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-rw-r--r--net/ipv4/fib_trie.c101
1 files changed, 41 insertions, 60 deletions
diff --git a/net/ipv4/fib_trie.c b/net/ipv4/fib_trie.c
index 63c2fa7b68c4..291bdf50a21f 100644
--- a/net/ipv4/fib_trie.c
+++ b/net/ipv4/fib_trie.c
@@ -48,7 +48,7 @@
* Patrick McHardy <kaber@trash.net>
*/
-#define VERSION "0.408"
+#define VERSION "0.409"
#include <asm/uaccess.h>
#include <asm/system.h>
@@ -164,6 +164,14 @@ 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 tnode *tnode_free_head;
+static size_t tnode_free_size;
+
+/*
+ * synchronize_rcu after call_rcu for that many pages; it should be especially
+ * useful before resizing the root node with PREEMPT_NONE configs; the value was
+ * obtained experimentally, aiming to avoid visible slowdown.
+ */
+static const int sync_pages = 128;
static struct kmem_cache *fn_alias_kmem __read_mostly;
static struct kmem_cache *trie_leaf_kmem __read_mostly;
@@ -317,8 +325,7 @@ static inline void check_tnode(const struct tnode *tn)
static const int halve_threshold = 25;
static const int inflate_threshold = 50;
static const int halve_threshold_root = 15;
-static const int inflate_threshold_root = 25;
-
+static const int inflate_threshold_root = 30;
static void __alias_free_mem(struct rcu_head *head)
{
@@ -393,6 +400,8 @@ static void tnode_free_safe(struct tnode *tn)
BUG_ON(IS_LEAF(tn));
tn->tnode_free = tnode_free_head;
tnode_free_head = tn;
+ tnode_free_size += sizeof(struct tnode) +
+ (sizeof(struct node *) << tn->bits);
}
static void tnode_free_flush(void)
@@ -404,6 +413,11 @@ static void tnode_free_flush(void)
tn->tnode_free = NULL;
tnode_free(tn);
}
+
+ if (tnode_free_size >= PAGE_SIZE * sync_pages) {
+ tnode_free_size = 0;
+ synchronize_rcu();
+ }
}
static struct leaf *leaf_new(void)
@@ -499,14 +513,14 @@ static void tnode_put_child_reorg(struct tnode *tn, int i, struct node *n,
rcu_assign_pointer(tn->child[i], n);
}
+#define MAX_WORK 10
static struct node *resize(struct trie *t, struct tnode *tn)
{
int i;
- int err = 0;
struct tnode *old_tn;
int inflate_threshold_use;
int halve_threshold_use;
- int max_resize;
+ int max_work;
if (!tn)
return NULL;
@@ -521,18 +535,7 @@ static struct node *resize(struct trie *t, struct tnode *tn)
}
/* One child */
if (tn->empty_children == tnode_child_length(tn) - 1)
- for (i = 0; i < tnode_child_length(tn); i++) {
- struct node *n;
-
- n = tn->child[i];
- if (!n)
- continue;
-
- /* compress one level */
- node_set_parent(n, NULL);
- tnode_free_safe(tn);
- return n;
- }
+ goto one_child;
/*
* Double as long as the resulting node has a number of
* nonempty nodes that are above the threshold.
@@ -601,14 +604,17 @@ static struct node *resize(struct trie *t, struct tnode *tn)
/* Keep root node larger */
- if (!tn->parent)
+ if (!node_parent((struct node*) tn)) {
inflate_threshold_use = inflate_threshold_root;
- else
+ halve_threshold_use = halve_threshold_root;
+ }
+ else {
inflate_threshold_use = inflate_threshold;
+ halve_threshold_use = halve_threshold;
+ }
- err = 0;
- max_resize = 10;
- while ((tn->full_children > 0 && max_resize-- &&
+ 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))) {
@@ -625,35 +631,19 @@ static struct node *resize(struct trie *t, struct tnode *tn)
}
}
- if (max_resize < 0) {
- if (!tn->parent)
- pr_warning("Fix inflate_threshold_root."
- " Now=%d size=%d bits\n",
- inflate_threshold_root, tn->bits);
- else
- pr_warning("Fix inflate_threshold."
- " Now=%d size=%d bits\n",
- inflate_threshold, tn->bits);
- }
-
check_tnode(tn);
+ /* Return if at least one inflate is run */
+ if( max_work != MAX_WORK)
+ return (struct node *) tn;
+
/*
* Halve as long as the number of empty children in this
* node is above threshold.
*/
-
- /* Keep root node larger */
-
- if (!tn->parent)
- halve_threshold_use = halve_threshold_root;
- else
- halve_threshold_use = halve_threshold;
-
- err = 0;
- max_resize = 10;
- while (tn->bits > 1 && max_resize-- &&
+ 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)) {
@@ -668,19 +658,10 @@ static struct node *resize(struct trie *t, struct tnode *tn)
}
}
- if (max_resize < 0) {
- if (!tn->parent)
- pr_warning("Fix halve_threshold_root."
- " Now=%d size=%d bits\n",
- halve_threshold_root, tn->bits);
- else
- pr_warning("Fix halve_threshold."
- " Now=%d size=%d bits\n",
- halve_threshold, tn->bits);
- }
/* Only one child remains */
- if (tn->empty_children == tnode_child_length(tn) - 1)
+ if (tn->empty_children == tnode_child_length(tn) - 1) {
+one_child:
for (i = 0; i < tnode_child_length(tn); i++) {
struct node *n;
@@ -694,7 +675,7 @@ static struct node *resize(struct trie *t, struct tnode *tn)
tnode_free_safe(tn);
return n;
}
-
+ }
return (struct node *) tn;
}
@@ -1435,7 +1416,7 @@ static int fn_trie_lookup(struct fib_table *tb, const struct flowi *flp,
cindex = tkey_extract_bits(mask_pfx(key, current_prefix_length),
pos, bits);
- n = tnode_get_child(pn, cindex);
+ n = tnode_get_child_rcu(pn, cindex);
if (n == NULL) {
#ifdef CONFIG_IP_FIB_TRIE_STATS
@@ -1570,7 +1551,7 @@ backtrace:
if (chopped_off <= pn->bits) {
cindex &= ~(1 << (chopped_off-1));
} else {
- struct tnode *parent = node_parent((struct node *) pn);
+ struct tnode *parent = node_parent_rcu((struct node *) pn);
if (!parent)
goto failed;
@@ -1783,7 +1764,7 @@ static struct leaf *trie_firstleaf(struct trie *t)
static struct leaf *trie_nextleaf(struct leaf *l)
{
struct node *c = (struct node *) l;
- struct tnode *p = node_parent(c);
+ struct tnode *p = node_parent_rcu(c);
if (!p)
return NULL; /* trie with just one leaf */
@@ -2391,7 +2372,7 @@ static inline const char *rtn_scope(char *buf, size_t len, enum rt_scope_t s)
}
}
-static const char *rtn_type_names[__RTN_MAX] = {
+static const char *const rtn_type_names[__RTN_MAX] = {
[RTN_UNSPEC] = "UNSPEC",
[RTN_UNICAST] = "UNICAST",
[RTN_LOCAL] = "LOCAL",
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.