Message ID | 1461899449-8096-3-git-send-email-edumazet@google.com |
---|---|
State | Changes Requested, archived |
Delegated to: | David Miller |
Headers | show |
On Thu, Apr 28, 2016 at 11:10 PM, Eric Dumazet <edumazet@google.com> wrote: > 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> Acked-by: Soheil Hassas Yeganeh <soheil@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 > Very nice!
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)
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(-)