diff options
Diffstat (limited to 'net/ipv4/fib_trie.c')
| -rw-r--r-- | net/ipv4/fib_trie.c | 52 |
1 files changed, 41 insertions, 11 deletions
diff --git a/net/ipv4/fib_trie.c b/net/ipv4/fib_trie.c index 63c2fa7b68c..fe3c846b99a 100644 --- a/net/ipv4/fib_trie.c +++ b/net/ipv4/fib_trie.c @@ -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; @@ -319,6 +327,8 @@ static const int inflate_threshold = 50; static const int halve_threshold_root = 15; static const int inflate_threshold_root = 25; +static int inflate_threshold_root_fix; +#define INFLATE_FIX_MAX 10 /* a comment in resize() */ static void __alias_free_mem(struct rcu_head *head) { @@ -393,6 +403,8 @@ 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 +416,11 @@ 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) @@ -602,7 +619,8 @@ static struct node *resize(struct trie *t, struct tnode *tn) /* Keep root node larger */ if (!tn->parent) - inflate_threshold_use = inflate_threshold_root; + inflate_threshold_use = inflate_threshold_root + + inflate_threshold_root_fix; else inflate_threshold_use = inflate_threshold; @@ -626,15 +644,27 @@ 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 + if (!tn->parent) { + /* + * It was observed that during large updates even + * inflate_threshold_root = 35 might be needed to avoid + * this warning; but it should be temporary, so let's + * try to handle this automatically. + */ + if (inflate_threshold_root_fix < INFLATE_FIX_MAX) + inflate_threshold_root_fix++; + else + pr_warning("Fix inflate_threshold_root." + " Now=%d size=%d bits fix=%d\n", + inflate_threshold_root, tn->bits, + inflate_threshold_root_fix); + } else { pr_warning("Fix inflate_threshold." " Now=%d size=%d bits\n", inflate_threshold, tn->bits); - } + } + } else if (max_resize > 3 && !tn->parent && inflate_threshold_root_fix) + inflate_threshold_root_fix--; check_tnode(tn); @@ -1435,7 +1465,7 @@ 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 +1600,7 @@ 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 +1813,7 @@ 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 +2421,7 @@ 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", |