[PATCH v2 net-next 2/7] tcp: do not block bh during prequeue processing
From: Eric Dumazet <edumazet@google.com>
Date: 2016-04-29 03:10:59
Subsystem:
networking [general], networking [tcp], the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Neal Cardwell, Linus Torvalds
AFAIK, nothing in current TCP stack absolutely wants BH
being disabled once socket is owned by a thread running in
process context.
As mentioned in my prior patch ("tcp: give prequeue mode some care"),
processing a batch of packets might take time, better not block BH
at all.
Signed-off-by: Eric Dumazet <edumazet@google.com>
---
net/ipv4/tcp.c | 4 ----
net/ipv4/tcp_input.c | 30 ++----------------------------
2 files changed, 2 insertions(+), 32 deletions(-)
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index b24c6ed4a04f..4787f86ae64c 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c@@ -1449,12 +1449,8 @@ static void tcp_prequeue_process(struct sock *sk) NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPPREQUEUED); - /* RX process wants to run with disabled BHs, though it is not - * necessary */ - local_bh_disable(); while ((skb = __skb_dequeue(&tp->ucopy.prequeue)) != NULL) sk_backlog_rcv(sk, skb); - local_bh_enable(); /* Clear memory counter. */ tp->ucopy.memory = 0;
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index ac85fb42a5a2..6171f92be090 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c@@ -4611,14 +4611,12 @@ static void tcp_data_queue(struct sock *sk, struct sk_buff *skb) __set_current_state(TASK_RUNNING); - local_bh_enable(); if (!skb_copy_datagram_msg(skb, 0, tp->ucopy.msg, chunk)) { tp->ucopy.len -= chunk; tp->copied_seq += chunk; eaten = (chunk == skb->len); tcp_rcv_space_adjust(sk); } - local_bh_disable(); } if (eaten <= 0) {
@@ -5134,7 +5132,6 @@ static int tcp_copy_to_iovec(struct sock *sk, struct sk_buff *skb, int hlen) int chunk = skb->len - hlen; int err; - local_bh_enable(); if (skb_csum_unnecessary(skb)) err = skb_copy_datagram_msg(skb, hlen, tp->ucopy.msg, chunk); else
@@ -5146,32 +5143,9 @@ static int tcp_copy_to_iovec(struct sock *sk, struct sk_buff *skb, int hlen) tcp_rcv_space_adjust(sk); } - local_bh_disable(); return err; } -static __sum16 __tcp_checksum_complete_user(struct sock *sk, - struct sk_buff *skb) -{ - __sum16 result; - - if (sock_owned_by_user(sk)) { - local_bh_enable(); - result = __tcp_checksum_complete(skb); - local_bh_disable(); - } else { - result = __tcp_checksum_complete(skb); - } - return result; -} - -static inline bool tcp_checksum_complete_user(struct sock *sk, - struct sk_buff *skb) -{ - return !skb_csum_unnecessary(skb) && - __tcp_checksum_complete_user(sk, skb); -} - /* Does PAWS and seqno based validation of an incoming segment, flags will * play significant role here. */
@@ -5386,7 +5360,7 @@ void tcp_rcv_established(struct sock *sk, struct sk_buff *skb, } } if (!eaten) { - if (tcp_checksum_complete_user(sk, skb)) + if (tcp_checksum_complete(skb)) goto csum_error; if ((int)skb->truesize > sk->sk_forward_alloc)
@@ -5430,7 +5404,7 @@ no_ack: } slow_path: - if (len < (th->doff << 2) || tcp_checksum_complete_user(sk, skb)) + if (len < (th->doff << 2) || tcp_checksum_complete(skb)) goto csum_error; if (!th->ack && !th->rst && !th->syn)
--
2.8.0.rc3.226.g39d4020