diff options
Diffstat (limited to 'net')
| -rw-r--r-- | net/ipv4/fib_trie.c | 311 |
1 files changed, 154 insertions, 157 deletions
diff --git a/net/ipv4/fib_trie.c b/net/ipv4/fib_trie.c index 987b06d1effe..d044fa355f69 100644 --- a/net/ipv4/fib_trie.c +++ b/net/ipv4/fib_trie.c @@ -149,8 +149,6 @@ struct trie { static void tnode_put_child_reorg(struct tnode *tn, unsigned long i, struct tnode *n, int wasfull); static struct tnode *resize(struct trie *t, struct tnode *tn); -static struct tnode *inflate(struct trie *t, struct tnode *tn); -static struct tnode *halve(struct trie *t, struct tnode *tn); /* tnodes to free after resize(); protected by RTNL */ static struct callback_head *tnode_free_head; static size_t tnode_free_size; @@ -447,161 +445,6 @@ static void put_child_root(struct tnode *tp, struct trie *t, rcu_assign_pointer(t->trie, n); } -#define MAX_WORK 10 -static struct tnode *resize(struct trie *t, struct tnode *tn) -{ - struct tnode *old_tn, *n = NULL; - int inflate_threshold_use; - int halve_threshold_use; - int max_work; - - if (!tn) - return NULL; - - pr_debug("In tnode_resize %p inflate_threshold=%d threshold=%d\n", - tn, inflate_threshold, halve_threshold); - - /* No children */ - if (tn->empty_children > (tnode_child_length(tn) - 1)) - goto no_children; - - /* One child */ - if (tn->empty_children == (tnode_child_length(tn) - 1)) - goto one_child; - /* - * Double as long as the resulting node has a number of - * nonempty nodes that are above the threshold. - */ - - /* - * From "Implementing a dynamic compressed trie" by Stefan Nilsson of - * the Helsinki University of Technology and Matti Tikkanen of Nokia - * Telecommunications, page 6: - * "A node is doubled if the ratio of non-empty children to all - * children in the *doubled* node is at least 'high'." - * - * 'high' in this instance is the variable 'inflate_threshold'. It - * is expressed as a percentage, so we multiply it with - * tnode_child_length() and instead of multiplying by 2 (since the - * child array will be doubled by inflate()) and multiplying - * the left-hand side by 100 (to handle the percentage thing) we - * multiply the left-hand side by 50. - * - * The left-hand side may look a bit weird: tnode_child_length(tn) - * - tn->empty_children is of course the number of non-null children - * in the current node. tn->full_children is the number of "full" - * children, that is non-null tnodes with a skip value of 0. - * All of those will be doubled in the resulting inflated tnode, so - * we just count them one extra time here. - * - * A clearer way to write this would be: - * - * to_be_doubled = tn->full_children; - * not_to_be_doubled = tnode_child_length(tn) - tn->empty_children - - * tn->full_children; - * - * new_child_length = tnode_child_length(tn) * 2; - * - * new_fill_factor = 100 * (not_to_be_doubled + 2*to_be_doubled) / - * new_child_length; - * if (new_fill_factor >= inflate_threshold) - * - * ...and so on, tho it would mess up the while () loop. - * - * anyway, - * 100 * (not_to_be_doubled + 2*to_be_doubled) / new_child_length >= - * inflate_threshold - * - * avoid a division: - * 100 * (not_to_be_doubled + 2*to_be_doubled) >= - * inflate_threshold * new_child_length - * - * expand not_to_be_doubled and to_be_doubled, and shorten: - * 100 * (tnode_child_length(tn) - tn->empty_children + - * tn->full_children) >= inflate_threshold * new_child_length - * - * expand new_child_length: - * 100 * (tnode_child_length(tn) - tn->empty_children + - * tn->full_children) >= - * inflate_threshold * tnode_child_length(tn) * 2 - * - * shorten again: - * 50 * (tn->full_children + tnode_child_length(tn) - - * tn->empty_children) >= inflate_threshold * - * tnode_child_length(tn) - * - */ - - /* Keep root node larger */ - - if (!node_parent(tn)) { - inflate_threshold_use = inflate_threshold_root; - halve_threshold_use = halve_threshold_root; - } else { - inflate_threshold_use = inflate_threshold; - halve_threshold_use = halve_threshold; - } - - max_work = MAX_WORK; - while ((tn->full_children > 0 && max_work-- && - 50 * (tn->full_children + tnode_child_length(tn) - - tn->empty_children) - >= inflate_threshold_use * tnode_child_length(tn))) { - - old_tn = tn; - tn = inflate(t, tn); - - if (IS_ERR(tn)) { - tn = old_tn; -#ifdef CONFIG_IP_FIB_TRIE_STATS - this_cpu_inc(t->stats->resize_node_skipped); -#endif - break; - } - } - - /* Return if at least one inflate is run */ - if (max_work != MAX_WORK) - return tn; - - /* - * Halve as long as the number of empty children in this - * node is above threshold. - */ - - max_work = MAX_WORK; - while (tn->bits > 1 && max_work-- && - 100 * (tnode_child_length(tn) - tn->empty_children) < - halve_threshold_use * tnode_child_length(tn)) { - - old_tn = tn; - tn = halve(t, tn); - if (IS_ERR(tn)) { - tn = old_tn; -#ifdef CONFIG_IP_FIB_TRIE_STATS - this_cpu_inc(t->stats->resize_node_skipped); -#endif - break; - } - } - - - /* Only