_LOCKED); } /* Descend to the least leaf of the subtrie. */ while (!pctrie_isleaf(node)) { - if (it->limit != 0 && node->pn_owner >= it->limit) + if (limit != 0 && node->pn_owner >= limit) return (NULL); slot = ffs(node->pn_popmap) - 1; - KASSERT(it->top < nitems(it->path), - ("%s: path overflow in trie %p", __func__, it->ptree)); - it->path[it->top++] = node; + parent = node; node = pctrie_node_load(&node->pn_child[slot], NULL, PCTRIE_LOCKED); } + if (parent_out != NULL) + *parent_out = parent; m = pctrie_toval(node); - if (it->limit != 0 && *m >= it->limit) + if (limit != 0 && *m >= limit) return (NULL); - it->index = *m; + return (m); +} + +uint64_t * +pctrie_lookup_ge(struct pctrie *ptree, uint64_t index) +{ + return (_pctrie_lookup_ge(ptree, NULL, index, NULL, 0)); +} + +/* + * Find first leaf >= index, and fill iter with the path to the parent of that + * leaf. Return NULL if there is no such leaf less than limit. + */ +uint64_t * +pctrie_iter_lookup_ge(struct pctrie_iter *it, uint64_t index) +{ + uint64_t *m; + + m = _pctrie_lookup_ge(it->ptree, it->node, index, &it->node, it->limit); + if (m != NULL) + it->index = *m; return (m); } /* * Find the first leaf with value at least 'jump' greater than the previous * leaf. Return NULL if that value is >= limit. */ uint64_t * pctrie_iter_jump_ge(struct pctrie_iter *it, int64_t jump) { uint64_t index = it->index + jump; /* Detect jump overflow. */ if ((jump > 0) != (index > it->index)) return (NULL); if (it->limit != 0 && index >= it->limit) return (NULL); return (pctrie_iter_lookup_ge(it, index)); } -#ifdef INVARIANTS -void -pctrie_subtree_lookup_gt_assert(struct pctrie_node *node, uint64_t index, - struct pctrie *ptree, uint64_t *res) -{ - uint64_t *expected; - - if (index + 1 == 0) - expected = NULL; - else - expected = pctrie_lookup_ge(ptree, index + 1); - KASSERT(res == expected, - ("pctrie subtree lookup gt result different from root lookup: " - "ptree %p, index %ju, subtree %p, found %p, expected %p", ptree, - (uintmax_t)index, node, res, expected)); -} -#endif - /* - * Returns the value with the greatest index that is less than or equal to the - * specified index, or NULL if there are no such values. - * - * Requires that access be externally synchronized by a lock. + * Find first leaf <= index, and fill iter with the path to the parent of that + * leaf. Return NULL if there is no such leaf greater than limit. */ static __inline uint64_t * -pctrie_lookup_le_node(struct pctrie_node *node, uint64_t index) +_pctrie_lookup_le(struct pctrie *ptree, struct pctrie_node *node, + uint64_t index, struct pctrie_node **parent_out, uint64_t limit) { - struct pctrie_node *pred; + struct pctrie_node *parent; uint64_t *m; int slot; + /* Seek a node that matches index. */ + node = _pctrie_lookup_node(ptree, node, index, &parent, NULL, + PCTRIE_LOCKED); + /* - * Mirror the implementation of pctrie_lookup_ge_node, described above. + * If no such node was found, and instead this path leads only to nodes + * > index, back up to find a subtrie with the greatest value < index. */ - pred = NULL; - for (;;) { - if (pctrie_isleaf(node)) { - if ((m = pctrie_toval(node)) != NULL && *m <= index) - return (m); - break; + if (node == PCTRIE_NULL || *pctrie_toval(node) > index) { + /* Climb the path to find a node with a descendant < index. */ + for (node = parent; node != NULL; node = pctrie_parent(node)) { + slot = pctrie_slot(node, index); + if ((node->pn_popmap & ((1 << slot) - 1)) != 0) + break; } - if (pctrie_keybarr(node, index, &slot)) { - if (node->pn_owner < index) - pred = node; - break; + if (node == NULL) { + if (parent_out != NULL) + *parent_out = NULL; + return (NULL); } - if ((node->pn_popmap & ((1 << slot) - 1)) != 0) - pred = node; + + /* Step to the greatest child with a descendant < index. */ + slot = ilog2(node->pn_popmap & ((1 << slot) - 1)); + parent = node; node = pctrie_node_load(&node->pn_child[slot], NULL, PCTRIE_LOCKED); } - if (pred == NULL) - return (NULL); - if (pred != node) { - slot = pctrie_slot(pred, index); - KASSERT((pred->pn_popmap & ((1 << slot) - 1)) != 0, - ("%s: no popmap siblings before slot %d in node %p", - __func__, slot, pred)); - slot = ilog2(pred->pn_popmap & ((1 << slot) - 1)); - pred = pctrie_node_load(&pred->pn_child[slot], NULL, - PCTRIE_LOCKED); - } - while (!pctrie_isleaf(pred)) { - KASSERT(pred->pn_popmap != 0, - ("%s: no popmap children in node %p", __func__, pred)); - slot = ilog2(pred->pn_popmap); - pred = pctrie_node_load(&pred->pn_child[slot], NULL, + /* Descend to the greatest leaf of the subtrie. */ + while (!pctrie_isleaf(node)) { + if (limit != 0 && limit >= node->pn_owner + + ((uint64_t)PCTRIE_COUNT << node->pn_clev) - 1) + return (NULL); + slot = ilog2(node->pn_popmap); + parent = node; + node = pctrie_node_load(&node->pn_child[slot], NULL, PCTRIE_LOCKED); } - return (pctrie_toval(pred)); + if (parent_out != NULL) + *parent_out = parent; + m = pctrie_toval(node); + if (limit != 0 && *m <= limit) + return (NULL); + return (m); } uint64_t * pctrie_lookup_le(struct pctrie *ptree, uint64_t index) { - return (pctrie_lookup_le_node( - pctrie_root_load(ptree, NULL, PCTRIE_LOCKED), index)); + return (_pctrie_lookup_le(ptree, NULL, index, NULL, 0)); } uint64_t * -pctrie_subtree_lookup_lt(struct pctrie_node *node, uint64_t index) +pctrie_subtree_lookup_lt(struct pctrie *ptree, struct pctrie_node *node, + uint64_t index) { - if (node == NULL || index == 0) + if (index == 0) return (NULL); - return (pctrie_lookup_le_node(node, index - 1)); + return (_pctrie_lookup_le(ptree, node, index - 1, NULL, 0)); } /* * Find first leaf <= index, and fill iter with the path to the parent of that * leaf. Return NULL if there is no such leaf greater than limit. */ uint64_t * pctrie_iter_lookup_le(struct pctrie_iter *it, uint64_t index) { - struct pctrie_node *node; uint64_t *m; - int slot; - - /* Seek a node that matches index. */ - node = _pctrie_iter_lookup_node(it, index, NULL, PCTRIE_LOCKED); - /* - * If no such node was found, and instead this path leads only to nodes - * > index, back up to find a subtrie with the greatest value < index. - */ - if (node == PCTRIE_NULL || *pctrie_toval(node) > index) { - /* Climb the path to find a node with a descendant < index. */ - while (it->top != 0) { - node = it->path[it->top - 1]; - slot = pctrie_slot(node, index); - if ((node->pn_popmap & ((1 << slot) - 1)) != 0) - break; - --it->top; - } - if (it->top == 0) - return (NULL); - - /* Step to the greatest child with a descendant < index. */ - slot = ilog2(node->pn_popmap & ((1 << slot) - 1)); - node = pctrie_node_load(&node->pn_child[slot], NULL, - PCTRIE_LOCKED); - } - /* Descend to the greatest leaf of the subtrie. */ - while (!pctrie_isleaf(node)) { - if (it->limit != 0 && it->limit >= - node->pn_owner + (PCTRIE_COUNT << node->pn_clev) - 1) - return (NULL); - slot = ilog2(node->pn_popmap); - KASSERT(it->top < nitems(it->path), - ("%s: path overflow in trie %p", __func__, it->ptree)); - it->path[it->top++] = node; - node = pctrie_node_load(&node->pn_child[slot], NULL, - PCTRIE_LOCKED); - } - m = pctrie_toval(node); - if (it->limit != 0 && *m <= it->limit) - return (NULL); - it->index = *m; + m = _pctrie_lookup_le(it->ptree, it->node, index, &it->node, it->limit); + if (m != NULL) + it->index = *m; return (m); } /* * Find the first leaf with value at most 'jump' less than the previous * leaf. Return NULL if that value is <= limit. */ uint64_t * pctrie_iter_jump_le(struct pctrie_iter *it, int64_t jump) { uint64_t index = it->index - jump; /* Detect jump overflow. */ if ((jump > 0) != (index < it->index)) return (NULL); if (it->limit != 0 && index <= it->limit) return (NULL); return (pctrie_iter_lookup_le(it, index)); } -#ifdef INVARIANTS -void -pctrie_subtree_lookup_lt_assert(struct pctrie_node *node, uint64_t index, - struct pctrie *ptree, uint64_t *res) -{ - uint64_t *expected; - - if (index == 0) - expected = NULL; - else - expected = pctrie_lookup_le(ptree, index - 1); - KASSERT(res == expected, - ("pctrie subtree lookup lt result different from root lookup: " - "ptree %p, index %ju, subtree %p, found %p, expected %p", ptree, - (uintmax_t)index, node, res, expected)); -} -#endif - -static void -pctrie_remove(struct pctrie *ptree, uint64_t index, struct