litmus-rt.git - The LITMUS^RT kernel.

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author	Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>	2013-09-30 01:49:47 -0400
committer	Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>	2013-09-30 15:33:26 -0400
commit	bd3129fc5e8868df74ffa803c7fec527976bbf1c (patch)
tree	f437934fa8074b889f4cdfd0f3ac3e1a4ebc3a16 /include/uapi/linux/errqueue.h
parent	60b0fe372499f66e0c965dc0594320438a3b711c (diff)

netfilter: ipset: order matches and targets separatedly in xt_set.c

Signed-off-by: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>

Diffstat (limited to 'include/uapi/linux/errqueue.h')

0 files changed, 0 insertions, 0 deletions

/* * 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> /* * 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 */ #define RADIX_INDEX(vma) ((vma)->vm_pgoff) #define VMA_SIZE(vma) (((vma)->vm_end - (vma)->vm_start) >> PAGE_SHIFT) /* avoid overflow */ #define HEAP_INDEX(vma) ((vma)->vm_pgoff + (VMA_SIZE(vma) - 1)) static void get_index(const struct prio_tree_root *root, const struct prio_tree_node *node, unsigned long *radix, unsigned long *heap) { if (root->raw) { struct vm_area_struct *vma = prio_tree_entry( node, struct vm_area_struct, shared.prio_tree_node); *radix = RADIX_INDEX(vma); *heap = HEAP_INDEX(vma); } else { *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]; } /* * 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 *first = NULL, *prev, *last = NULL; if (max_heap_index > prio_tree_maxindex(root->index_bits)) root->index_bits++; while (max_heap_index > prio_tree_maxindex(root->index_bits)) { root->index_bits++; if (prio_tree_empty(root)) continue; if (first == NULL) { first = root->prio_tree_node; prio_tree_remove(root, root->prio_tree_node); INIT_PRIO_TREE_NODE(first); last = first; } else { prev = last; last = root->prio_tree_node; prio_tree_remove(root, root->prio_tree_node); INIT_PRIO_TREE_NODE(last); prev->left = last; last->parent = prev; } } INIT_PRIO_TREE_NODE(node); if (first) { node->left = first; first->parent = node; } else last = node; if (!prio_tree_empty(root)) { last->left = root->prio_tree_node; last->left->parent = last; } 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). */ node->parent = node; root->prio_tree_node = node; } else { node->parent = old->parent; if (old->parent->left == old) old->parent->left = node; else old->parent->right = node; } if (!prio_tree_left_empty(old)) { node->left = old->left; old->left->parent = node; } if (!prio_tree_right_empty(old)) { node->right = old->right; old->right->parent = node; } 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); cur->right = node; node->parent = cur; return res; } else cur = cur->right; } else { if (prio_tree_left_empty(cur)) { INIT_PRIO_TREE_NODE(node); cur->left = node; node->parent = cur; 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; } /* * Remove a prio_tree_node @node from a radix priority search tree @root. The


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