one child remains */ - if (tn->empty_children == (tnode_child_length(tn) - 1)) { - unsigned long i; -one_child: - for (i = tnode_child_length(tn); !n && i;) - n = tnode_get_child(tn, --i); -no_children: - /* compress one level */ - node_set_parent(n, NULL); - tnode_free_safe(tn); - return n; - } - return tn; -} - - static void tnode_clean_free(struct tnode *tn) { struct tnode *tofree; @@ -804,6 +647,160 @@ nomem: return ERR_PTR(-ENOMEM); } +#define MAX_WORK 10 +static struct tnode *resize(struct trie *t, struct tnode *tn) +{ + struct tnode *old_tn, *n = NULL; + int inflate_threshold_use; + int halve_threshold_use; + int max_work; + + if (!tn) + return NULL; + + pr_debug("In tnode_resize %p inflate_threshold=%d threshold=%d\n", + tn, inflate_threshold, halve_threshold); + + /* No children */ + if (tn->empty_children > (tnode_child_length(tn) - 1)) + goto no_children; + + /* One child */ + if (tn->empty_children == (tnode_child_length(tn) - 1)) + goto one_child; + /* + * Double as long as the resulting node has a number of + * nonempty nodes that are above the threshold. + */ + + /* + * From "Implementing a dynamic compressed trie" by Stefan Nilsson of + * the Helsinki University of Technology and Matti Tikkanen of Nokia + * Telecommunications, page 6: + * "A node is doubled if the ratio of non-empty children to all + * children in the *doubled* node is at least 'high'." + * + * 'high' in this instance is the variable 'inflate_threshold'. It + * is expressed as a percentage, so we multiply it with + * tnode_child_length() and instead of multiplying by 2 (since the + * child array will be doubled by inflate()) and multiplying + * the left-hand side by 100 (to handle the percentage thing) we + * multiply the left-hand side by 50. + * + * The left-hand side may look a bit weird: tnode_child_length(tn) + * - tn->empty_children is of course the number of non-null children + * in the current node. tn->full_children is the number of "full" + * children, that is non-null tnodes with a skip value of 0. + * All of those will be doubled in the resulting inflated tnode, so + * we just count them one extra time here. + * + * A clearer way to write this would be: + * + * to_be_doubled = tn->full_children; + * not_to_be_doubled = tnode_child_length(tn) - tn->empty_children - + * tn->full_children; + * + * new_child_length = tnode_child_length(tn) * 2; + * + * new_fill_factor = 100 * (not_to_be_doubled + 2*to_be_doubled) / + * new_child_length; + * if (new_fill_factor >= inflate_threshold) + * + * ...and so on, tho it would mess up the while () loop. + * + * anyway, + * 100 * (not_to_be_doubled + 2*to_be_doubled) / new_child_length >= + * inflate_threshold + * + * avoid a division: + * 100 * (not_to_be_doubled + 2*to_be_doubled) >= + * inflate_threshold * new_child_length + * + * expand not_to_be_doubled and to_be_doubled, and shorten: + * 100 * (tnode_child_length(tn) - tn->empty_children + + * tn->full_children) >= inflate_threshold * new_child_length + * + * expand new_child_length: + * 100 * (tnode_child_length(tn) - tn->empty_children + + * tn->full_children) >= + * inflate_threshold * tnode_child_length(tn) * 2 + * + * shorten again: + * 50 * (tn->full_children + tnode_child_length(tn) - + * tn->empty_children) >= inflate_threshold * + * tnode_child_length(tn) + * + */ + + /* Keep root node larger */ + + if (!node_parent(tn)) { + inflate_threshold_use = inflate_threshold_root; + halve_threshold_use = halve_threshold_root; + } else { + inflate_threshold_use = inflate_threshold; + halve_threshold_use = halve_threshold; + } + + max_work = MAX_WORK; + while ((tn->full_children > 0 && max_work-- && + 50 * (tn->full_children + tnode_child_length(tn) + - tn->empty_children) + >= inflate_threshold_use * tnode_child_length(tn))) { + + old_tn = tn; + tn = inflate(t, tn); + + if (IS_ERR(tn)) { + tn = old_tn; +#ifdef CONFIG_IP_FIB_TRIE_STATS + this_cpu_inc(t->stats->resize_node_skipped); +#endif + break; + } + } + + /* Return if at least one inflate is run */ + if (max_work != MAX_WORK) + return tn; + + /* + * Halve as long as the number of empty children in this + * node is above threshold. + */ + + max_work = MAX_WORK; + while (tn->bits > 1 && max_work-- && + 100 * (tnode_child_length(tn) - tn->empty_children) < + halve_threshold_use * tnode_child_length(tn)) { + + old_tn = tn; + tn = halve(t, tn); + if (IS_ERR(tn)) { + tn = old_tn; +#ifdef CONFIG_IP_FIB_TRIE_STATS + this_cpu_inc(t->stats->resize_node_skipped); +#endif + break; + } + } + + + /* Only one child remains */ + if (tn->empty_children == (tnode_child_length(tn) - 1)) { + unsigned long i; +one_child: + for (i = tnode_child_length(tn); !n && i;) + n = tnode_get_child(tn, --i); +no_children: + /* compress one level */ + node_set_parent(n, NULL); + tnode_free_safe(tn); + return n; + } + return tn; +} + /* readside must use rcu_read_lock currently dump routines via get_fa_head and dump */ |