diff options
| author | Paolo Abeni <pabeni@redhat.com> | 2017-03-30 15:03:06 +0300 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2017-03-31 06:05:24 +0300 |
| commit | 6c7c98bad4883a4a8710c96b2b44de482865eb6e (patch) | |
| tree | 0995daa9a97afde4b675dea6054701d04404a3ac /include/net/sock.h | |
| parent | 7801a3225e7fe05f7601ab42a5669ba633c4df54 (diff) | |
| download | linux-6c7c98bad4883a4a8710c96b2b44de482865eb6e.tar.xz | |
sock: avoid dirtying sk_stamp, if possible
sock_recv_ts_and_drops() unconditionally set sk->sk_stamp for
every packet, even if the SOCK_TIMESTAMP flag is not set in the
related socket.
If selinux is enabled, this cause a cache miss for every packet
since sk->sk_stamp and sk->sk_security share the same cacheline.
With this change sk_stamp is set only if the SOCK_TIMESTAMP
flag is set, and is cleared for the first packet, so that the user
perceived behavior is unchanged.
This gives up to 5% speed-up under udp-flood with small packets.
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'include/net/sock.h')
| -rw-r--r-- | include/net/sock.h | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/include/net/sock.h b/include/net/sock.h index cb241a0e8434..8e53158a7d95 100644 --- a/include/net/sock.h +++ b/include/net/sock.h @@ -2239,6 +2239,7 @@ sock_recv_timestamp(struct msghdr *msg, struct sock *sk, struct sk_buff *skb) void __sock_recv_ts_and_drops(struct msghdr *msg, struct sock *sk, struct sk_buff *skb); +#define SK_DEFAULT_STAMP (-1L * NSEC_PER_SEC) static inline void sock_recv_ts_and_drops(struct msghdr *msg, struct sock *sk, struct sk_buff *skb) { @@ -2249,8 +2250,10 @@ static inline void sock_recv_ts_and_drops(struct msghdr *msg, struct sock *sk, if (sk->sk_flags & FLAGS_TS_OR_DROPS || sk->sk_tsflags & TSFLAGS_ANY) __sock_recv_ts_and_drops(msg, sk, skb); - else + else if (unlikely(sk->sk_flags & SOCK_TIMESTAMP)) sk->sk_stamp = skb->tstamp; + else if (unlikely(sk->sk_stamp == SK_DEFAULT_STAMP)) + sk->sk_stamp = 0; } void __sock_tx_timestamp(__u16 tsflags, __u8 *tx_flags); |