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net: implement tcp coalescing in tcp_queue_rcv()

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Extend tcp coalescing implementing it from tcp_queue_rcv(), the main
receiver function when application is not blocked in recvmsg().

Function tcp_queue_rcv() is moved a bit to allow its call from
tcp_data_queue()

This gives good results especially if GRO could not kick, and if skb
head is a fragment.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Alexander Duyck <alexander.h.duyck@intel.com>
Cc: Neal Cardwell <ncardwell@google.com>
Cc: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Eric Dumazet 2012-05-02 09:58:29 +00:00 committed by David S. Miller
parent 923dd347b8
commit b081f85c29
3 changed files with 28 additions and 25 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

3
include/net/tcp.h
View File

@ -439,7 +439,8 @@ extern int tcp_disconnect(struct sock *sk, int flags);
void tcp_connect_init(struct sock *sk);
void tcp_finish_connect(struct sock *sk, struct sk_buff *skb);
void tcp_queue_rcv(struct sock *sk, struct sk_buff *skb, int hdrlen);
int __must_check tcp_queue_rcv(struct sock *sk, struct sk_buff *skb,
int hdrlen, bool *fragstolen);
/* From syncookies.c */
extern __u32 syncookie_secret[2][16-4+SHA_DIGEST_WORDS];

10
net/ipv4/tcp.c
View File

@ -981,8 +981,8 @@ static inline int select_size(const struct sock *sk, bool sg)
static int tcp_send_rcvq(struct sock *sk, struct msghdr *msg, size_t size)
{
struct sk_buff *skb;
struct tcp_skb_cb *cb;
struct tcphdr *th;
bool fragstolen;
skb = alloc_skb(size + sizeof(*th), sk->sk_allocation);
if (!skb)
@ -995,14 +995,14 @@ static int tcp_send_rcvq(struct sock *sk, struct msghdr *msg, size_t size)
if (memcpy_fromiovec(skb_put(skb, size), msg->msg_iov, size))
goto err_free;
cb = TCP_SKB_CB(skb);
TCP_SKB_CB(skb)->seq = tcp_sk(sk)->rcv_nxt;
TCP_SKB_CB(skb)->end_seq = TCP_SKB_CB(skb)->seq + size;
TCP_SKB_CB(skb)->ack_seq = tcp_sk(sk)->snd_una - 1;
tcp_queue_rcv(sk, skb, sizeof(*th));
if (tcp_queue_rcv(sk, skb, sizeof(*th), &fragstolen)) {
WARN_ON_ONCE(fragstolen); /* should not happen */
__kfree_skb(skb);
}
return size;
err_free:

40
net/ipv4/tcp_input.c
View File

@ -4739,6 +4739,22 @@ end:
skb_set_owner_r(skb, sk);
}
int tcp_queue_rcv(struct sock *sk, struct sk_buff *skb, int hdrlen,
bool *fragstolen)
{
int eaten;
struct sk_buff *tail = skb_peek_tail(&sk->sk_receive_queue);
__skb_pull(skb, hdrlen);
eaten = (tail &&
tcp_try_coalesce(sk, tail, skb, fragstolen)) ? 1 : 0;
tcp_sk(sk)->rcv_nxt = TCP_SKB_CB(skb)->end_seq;
if (!eaten) {
__skb_queue_tail(&sk->sk_receive_queue, skb);
skb_set_owner_r(skb, sk);
}
return eaten;
}
static void tcp_data_queue(struct sock *sk, struct sk_buff *skb)
{
@ -4785,20 +4801,12 @@ static void tcp_data_queue(struct sock *sk, struct sk_buff *skb)
}
if (eaten <= 0) {
struct sk_buff *tail;
queue_and_out:
if (eaten < 0 &&
tcp_try_rmem_schedule(sk, skb->truesize))
goto drop;
tail = skb_peek_tail(&sk->sk_receive_queue);
eaten = (tail &&
tcp_try_coalesce(sk, tail, skb,
&fragstolen)) ? 1 : 0;
if (eaten <= 0) {
skb_set_owner_r(skb, sk);
__skb_queue_tail(&sk->sk_receive_queue, skb);
}
eaten = tcp_queue_rcv(sk, skb, 0, &fragstolen);
}
tp->rcv_nxt = TCP_SKB_CB(skb)->end_seq;
if (skb->len)
@ -5493,14 +5501,6 @@ discard:
return 0;
}
void tcp_queue_rcv(struct sock *sk, struct sk_buff *skb, int hdrlen)
{
__skb_pull(skb, hdrlen);
__skb_queue_tail(&sk->sk_receive_queue, skb);
skb_set_owner_r(skb, sk);
tcp_sk(sk)->rcv_nxt = TCP_SKB_CB(skb)->end_seq;
}
/*
* TCP receive function for the ESTABLISHED state.
*
@ -5609,6 +5609,7 @@ int tcp_rcv_established(struct sock *sk, struct sk_buff *skb,
} else {
int eaten = 0;
int copied_early = 0;
bool fragstolen = false;
if (tp->copied_seq == tp->rcv_nxt &&
len - tcp_header_len <= tp->ucopy.len) {
@ -5666,7 +5667,8 @@ int tcp_rcv_established(struct sock *sk, struct sk_buff *skb,
NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPHPHITS);
/* Bulk data transfer: receiver */
tcp_queue_rcv(sk, skb, tcp_header_len);
eaten = tcp_queue_rcv(sk, skb, tcp_header_len,
&fragstolen);
}
tcp_event_data_recv(sk, skb);
@ -5688,7 +5690,7 @@ no_ack:
else
#endif
if (eaten)
__kfree_skb(skb);
kfree_skb_partial(skb, fragstolen);
else
sk->sk_data_ready(sk, 0);
return 0;