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| author | Eric Dumazet <dada1@cosmosbay.com> | 2007-02-09 15:44:52 -0800 |
|---|---|---|
| committer | David S. Miller <davem@sunset.davemloft.net> | 2007-02-10 23:20:29 -0800 |
| commit | 95f30b336b944e3e418f825044b4793d9e9aac09 (patch) | |
| tree | 4faf8cc7a061fdf7d85f94768ca1150f8580e700 /net/ipv4/udp.c | |
| parent | 4768fbcbcfbbcacb785ae08eef33767a0b4fdcdd (diff) | |
| download | lwn-95f30b336b944e3e418f825044b4793d9e9aac09.tar.gz lwn-95f30b336b944e3e418f825044b4793d9e9aac09.zip | |
[UDP]: UDP can use sk_hash to speedup lookups
In a prior patch, I introduced a sk_hash field (__sk_common.skc_hash) to let
tcp lookups use one cache line per unmatched entry instead of two.
We can also use sk_hash to speedup UDP part as well. We store in sk_hash the
hnum value, and use sk->sk_hash (same cache line than 'next' pointer),
instead of inet->num (different cache line)
Note : We still have a false sharing problem for SMP machines, because
sock_hold(sock) dirties the cache line containing the 'next' pointer. Not
counting the udp_hash_lock rwlock. (did someone mentioned RCU ? :) )
Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4/udp.c')
| -rw-r--r-- | net/ipv4/udp.c | 9 |
1 files changed, 5 insertions, 4 deletions
diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c index 2a246de6a671..ce6c46034314 100644 --- a/net/ipv4/udp.c +++ b/net/ipv4/udp.c @@ -120,7 +120,7 @@ static inline int __udp_lib_lport_inuse(__u16 num, struct hlist_head udptable[]) struct hlist_node *node; sk_for_each(sk, node, &udptable[num & (UDP_HTABLE_SIZE - 1)]) - if (inet_sk(sk)->num == num) + if (sk->sk_hash == num) return 1; return 0; } @@ -191,7 +191,7 @@ gotit: head = &udptable[snum & (UDP_HTABLE_SIZE - 1)]; sk_for_each(sk2, node, head) - if (inet_sk(sk2)->num == snum && + if (sk2->sk_hash == snum && sk2 != sk && (!sk2->sk_reuse || !sk->sk_reuse) && (!sk2->sk_bound_dev_if || !sk->sk_bound_dev_if @@ -200,6 +200,7 @@ gotit: goto fail; } inet_sk(sk)->num = snum; + sk->sk_hash = snum; if (sk_unhashed(sk)) { head = &udptable[snum & (UDP_HTABLE_SIZE - 1)]; sk_add_node(sk, head); @@ -247,7 +248,7 @@ static struct sock *__udp4_lib_lookup(__be32 saddr, __be16 sport, sk_for_each(sk, node, &udptable[hnum & (UDP_HTABLE_SIZE - 1)]) { struct inet_sock *inet = inet_sk(sk); - if (inet->num == hnum && !ipv6_only_sock(sk)) { + if (sk->sk_hash == hnum && !ipv6_only_sock(sk)) { int score = (sk->sk_family == PF_INET ? 1 : 0); if (inet->rcv_saddr) { if (inet->rcv_saddr != daddr) @@ -296,7 +297,7 @@ static inline struct sock *udp_v4_mcast_next(struct sock *sk, sk_for_each_from(s, node) { struct inet_sock *inet = inet_sk(s); - if (inet->num != hnum || + if (s->sk_hash != hnum || (inet->daddr && inet->daddr != rmt_addr) || (inet->dport != rmt_port && inet->dport) || (inet->rcv_saddr && inet->rcv_saddr != loc_addr) || |