pctrie_node *parent, - struct pctrie_node *node, struct pctrie_node **freenode) +/* + * If 'child', a leaf and a child of 'parent', is not NULL and has key 'index', + * then remove it from the pctrie and return its value. If doing so produces an + * internal node with only one child, purge it from the pctrie and save it in + * *freenode for later disposal. + */ +static uint64_t * +pctrie_remove(struct pctrie *ptree, struct pctrie_node *node, uint64_t index, + struct pctrie_node *child, struct pctrie_node **freenode) { - struct pctrie_node *child; + uint64_t *m; int slot; + *freenode = NULL; + m = pctrie_match_value(child, index); + if (m == NULL) + return (m); if (node == NULL) { pctrie_node_store(pctrie_root(ptree), PCTRIE_NULL, PCTRIE_LOCKED); - return; + return (m); } slot = pctrie_slot(node, index); KASSERT((node->pn_popmap & (1 << slot)) != 0, ("%s: bad popmap slot %d in node %p", __func__, slot, node)); node->pn_popmap ^= 1 << slot; pctrie_node_store(&node->pn_child[slot], PCTRIE_NULL, PCTRIE_LOCKED); if (!powerof2(node->pn_popmap)) - return; + return (m); KASSERT(node->pn_popmap != 0, ("%s: bad popmap all zeroes", __func__)); slot = ffs(node->pn_popmap) - 1; child = pctrie_node_load(&node->pn_child[slot], NULL, PCTRIE_LOCKED); KASSERT(child != PCTRIE_NULL, ("%s: bad popmap slot %d in node %p", __func__, slot, node)); - if (parent == NULL) - pctrie_node_store(pctrie_root(ptree), child, PCTRIE_LOCKED); - else { - slot = pctrie_slot(parent, index); - KASSERT(node == - pctrie_node_load(&parent->pn_child[slot], NULL, - PCTRIE_LOCKED), ("%s: invalid child value", __func__)); - pctrie_node_store(&parent->pn_child[slot], child, - PCTRIE_LOCKED); - } - /* - * The child is still valid and we can not zero the - * pointer until all SMR references are gone. - */ - pctrie_node_put(node); *freenode = node; + node = pctrie_parent(node); + if (!pctrie_isleaf(child)) + pctrie_setparent(child, node); + pctrie_node_store(pctrie_child(ptree, node, index), child, + PCTRIE_LOCKED); + return (m); } /* * Remove the specified index from the tree, and return the value stored at * that index. If the index is not present, return NULL. */ uint64_t * pctrie_remove_lookup(struct pctrie *ptree, uint64_t index, struct pctrie_node **freenode) { - struct pctrie_node *child, *node, *parent; - uint64_t *m; + struct pctrie_node *child, *node; int slot; - DEBUG_POISON_POINTER(parent); - *freenode = node = NULL; + node = NULL; child = pctrie_root_load(ptree, NULL, PCTRIE_LOCKED); while (!pctrie_isleaf(child)) { - parent = node; node = child; slot = pctrie_slot(node, index); child = pctrie_node_load(&node->pn_child[slot], NULL, PCTRIE_LOCKED); } - m = pctrie_match_value(child, index); - if (m != NULL) - pctrie_remove(ptree, index, parent, node, freenode); - return (m); + return (pctrie_remove(ptree, node, index, child, freenode)); } /* * Remove from the trie the leaf last chosen by the iterator, and * adjust the path if it's last member is to be freed. */ uint64_t * pctrie_iter_remove(struct pctrie_iter *it, struct pctrie_node **freenode) { - struct pctrie_node *child, *node, *parent; + struct pctrie_node *child; uint64_t *m; - int slot; - DEBUG_POISON_POINTER(parent); - *freenode = NULL; - if (it->top >= 1) { - parent = (it->top >= 2) ? it->path[it->top - 2] : NULL; - node = it->path[it->top - 1]; - slot = pctrie_slot(node, it->index); - child = pctrie_node_load(&node->pn_child[slot], NULL, - PCTRIE_LOCKED); - } else { - node = NULL; - child = pctrie_root_load(it->ptree, NULL, PCTRIE_LOCKED); - } - m = pctrie_match_value(child, it->index); - if (m != NULL) - pctrie_remove(it->ptree, it->index, parent, node, freenode); + child = pctrie_node_load(pctrie_child(it->ptree, it->node, it->index), + NULL, PCTRIE_LOCKED); + m = pctrie_remove(it->ptree, it->node, it->index, child, freenode); if (*freenode != NULL) - --it->top; + it->node = pctrie_parent(it->node); return (m); } /* * Return the current leaf, assuming access is externally synchronized by a * lock. */ uint64_t * pctrie_iter_value(struct pctrie_iter *it) { struct pctrie_node *node; - int slot; - if (it->top == 0) - node = pctrie_root_load(it->ptree, NULL, - PCTRIE_LOCKED); - else { - node = it->path[it->top - 1]; - slot = pctrie_slot(node, it->index); - node = pctrie_node_load(&node->pn_child[slot], NULL, - PCTRIE_LOCKED); - } + node = pctrie_node_load(pctrie_child(it->ptree, it->node, it->index), + NULL, PCTRIE_LOCKED); return (pctrie_toval(node)); } /* - * Walk the subtrie rooted at *pnode in order, invoking callback on leaves and - * using the leftmost child pointer for path reversal, until an interior node - * is stripped of all children, and returned for deallocation, with *pnode left - * pointing to the parent of that node. + * Walk the subtrie rooted at *pnode in order, invoking callback on leaves, + * until an interior node is stripped of all children, and returned for + * deallocation, with *pnode left pointing to the parent of that node. */ static __always_inline struct pctrie_node * pctrie_reclaim_prune(struct pctrie_node **pnode, struct pctrie_node *parent, pctrie_cb_t callback, int keyoff, void *arg) { struct pctrie_node *child, *node; int slot; node = *pnode; while (node->pn_popmap != 0) { slot = ffs(node->pn_popmap) - 1; node->pn_popmap ^= 1 << slot; child = pctrie_node_load(&node->pn_child[slot], NULL, PCTRIE_UNSERIALIZED); pctrie_node_store(&node->pn_child[slot], PCTRIE_NULL, PCTRIE_UNSERIALIZED); if (pctrie_isleaf(child)) { if (callback != NULL) callback(pctrie_toptr(child, keyoff), arg); continue; } /* Climb one level down the trie. */ - pctrie_node_store(&node->pn_child[0], parent, - PCTRIE_UNSERIALIZED); parent = node; node = child; } *pnode = parent; return (node); } /* * Recover the node parent from its first child and continue pruning. */ static __always_inline struct pctrie_node * pctrie_reclaim_resume_compound(struct pctrie_node **pnode, pctrie_cb_t callback, int keyoff, void *arg) { - struct pctrie_node *parent, *node; - - node = *pnode; - if (node == NULL) + if (*pnode == NULL) return (NULL); /* Climb one level up the trie. */ - parent = pctrie_node_load(&node->pn_child[0], NULL, - PCTRIE_UNSERIALIZED); - pctrie_node_store(&node->pn_child[0], PCTRIE_NULL, PCTRIE_UNSERIALIZED); - return (pctrie_reclaim_prune(pnode, parent, callback, keyoff, arg)); + return (pctrie_reclaim_prune(pnode, pctrie_parent(*pnode), callback, + keyoff, arg)); } /* * Find the trie root, and start pruning with a NULL parent. */ static __always_inline struct pctrie_node * pctrie_reclaim_begin_compound(struct pctrie_node **pnode, struct pctrie *ptree, pctrie_cb_t callback, int keyoff, void *arg) { struct pctrie_node *node; node = pctrie_root_load(ptree, NULL, PCTRIE_UNSERIALIZED); pctrie_node_store(pctrie_root(ptree), PCTRIE_NULL, PCTRIE_UNSERIALIZED); if (pctrie_isleaf(node)) { if (callback != NULL && node != PCTRIE_NULL) callback(pctrie_toptr(node, keyoff), arg); return (NULL); } *pnode = node; return (pctrie_reclaim_prune(pnode, NULL, callback, keyoff, arg)); } struct pctrie_node * pctrie_reclaim_resume(struct pctrie_node **pnode) { return (pctrie_reclaim_resume_compound(pnode, NULL, 0, NULL)); } struct pctrie_node * pctrie_reclaim_begin(struct pctrie_node **pnode, struct pctrie *ptree) { return (pctrie_reclaim_begin_compound(pnode, ptree, NULL, 0, NULL)); } struct pctrie_node * pctrie_reclaim_resume_cb(struct pctrie_node **pnode, pctrie_cb_t callback, int keyoff, void *arg) { return (pctrie_reclaim_resume_compound(pnode, callback, keyoff, arg)); } struct pctrie_node * pctrie_reclaim_begin_cb(struct pctrie_node **pnode, struct pctrie *ptree, pctrie_cb_t callback, int keyoff, void *arg) { return (pctrie_reclaim_begin_compound(pnode, ptree, callback, keyoff, arg)); } /* * Replace an existing value in the trie with another one. * Panics if there is not an old value in the trie at the new value's index. */ uint64_t * pctrie_replace(struct pctrie *ptree, uint64_t *newval) { struct pctrie_node *leaf, *parent, *node; uint64_t *m; uint64_t index; int slot; leaf = pctrie_toleaf(newval); index = *newval; node = pctrie_root_load(ptree, NULL, PCTRIE_LOCKED); parent = NULL; for (;;) { if (pctrie_isleaf(node)) { if ((m = pctrie_toval(node)) != NULL && *m == index) { if (parent == NULL) pctrie_node_store(pctrie_root(ptree), leaf, PCTRIE_LOCKED); else pctrie_node_store( &parent->pn_child[slot], leaf, PCTRIE_LOCKED); return (m); } break; } if (pctrie_keybarr(node, index, &slot)) break; parent = node; node = pctrie_node_load(&node->pn_child[slot], NULL, PCTRIE_LOCKED); } panic("%s: original replacing value not found", __func__); } #ifdef DDB /* * Show details about the given node. */ DB_SHOW_COMMAND(pctrienode, db_show_pctrienode) { struct pctrie_node *node, *tmp; int slot; pn_popmap_t popmap; if (!have_addr) return; node = (struct pctrie_node *)addr; db_printf("node %p, owner %jx, children popmap %04x, level %u:\n", (void *)node, (uintmax_t)node->pn_owner, node->pn_popmap, node->pn_clev / PCTRIE_WIDTH); for (popmap = node->pn_popmap; popmap != 0; popmap ^= 1 << slot) { slot = ffs(popmap) - 1; tmp = pctrie_node_load(&node->pn_child[slot], NULL, PCTRIE_UNSERIALIZED); db_printf("slot: %d, val: %p, value: %p, clev: %d\n", slot, (void *)tmp, pctrie_isleaf(tmp) ? pctrie_toval(tmp) : NULL, node->pn_clev / PCTRIE_WIDTH); } } #endif /* DDB */ diff --git a/sys/sys/pctrie.h b/sys/sys/pctrie.h index 8556f08561b9..196449e663d3 100644 --- a/sys/sys/pctrie.h +++ b/sys/sys/pctrie.h @@ -1,481 +1,435 @@ /*- * SPDX-License-Identifier: BSD-2-Clause * * Copyright (c) 2013 EMC Corp. * Copyright (c) 2011 Jeffrey Roberson * Copyright (c) 2008 Mayur Shardul * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ #ifndef _SYS_PCTRIE_H_ #define _SYS_PCTRIE_H_ #include #include +struct pctrie_iter { + struct pctrie *ptree; + struct pctrie_node *node; + uint64_t index; + uint64_t limit; +}; + +static __inline void +pctrie_iter_reset(struct pctrie_iter *it) +{ + it->node = NULL; +} + +static __inline void +pctrie_iter_init(struct pctrie_iter *it, struct pctrie *ptree) +{ + it->ptree = ptree; + it->node = NULL; + it->limit = 0; +} + +static __inline void +pctrie_iter_limit_init(struct pctrie_iter *it, struct pctrie *ptree, + uint64_t limit) +{ + pctrie_iter_init(it, ptree); + it->limit = limit; +} + #ifdef _KERNEL typedef void (*pctrie_cb_t)(void *ptr, void *arg); #define PCTRIE_DEFINE_SMR(name, type, field, allocfn, freefn, smr) \ PCTRIE_DEFINE(name, type, field, allocfn, freefn) \ \ static __inline struct type * \ name##_PCTRIE_LOOKUP_UNLOCKED(struct pctrie *ptree, uint64_t key) \ { \ \ return name##_PCTRIE_VAL2PTR(pctrie_lookup_unlocked(ptree, \ key, (smr))); \ } \ -#ifdef INVARIANTS -void pctrie_subtree_lookup_gt_assert(struct pctrie_node *node, - uint64_t key, struct pctrie *ptree, uint64_t *res); -void pctrie_subtree_lookup_lt_assert(struct pctrie_node *node, - uint64_t key, struct pctrie *ptree, uint64_t *res); -#else -#define pctrie_subtree_lookup_gt_assert(node, key, ptree, res) -#define pctrie_subtree_lookup_lt_assert(node, key, ptree, res) -#endif - #define PCTRIE_DEFINE(name, type, field, allocfn, freefn) \ \ CTASSERT(sizeof(((struct type *)0)->field) == sizeof(uint64_t)); \ /* \ * XXX This assert protects flag bits, it does not enforce natural \ * alignment. 32bit architectures do not naturally align 64bit fields. \ */ \ CTASSERT((__offsetof(struct type, field) & (sizeof(uint32_t) - 1)) == 0); \ \ static __inline struct type * \ name##_PCTRIE_VAL2PTR(uint64_t *val) \ { \ \ if (val == NULL) \ return (NULL); \ return (struct type *) \ ((uintptr_t)val - __offsetof(struct type, field)); \ } \ \ static __inline uint64_t * \ name##_PCTRIE_PTR2VAL(struct type *ptr) \ { \ \ return &ptr->field; \ } \ \ static __inline __unused int \ -name##_PCTRIE_INSERT_BASE(struct pctrie *ptree, void *parentp, \ - uint64_t *val, uint64_t *found, struct type **found_out) \ +name##_PCTRIE_INSERT_BASE(struct pctrie *ptree, uint64_t *val, \ + struct pctrie_node *parent, void *parentp, \ + uint64_t *found, struct type **found_out) \ { \ - struct pctrie_node *parent; \ + struct pctrie_node *child; \ \ if (__predict_false(found != NULL)) { \ *found_out = name##_PCTRIE_VAL2PTR(found); \ return (EEXIST); \ } \ if (parentp != NULL) { \ - parent = allocfn(ptree); \ - if (__predict_false(parent == NULL)) { \ + child = allocfn(ptree); \ + if (__predict_false(child == NULL)) { \ if (found_out != NULL) \ *found_out = NULL; \ return (ENOMEM); \ } \ - pctrie_insert_node(parentp, parent, val); \ + pctrie_insert_node(val, parent, parentp, child); \ } \ return (0); \ } \ \ static __inline __unused int \ name##_PCTRIE_INSERT(struct pctrie *ptree, struct type *ptr) \ { \ void *parentp; \ + struct pctrie_node *parent; \ uint64_t *val = name##_PCTRIE_PTR2VAL(ptr); \ \ - parentp = pctrie_insert_lookup_strict(ptree, val); \ - return (name##_PCTRIE_INSERT_BASE(ptree, parentp, val, \ + parentp = pctrie_insert_lookup_strict(ptree, val, &parent); \ + return (name##_PCTRIE_INSERT_BASE(ptree, val, parent, parentp, \ NULL, NULL)); \ } \ \ static __inline __unused int \ name##_PCTRIE_FIND_OR_INSERT(struct pctrie *ptree, struct type *ptr, \ struct type **found_out_opt) \ { \ void *parentp; \ + struct pctrie_node *parent; \ uint64_t *val = name##_PCTRIE_PTR2VAL(ptr); \ uint64_t *found; \ \ - parentp = pctrie_insert_lookup(ptree, val, &found); \ - return (name##_PCTRIE_INSERT_BASE(ptree, parentp, val, \ + parentp = pctrie_insert_lookup(ptree, val, &parent, &found); \ + return (name##_PCTRIE_INSERT_BASE(ptree, val, parent, parentp, \ found, found_out_opt)); \ } \ \ static __inline __unused int \ -name##_PCTRIE_INSERT_LOOKUP_GE(struct pctrie *ptree, struct type *ptr, \ +name##_PCTRIE_INSERT_LOOKUP_LE(struct pctrie *ptree, struct type *ptr, \ struct type **found_out) \ { \ - struct pctrie_node *neighbor; \ + struct pctrie_node *parent; \ void *parentp; \ uint64_t *val = name##_PCTRIE_PTR2VAL(ptr); \ uint64_t *found; \ int retval; \ \ - parentp = pctrie_insert_lookup_gt(ptree, val, &found, \ - &neighbor); \ - retval = name##_PCTRIE_INSERT_BASE(ptree, parentp, val, \ + parentp = pctrie_insert_lookup(ptree, val, &parent, &found); \ + retval = name##_PCTRIE_INSERT_BASE(ptree, val, parent, parentp, \ found, found_out); \ if (retval != 0) \ return (retval); \ - found = pctrie_subtree_lookup_gt(neighbor, *val); \ + found = pctrie_subtree_lookup_lt(ptree, parent, *val); \ *found_out = name##_PCTRIE_VAL2PTR(found); \ - pctrie_subtree_lookup_gt_assert(neighbor, *val, ptree, found); \ return (0); \ } \ \ static __inline __unused int \ -name##_PCTRIE_INSERT_LOOKUP_LE(struct pctrie *ptree, struct type *ptr, \ - struct type **found_out) \ +name##_PCTRIE_ITER_INSERT(struct pctrie_iter *it, struct type *ptr) \ { \ - struct pctrie_node *neighbor; \ void *parentp; \ uint64_t *val = name##_PCTRIE_PTR2VAL(ptr); \ - uint64_t *found; \ - int retval; \ \ - parentp = pctrie_insert_lookup_lt(ptree, val, &found, \ - &neighbor); \ - retval = name##_PCTRIE_INSERT_BASE(ptree, parentp, val, \ - found, found_out); \ - if (retval != 0) \ - return (retval); \ - found = pctrie_subtree_lookup_lt(neighbor, *val); \ - *found_out = name##_PCTRIE_VAL2PTR(found); \ - pctrie_subtree_lookup_lt_assert(neighbor, *val, ptree, found); \ - return (0); \ + parentp = pctrie_iter_insert_lookup(it, val); \ + return (name##_PCTRIE_INSERT_BASE(it->ptree, val, it->node, \ + parentp, NULL, NULL)); \ } \ \ static __inline __unused struct type * \ name##_PCTRIE_LOOKUP(struct pctrie *ptree, uint64_t key) \ { \ \ return name##_PCTRIE_VAL2PTR(pctrie_lookup(ptree, key)); \ } \ \ static __inline __unused struct type * \ name##_PCTRIE_LOOKUP_LE(struct pctrie *ptree, uint64_t key) \ { \ \ return name##_PCTRIE_VAL2PTR(pctrie_lookup_le(ptree, key)); \ } \ \ static __inline __unused struct type * \ name##_PCTRIE_LOOKUP_GE(struct pctrie *ptree, uint64_t key) \ { \ \ return name##_PCTRIE_VAL2PTR(pctrie_lookup_ge(ptree, key)); \ } \ \ static __inline __unused void \ name##_PCTRIE_RECLAIM(struct pctrie *ptree) \ { \ struct pctrie_node *freenode, *node; \ \ for (freenode = pctrie_reclaim_begin(&node, ptree); \ freenode != NULL; \ freenode = pctrie_reclaim_resume(&node)) \ freefn(ptree, freenode); \ } \ \ /* \ * While reclaiming all internal trie nodes, invoke callback(leaf, arg) \ * on every leaf in the trie, in order. \ */ \ static __inline __unused void \ name##_PCTRIE_RECLAIM_CALLBACK(struct pctrie *ptree, \ void (*typed_cb)(struct type *, void *), void *arg) \ { \ struct pctrie_node *freenode, *node; \ pctrie_cb_t callback = (pctrie_cb_t)typed_cb; \ \ for (freenode = pctrie_reclaim_begin_cb(&node, ptree, \ callback, __offsetof(struct type, field), arg); \ freenode != NULL; \ freenode = pctrie_reclaim_resume_cb(&node, \ callback, __offsetof(struct type, field), arg)) \ freefn(ptree, freenode); \ } \ \ -static __inline __unused int \ -name##_PCTRIE_ITER_INSERT(struct pctrie_iter *it, struct type *ptr) \ -{ \ - struct pctrie_node *parent; \ - void *parentp; \ - uint64_t *val = name##_PCTRIE_PTR2VAL(ptr); \ - \ - parentp = pctrie_iter_insert_lookup(it, val); \ - if (parentp == NULL) \ - return (0); \ - parent = allocfn(it->ptree); \ - if (__predict_false(parent == NULL)) \ - return (ENOMEM); \ - pctrie_insert_node(parentp, parent, val); \ - it->path[it->top++] = parent; \ - return (0); \ -} \ - \ static __inline __unused struct type * \ name##_PCTRIE_ITER_LOOKUP(struct pctrie_iter *it, uint64_t index) \ { \ return name##_PCTRIE_VAL2PTR(pctrie_iter_lookup(it, index)); \ } \ \ static __inline __unused struct type * \ name##_PCTRIE_ITER_STRIDE(struct pctrie_iter *it, int stride) \ { \ return name##_PCTRIE_VAL2PTR(pctrie_iter_stride(it, stride)); \ } \ \ static __inline __unused struct type * \ name##_PCTRIE_ITER_NEXT(struct pctrie_iter *it) \ { \ return name##_PCTRIE_VAL2PTR(pctrie_iter_next(it)); \ } \ \ static __inline __unused struct type * \ name##_PCTRIE_ITER_PREV(struct pctrie_iter *it) \ { \ return name##_PCTRIE_VAL2PTR(pctrie_iter_prev(it)); \ } \ \ static __inline __unused struct type * \ name##_PCTRIE_ITER_VALUE(struct pctrie_iter *it) \ { \ return name##_PCTRIE_VAL2PTR(pctrie_iter_value(it)); \ } \ \ static __inline __unused struct type * \ name##_PCTRIE_ITER_LOOKUP_GE(struct pctrie_iter *it, uint64_t index) \ { \ return name##_PCTRIE_VAL2PTR(pctrie_iter_lookup_ge(it, index)); \ } \ \ static __inline __unused struct type * \ name##_PCTRIE_ITER_JUMP_GE(struct pctrie_iter *it, int64_t jump) \ { \ return name##_PCTRIE_VAL2PTR(pctrie_iter_jump_ge(it, jump)); \ } \ \ static __inline __unused struct type * \ name##_PCTRIE_ITER_STEP_GE(struct pctrie_iter *it) \ { \ return name##_PCTRIE_VAL2PTR(pctrie_iter_jump_ge(it, 1)); \ } \ \ static __inline __unused struct type * \ name##_PCTRIE_ITER_LOOKUP_LE(struct pctrie_iter *it, uint64_t index) \ { \ return name##_PCTRIE_VAL2PTR(pctrie_iter_lookup_le(it, index)); \ } \ \ static __inline __unused struct type * \ name##_PCTRIE_ITER_JUMP_LE(struct pctrie_iter *it, int64_t jump) \ { \ return name##_PCTRIE_VAL2PTR(pctrie_iter_jump_le(it, jump)); \ } \ \ static __inline __unused struct type * \ name##_PCTRIE_ITER_STEP_LE(struct pctrie_iter *it) \ { \ return name##_PCTRIE_VAL2PTR(pctrie_iter_jump_le(it, 1)); \ } \ \ static __inline __unused void \ name##_PCTRIE_REMOVE_BASE(struct pctrie *ptree, \ struct pctrie_node *freenode) \ { \ if (freenode != NULL) \ freefn(ptree, freenode); \ } \ \ static __inline __unused void \ name##_PCTRIE_ITER_REMOVE(struct pctrie_iter *it) \ { \ uint64_t *val; \ struct pctrie_node *freenode; \ \ val = pctrie_iter_remove(it, &freenode); \ if (val == NULL) \ panic("%s: key not found", __func__); \ name##_PCTRIE_REMOVE_BASE(it->ptree, freenode); \ } \ \ static __inline __unused struct type * \ name##_PCTRIE_REPLACE(struct pctrie *ptree, struct type *ptr) \ { \ \ return name##_PCTRIE_VAL2PTR( \ pctrie_replace(ptree, name##_PCTRIE_PTR2VAL(ptr))); \ } \ \ static __inline __unused void \ name##_PCTRIE_REMOVE(struct pctrie *ptree, uint64_t key) \ { \ uint64_t *val; \ struct pctrie_node *freenode; \ \ val = pctrie_remove_lookup(ptree, key, &freenode); \ if (val == NULL) \ panic("%s: key not found", __func__); \ name##_PCTRIE_REMOVE_BASE(ptree, freenode); \ } \ \ static __inline __unused struct type * \ name##_PCTRIE_REMOVE_LOOKUP(struct pctrie *ptree, uint64_t key) \ { \ uint64_t *val; \ struct pctrie_node *freenode; \ \ val = pctrie_remove_lookup(ptree, key, &freenode); \ name##_PCTRIE_REMOVE_BASE(ptree, freenode); \ return name##_PCTRIE_VAL2PTR(val); \ } struct pctrie_iter; void *pctrie_insert_lookup(struct pctrie *ptree, uint64_t *val, - uint64_t **found_out); -void *pctrie_insert_lookup_gt(struct pctrie *ptree, uint64_t *val, - uint64_t **found_out, struct pctrie_node **neighbor_out); -void *pctrie_insert_lookup_lt(struct pctrie *ptree, uint64_t *val, - uint64_t **found_out, struct pctrie_node **neighbor_out); -void *pctrie_insert_lookup_strict(struct pctrie *ptree, - uint64_t *val); -void pctrie_insert_node(void *parentp, - struct pctrie_node *parent, uint64_t *val); + struct pctrie_node **parent_out, uint64_t **found_out); +void *pctrie_insert_lookup_strict(struct pctrie *ptree, uint64_t *val, + struct pctrie_node **parent_out); +void pctrie_insert_node(uint64_t *val, struct pctrie_node *parent, + void *parentp, struct pctrie_node *child); uint64_t *pctrie_lookup(struct pctrie *ptree, uint64_t key); uint64_t *pctrie_lookup_unlocked(struct pctrie *ptree, uint64_t key, smr_t smr); uint64_t *pctrie_iter_lookup(struct pctrie_iter *it, uint64_t index); uint64_t *pctrie_iter_stride(struct pctrie_iter *it, int stride); uint64_t *pctrie_iter_next(struct pctrie_iter *it); uint64_t *pctrie_iter_prev(struct pctrie_iter *it); void *pctrie_iter_insert_lookup(struct pctrie_iter *it, uint64_t *val); uint64_t *pctrie_lookup_ge(struct pctrie *ptree, uint64_t key); -uint64_t *pctrie_subtree_lookup_gt(struct pctrie_node *node, - uint64_t key); uint64_t *pctrie_iter_lookup_ge(struct pctrie_iter *it, uint64_t index); uint64_t *pctrie_iter_jump_ge(struct pctrie_iter *it, int64_t jump); uint64_t *pctrie_lookup_le(struct pctrie *ptree, uint64_t key); -uint64_t *pctrie_subtree_lookup_lt(struct pctrie_node *node, - uint64_t key); +uint64_t *pctrie_subtree_lookup_lt(struct pctrie *ptree, + struct pctrie_node *node, uint64_t key); uint64_t *pctrie_iter_lookup_le(struct pctrie_iter *it, uint64_t index); uint64_t *pctrie_iter_jump_le(struct pctrie_iter *it, int64_t jump); struct pctrie_node *pctrie_reclaim_begin(struct pctrie_node **pnode, struct pctrie *ptree); struct pctrie_node *pctrie_reclaim_resume(struct pctrie_node **pnode); struct pctrie_node *pctrie_reclaim_begin_cb(struct pctrie_node **pnode, struct pctrie *ptree, pctrie_cb_t callback, int keyoff, void *arg); struct pctrie_node *pctrie_reclaim_resume_cb(struct pctrie_node **pnode, pctrie_cb_t callback, int keyoff, void *arg); uint64_t *pctrie_remove_lookup(struct pctrie *ptree, uint64_t index, struct pctrie_node **killnode); uint64_t *pctrie_iter_remove(struct pctrie_iter *it, struct pctrie_node **freenode); uint64_t *pctrie_iter_value(struct pctrie_iter *it); uint64_t *pctrie_replace(struct pctrie *ptree, uint64_t *newval); size_t pctrie_node_size(void); int pctrie_zone_init(void *mem, int size, int flags); /* * Each search path in the trie terminates at a leaf, which is a pointer to a * value marked with a set 1-bit. A leaf may be associated with a null pointer * to indicate no value there. */ #define PCTRIE_ISLEAF 0x1 #define PCTRIE_NULL (struct pctrie_node *)PCTRIE_ISLEAF static __inline void pctrie_init(struct pctrie *ptree) { ptree->pt_root = PCTRIE_NULL; } static __inline bool pctrie_is_empty(struct pctrie *ptree) { return (ptree->pt_root == PCTRIE_NULL); } /* Set of all flag bits stored in node pointers. */ #define PCTRIE_FLAGS (PCTRIE_ISLEAF) /* Minimum align parameter for uma_zcreate. */ #define PCTRIE_PAD PCTRIE_FLAGS /* * These widths should allow the pointers to a node's children to fit within * a single cache line. The extra levels from a narrow width should not be * a problem thanks to path compression. */ #ifdef __LP64__ #define PCTRIE_WIDTH 4 #else #define PCTRIE_WIDTH 3 #endif #define PCTRIE_COUNT (1 << PCTRIE_WIDTH) -#define PCTRIE_LIMIT howmany(sizeof(uint64_t) * NBBY, PCTRIE_WIDTH) - -struct pctrie_iter { - struct pctrie *ptree; - struct pctrie_node *path[PCTRIE_LIMIT]; - uint64_t index; - uint64_t limit; - int top; -}; - -static __inline void -pctrie_iter_reset(struct pctrie_iter *it) -{ - it->top = 0; -} - -static __inline void -pctrie_iter_init(struct pctrie_iter *it, struct pctrie *ptree) -{ - it->ptree = ptree; - it->top = 0; - it->limit = 0; -} - -static __inline void -pctrie_iter_limit_init(struct pctrie_iter *it, struct pctrie *ptree, - uint64_t limit) -{ - pctrie_iter_init(it, ptree); - it->limit = limit; -} #endif /* _KERNEL */ #endif /* !_SYS_PCTRIE_H_ */