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From: Alexander Duyck <alexander.h.duyck@redhat.com>
Date: Wed, 31 Dec 2014 10:56:31 -0800
Subject: [PATCH] fib_trie: Move resize to after inflate/halve
This change consists of a cut/paste of resize to behind inflate and halve
so that I could remove the two function prototypes.
Signed-off-by: Alexander Duyck <alexander.h.duyck@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
--- 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
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 */
|
