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| author | Eric Dumazet <edumazet@google.com> | 2016-04-01 17:52:17 +0200 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2016-04-05 04:11:20 +0200 |
| commit | 3b24d854cb35383c30642116e5992fd619bdc9bc (patch) | |
| tree | a2a0c8c8ad3f7f974d6a9b11b17865edfb62d6d1 /include/net/inet6_hashtables.h | |
| parent | inet: reqsk_alloc() needs to take care of dead listeners (diff) | |
| download | linux-3b24d854cb35383c30642116e5992fd619bdc9bc.tar.xz linux-3b24d854cb35383c30642116e5992fd619bdc9bc.zip | |
tcp/dccp: do not touch listener sk_refcnt under synflood
When a SYNFLOOD targets a non SO_REUSEPORT listener, multiple
cpus contend on sk->sk_refcnt and sk->sk_wmem_alloc changes.
By letting listeners use SOCK_RCU_FREE infrastructure,
we can relax TCP_LISTEN lookup rules and avoid touching sk_refcnt
Note that we still use SLAB_DESTROY_BY_RCU rules for other sockets,
only listeners are impacted by this change.
Peak performance under SYNFLOOD is increased by ~33% :
On my test machine, I could process 3.2 Mpps instead of 2.4 Mpps
Most consuming functions are now skb_set_owner_w() and sock_wfree()
contending on sk->sk_wmem_alloc when cooking SYNACK and freeing them.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'include/net/inet6_hashtables.h')
| -rw-r--r-- | include/net/inet6_hashtables.h | 12 |
1 files changed, 8 insertions, 4 deletions
diff --git a/include/net/inet6_hashtables.h b/include/net/inet6_hashtables.h index 28332bdac333..b87becacd9d3 100644 --- a/include/net/inet6_hashtables.h +++ b/include/net/inet6_hashtables.h @@ -66,13 +66,15 @@ static inline struct sock *__inet6_lookup(struct net *net, const __be16 sport, const struct in6_addr *daddr, const u16 hnum, - const int dif) + const int dif, + bool *refcounted) { struct sock *sk = __inet6_lookup_established(net, hashinfo, saddr, sport, daddr, hnum, dif); + *refcounted = true; if (sk) return sk; - + *refcounted = false; return inet6_lookup_listener(net, hashinfo, skb, doff, saddr, sport, daddr, hnum, dif); } @@ -81,17 +83,19 @@ static inline struct sock *__inet6_lookup_skb(struct inet_hashinfo *hashinfo, struct sk_buff *skb, int doff, const __be16 sport, const __be16 dport, - int iif) + int iif, + bool *refcounted) { struct sock *sk = skb_steal_sock(skb); + *refcounted = true; if (sk) return sk; return __inet6_lookup(dev_net(skb_dst(skb)->dev), hashinfo, skb, doff, &ipv6_hdr(skb)->saddr, sport, &ipv6_hdr(skb)->daddr, ntohs(dport), - iif); + iif, refcounted); } struct sock *inet6_lookup(struct net *net, struct inet_hashinfo *hashinfo, |