| Message ID | 3fa2a7102e0ca7e89dac2e14e60469ac414bcef4.1621963632.git.pabeni@redhat.com (mailing list archive) |
|---|---|
| State | RFC, archived |
| Delegated to: | Mat Martineau |
| Headers | show |
| Series | mptcp: just another receive path refactor | expand |
On Tue, 25 May 2021, Paolo Abeni wrote: > After commit c2e6048fa1cf ("mptcp: fix race in release_cb") it's > pretty straight forward move the whole MPTCP rx path under the socket > lock leveraging the release_cb. > > We can drop a bunch of spin_lock pairs in the receive functions, use > a single receive queue and invoke __mptcp_move_skbs only when subflows > ask for it. > > This will allow more cleanup in the next patch > Like you said in the cover letter, the perf data will really help with understanding the performance tradeoff. I'm a little paranoid about the locking changes, since the mptcp_data_lock() is used to protect several things. What do you think about a debug patch (maybe temporarily in the export branch, but not upstreamed) that used spin_is_locked() or assert_spin_locked() to double check that there's still lock coverage where we expect it? Overall, I like this direction - hope the performance looks ok! -Mat > Signed-off-by: Paolo Abeni <pabeni@redhat.com> > --- > net/mptcp/protocol.c | 94 ++++++++++++++++++-------------------------- > net/mptcp/protocol.h | 2 +- > 2 files changed, 39 insertions(+), 57 deletions(-) > > diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c > index 6050431f4c86..57deea409d0c 100644 > --- a/net/mptcp/protocol.c > +++ b/net/mptcp/protocol.c > @@ -682,11 +682,6 @@ static bool move_skbs_to_msk(struct mptcp_sock *msk, struct sock *ssk) > struct sock *sk = (struct sock *)msk; > unsigned int moved = 0; > > - if (inet_sk_state_load(sk) == TCP_CLOSE) > - return; > - > - mptcp_data_lock(sk); > - > __mptcp_move_skbs_from_subflow(msk, ssk, &moved); > __mptcp_ofo_queue(msk); > > @@ -697,12 +692,11 @@ static bool move_skbs_to_msk(struct mptcp_sock *msk, struct sock *ssk) > */ > if (mptcp_pending_data_fin(sk, NULL)) > mptcp_schedule_work(sk); > - mptcp_data_unlock(sk); > > return moved > 0; > } > > -void mptcp_data_ready(struct sock *sk, struct sock *ssk) > +static void __mptcp_data_ready(struct sock *sk, struct sock *ssk) > { > struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk); > struct mptcp_sock *msk = mptcp_sk(sk); > @@ -731,6 +725,16 @@ void mptcp_data_ready(struct sock *sk, struct sock *ssk) > } > } > > +void mptcp_data_ready(struct sock *sk, struct sock *ssk) > +{ > + mptcp_data_lock(sk); > + if (!sock_owned_by_user(sk)) > + __mptcp_data_ready(sk, ssk); > + else > + set_bit(MPTCP_DEQUEUE, &mptcp_sk(sk)->flags); > + mptcp_data_unlock(sk); > +} > + > static bool mptcp_do_flush_join_list(struct mptcp_sock *msk) > { > struct mptcp_subflow_context *subflow; > @@ -967,7 +971,6 @@ static bool mptcp_wmem_alloc(struct sock *sk, int size) > if (msk->wmem_reserved >= size) > goto account; > > - mptcp_data_lock(sk); > if (!sk_wmem_schedule(sk, size)) { > mptcp_data_unlock(sk); > return false; > @@ -975,7 +978,6 @@ static bool mptcp_wmem_alloc(struct sock *sk, int size) > > sk->sk_forward_alloc -= size; > msk->wmem_reserved += size; > - mptcp_data_unlock(sk); > > account: > msk->wmem_reserved -= size; > @@ -1002,12 +1004,10 @@ static void mptcp_mem_reclaim_partial(struct sock *sk) > if (msk->wmem_reserved < 0) > return; > > - mptcp_data_lock(sk); > sk->sk_forward_alloc += msk->wmem_reserved; > sk_mem_reclaim_partial(sk); > msk->wmem_reserved = sk->sk_forward_alloc; > sk->sk_forward_alloc = 0; > - mptcp_data_unlock(sk); > } > > static void dfrag_uncharge(struct sock *sk, int len) > @@ -1092,9 +1092,7 @@ static void __mptcp_clean_una_wakeup(struct sock *sk) > > static void mptcp_clean_una_wakeup(struct sock *sk) > { > - mptcp_data_lock(sk); > __mptcp_clean_una_wakeup(sk); > - mptcp_data_unlock(sk); > } > > static void mptcp_enter_memory_pressure(struct sock *sk) > @@ -1713,16 +1711,22 @@ static void mptcp_wait_data(struct sock *sk, long *timeo) > remove_wait_queue(sk_sleep(sk), &wait); > } > > -static int __mptcp_recvmsg_mskq(struct mptcp_sock *msk, > +static bool __mptcp_move_skbs(struct sock *sk); > + > +static int __mptcp_recvmsg_mskq(struct sock *sk, > struct msghdr *msg, > size_t len, int flags, > struct scm_timestamping_internal *tss, > int *cmsg_flags) > { > + struct mptcp_sock *msk = mptcp_sk(sk); > struct sk_buff *skb, *tmp; > int copied = 0; > > - skb_queue_walk_safe(&msk->receive_queue, skb, tmp) { > + if (skb_queue_empty(&sk->sk_receive_queue) && !__mptcp_move_skbs(sk)) > + return 0; > + > + skb_queue_walk_safe(&sk->sk_receive_queue, skb, tmp) { > u32 offset = MPTCP_SKB_CB(skb)->offset; > u32 data_len = skb->len - offset; > u32 count = min_t(size_t, len - copied, data_len); > @@ -1754,7 +1758,7 @@ static int __mptcp_recvmsg_mskq(struct mptcp_sock *msk, > /* we will bulk release the skb memory later */ > skb->destructor = NULL; > msk->rmem_released += skb->truesize; > - __skb_unlink(skb, &msk->receive_queue); > + __skb_unlink(skb, &sk->sk_receive_queue); > __kfree_skb(skb); > } > > @@ -1875,16 +1879,9 @@ static void __mptcp_update_rmem(struct sock *sk) > msk->rmem_released = 0; > } > > -static void __mptcp_splice_receive_queue(struct sock *sk) > +static bool __mptcp_move_skbs(struct sock *sk) > { > struct mptcp_sock *msk = mptcp_sk(sk); > - > - skb_queue_splice_tail_init(&sk->sk_receive_queue, &msk->receive_queue); > -} > - > -static bool __mptcp_move_skbs(struct mptcp_sock *msk) > -{ > - struct sock *sk = (struct sock *)msk; > unsigned int moved = 0; > bool ret, done; > > @@ -1893,18 +1890,12 @@ static bool __mptcp_move_skbs(struct mptcp_sock *msk) > struct sock *ssk = mptcp_subflow_recv_lookup(msk); > bool slowpath; > > - /* we can have data pending in the subflows only if the msk > - * receive buffer was full at subflow_data_ready() time, > - * that is an unlikely slow path. > - */ > - if (likely(!ssk)) > + if (unlikely(!ssk)) > break; > > slowpath = lock_sock_fast(ssk); > - mptcp_data_lock(sk); > __mptcp_update_rmem(sk); > done = __mptcp_move_skbs_from_subflow(msk, ssk, &moved); > - mptcp_data_unlock(sk); > tcp_cleanup_rbuf(ssk, moved); > unlock_sock_fast(ssk, slowpath); > } while (!done); > @@ -1912,17 +1903,16 @@ static bool __mptcp_move_skbs(struct mptcp_sock *msk) > /* acquire the data lock only if some input data is pending */ > ret = moved > 0; > if (!RB_EMPTY_ROOT(&msk->out_of_order_queue) || > - !skb_queue_empty_lockless(&sk->sk_receive_queue)) { > - mptcp_data_lock(sk); > + !skb_queue_empty(&sk->sk_receive_queue)) { > __mptcp_update_rmem(sk); > ret |= __mptcp_ofo_queue(msk); > - __mptcp_splice_receive_queue(sk); > - mptcp_data_unlock(sk); > mptcp_cleanup_rbuf(msk); > } > - if (ret) > + if (ret) { > + set_bit(MPTCP_DATA_READY, &msk->flags); > mptcp_check_data_fin((struct sock *)msk); > - return !skb_queue_empty(&msk->receive_queue); > + } > + return ret; > } > > static int mptcp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, > @@ -1938,7 +1928,7 @@ static int mptcp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, > if (unlikely(flags & MSG_ERRQUEUE)) > return inet_recv_error(sk, msg, len, addr_len); > > - mptcp_lock_sock(sk, __mptcp_splice_receive_queue(sk)); > + lock_sock(sk); > if (unlikely(sk->sk_state == TCP_LISTEN)) { > copied = -ENOTCONN; > goto out_err; > @@ -1952,7 +1942,7 @@ static int mptcp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, > while (copied < len) { > int bytes_read; > > - bytes_read = __mptcp_recvmsg_mskq(msk, msg, len - copied, flags, &tss, &cmsg_flags); > + bytes_read = __mptcp_recvmsg_mskq(sk, msg, len - copied, flags, &tss, &cmsg_flags); > if (unlikely(bytes_read < 0)) { > if (!copied) > copied = bytes_read; > @@ -1964,9 +1954,6 @@ static int mptcp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, > /* be sure to advertise window change */ > mptcp_cleanup_rbuf(msk); > > - if (skb_queue_empty(&msk->receive_queue) && __mptcp_move_skbs(msk)) > - continue; > - > /* only the master socket status is relevant here. The exit > * conditions mirror closely tcp_recvmsg() > */ > @@ -1993,7 +1980,7 @@ static int mptcp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, > /* race breaker: the shutdown could be after the > * previous receive queue check > */ > - if (__mptcp_move_skbs(msk)) > + if (__mptcp_move_skbs(sk)) > continue; > break; > } > @@ -2018,16 +2005,11 @@ static int mptcp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, > mptcp_wait_data(sk, &timeo); > } > > - if (skb_queue_empty_lockless(&sk->sk_receive_queue) && > - skb_queue_empty(&msk->receive_queue)) { > - /* entire backlog drained, clear DATA_READY. */ > - clear_bit(MPTCP_DATA_READY, &msk->flags); > - > - /* .. race-breaker: ssk might have gotten new data > - * after last __mptcp_move_skbs() returned false. > + if (skb_queue_empty(&sk->sk_receive_queue)) { > + /* entire backlog drained, clear DATA_READY. > + * release_cb/__mptcp_move_skbs() will eventually set it again if needed > */ > - if (unlikely(__mptcp_move_skbs(msk))) > - set_bit(MPTCP_DATA_READY, &msk->flags); > + clear_bit(MPTCP_DATA_READY, &msk->flags); > } > > out_err: > @@ -2376,7 +2358,6 @@ static int __mptcp_init_sock(struct sock *sk) > INIT_LIST_HEAD(&msk->join_list); > INIT_LIST_HEAD(&msk->rtx_queue); > INIT_WORK(&msk->work, mptcp_worker); > - __skb_queue_head_init(&msk->receive_queue); > msk->out_of_order_queue = RB_ROOT; > msk->first_pending = NULL; > msk->wmem_reserved = 0; > @@ -2828,9 +2809,6 @@ void mptcp_destroy_common(struct mptcp_sock *msk) > > __mptcp_clear_xmit(sk); > > - /* move to sk_receive_queue, sk_stream_kill_queues will purge it */ > - skb_queue_splice_tail_init(&msk->receive_queue, &sk->sk_receive_queue); > - > skb_rbtree_purge(&msk->out_of_order_queue); > mptcp_token_destroy(msk); > mptcp_pm_free_anno_list(msk); > @@ -2882,6 +2860,8 @@ static void mptcp_release_cb(struct sock *sk) > flags |= BIT(MPTCP_PUSH_PENDING); > if (test_and_clear_bit(MPTCP_RETRANSMIT, &mptcp_sk(sk)->flags)) > flags |= BIT(MPTCP_RETRANSMIT); > + if (test_and_clear_bit(MPTCP_DEQUEUE, &mptcp_sk(sk)->flags)) > + flags |= BIT(MPTCP_DEQUEUE); > if (!flags) > break; > > @@ -2898,6 +2878,8 @@ static void mptcp_release_cb(struct sock *sk) > __mptcp_push_pending(sk, 0); > if (flags & BIT(MPTCP_RETRANSMIT)) > __mptcp_retrans(sk); > + if ((flags & BIT(MPTCP_DEQUEUE)) && __mptcp_move_skbs(sk)) > + sk->sk_data_ready(sk); > > cond_resched(); > spin_lock_bh(&sk->sk_lock.slock); > diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h > index 2f22046a7565..d392ee44deb3 100644 > --- a/net/mptcp/protocol.h > +++ b/net/mptcp/protocol.h > @@ -111,6 +111,7 @@ > #define MPTCP_ERROR_REPORT 8 > #define MPTCP_RETRANSMIT 9 > #define MPTCP_WORK_SYNC_SETSOCKOPT 10 > +#define MPTCP_DEQUEUE 11 > > static inline bool before64(__u64 seq1, __u64 seq2) > { > @@ -244,7 +245,6 @@ struct mptcp_sock { > struct work_struct work; > struct sk_buff *ooo_last_skb; > struct rb_root out_of_order_queue; > - struct sk_buff_head receive_queue; > int tx_pending_data; > int size_goal_cache; > struct list_head conn_list; > -- > 2.26.3 > > > -- Mat Martineau Intel
On Tue, 2021-05-25 at 17:06 -0700, Mat Martineau wrote: > On Tue, 25 May 2021, Paolo Abeni wrote: > > > After commit c2e6048fa1cf ("mptcp: fix race in release_cb") it's > > pretty straight forward move the whole MPTCP rx path under the socket > > lock leveraging the release_cb. > > > > We can drop a bunch of spin_lock pairs in the receive functions, use > > a single receive queue and invoke __mptcp_move_skbs only when subflows > > ask for it. > > > > This will allow more cleanup in the next patch > > > > Like you said in the cover letter, the perf data will really help with > understanding the performance tradeoff. > > I'm a little paranoid about the locking changes, since the > mptcp_data_lock() is used to protect several things. What do you think > about a debug patch (maybe temporarily in the export branch, but not > upstreamed) that used spin_is_locked() or assert_spin_locked() to double > check that there's still lock coverage where we expect it? I thought about that. The "problem" is that the relevant lockdep assertion is 'lockdep_sock_is_held()' which is both quite simple to verify with code inspection only and not very accurate: lockdep_sock_is_held() can be true and the caller can be without the appropriate lock e.g. if lockdep_is_held(&sk->sk_lock.slock) and sk- >sk_lock.owned by someonelse. TL;DR: lock assertion can be added, but very likely with little value. Please let me know if I should add it in the next iteration. On the flip/positive side, I keep this thing running for the whole WE without any issue ;) Thanks! Paolo
diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c index 6050431f4c86..57deea409d0c 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -682,11 +682,6 @@ static bool move_skbs_to_msk(struct mptcp_sock *msk, struct sock *ssk) struct sock *sk = (struct sock *)msk; unsigned int moved = 0; - if (inet_sk_state_load(sk) == TCP_CLOSE) - return; - - mptcp_data_lock(sk); - __mptcp_move_skbs_from_subflow(msk, ssk, &moved); __mptcp_ofo_queue(msk); @@ -697,12 +692,11 @@ static bool move_skbs_to_msk(struct mptcp_sock *msk, struct sock *ssk) */ if (mptcp_pending_data_fin(sk, NULL)) mptcp_schedule_work(sk); - mptcp_data_unlock(sk); return moved > 0; } -void mptcp_data_ready(struct sock *sk, struct sock *ssk) +static void __mptcp_data_ready(struct sock *sk, struct sock *ssk) { struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk); struct mptcp_sock *msk = mptcp_sk(sk); @@ -731,6 +725,16 @@ void mptcp_data_ready(struct sock *sk, struct sock *ssk) } } +void mptcp_data_ready(struct sock *sk, struct sock *ssk) +{ + mptcp_data_lock(sk); + if (!sock_owned_by_user(sk)) + __mptcp_data_ready(sk, ssk); + else + set_bit(MPTCP_DEQUEUE, &mptcp_sk(sk)->flags); + mptcp_data_unlock(sk); +} + static bool mptcp_do_flush_join_list(struct mptcp_sock *msk) { struct mptcp_subflow_context *subflow; @@ -967,7 +971,6 @@ static bool mptcp_wmem_alloc(struct sock *sk, int size) if (msk->wmem_reserved >= size) goto account; - mptcp_data_lock(sk); if (!sk_wmem_schedule(sk, size)) { mptcp_data_unlock(sk); return false; @@ -975,7 +978,6 @@ static bool mptcp_wmem_alloc(struct sock *sk, int size) sk->sk_forward_alloc -= size; msk->wmem_reserved += size; - mptcp_data_unlock(sk); account: msk->wmem_reserved -= size; @@ -1002,12 +1004,10 @@ static void mptcp_mem_reclaim_partial(struct sock *sk) if (msk->wmem_reserved < 0) return; - mptcp_data_lock(sk); sk->sk_forward_alloc += msk->wmem_reserved; sk_mem_reclaim_partial(sk); msk->wmem_reserved = sk->sk_forward_alloc; sk->sk_forward_alloc = 0; - mptcp_data_unlock(sk); } static void dfrag_uncharge(struct sock *sk, int len) @@ -1092,9 +1092,7 @@ static void __mptcp_clean_una_wakeup(struct sock *sk) static void mptcp_clean_una_wakeup(struct sock *sk) { - mptcp_data_lock(sk); __mptcp_clean_una_wakeup(sk); - mptcp_data_unlock(sk); } static void mptcp_enter_memory_pressure(struct sock *sk) @@ -1713,16 +1711,22 @@ static void mptcp_wait_data(struct sock *sk, long *timeo) remove_wait_queue(sk_sleep(sk), &wait); } -static int __mptcp_recvmsg_mskq(struct mptcp_sock *msk, +static bool __mptcp_move_skbs(struct sock *sk); + +static int __mptcp_recvmsg_mskq(struct sock *sk, struct msghdr *msg, size_t len, int flags, struct scm_timestamping_internal *tss, int *cmsg_flags) { + struct mptcp_sock *msk = mptcp_sk(sk); struct sk_buff *skb, *tmp; int copied = 0; - skb_queue_walk_safe(&msk->receive_queue, skb, tmp) { + if (skb_queue_empty(&sk->sk_receive_queue) && !__mptcp_move_skbs(sk)) + return 0; + + skb_queue_walk_safe(&sk->sk_receive_queue, skb, tmp) { u32 offset = MPTCP_SKB_CB(skb)->offset; u32 data_len = skb->len - offset; u32 count = min_t(size_t, len - copied, data_len); @@ -1754,7 +1758,7 @@ static int __mptcp_recvmsg_mskq(struct mptcp_sock *msk, /* we will bulk release the skb memory later */ skb->destructor = NULL; msk->rmem_released += skb->truesize; - __skb_unlink(skb, &msk->receive_queue); + __skb_unlink(skb, &sk->sk_receive_queue); __kfree_skb(skb); } @@ -1875,16 +1879,9 @@ static void __mptcp_update_rmem(struct sock *sk) msk->rmem_released = 0; } -static void __mptcp_splice_receive_queue(struct sock *sk) +static bool __mptcp_move_skbs(struct sock *sk) { struct mptcp_sock *msk = mptcp_sk(sk); - - skb_queue_splice_tail_init(&sk->sk_receive_queue, &msk->receive_queue); -} - -static bool __mptcp_move_skbs(struct mptcp_sock *msk) -{ - struct sock *sk = (struct sock *)msk; unsigned int moved = 0; bool ret, done; @@ -1893,18 +1890,12 @@ static bool __mptcp_move_skbs(struct mptcp_sock *msk) struct sock *ssk = mptcp_subflow_recv_lookup(msk); bool slowpath; - /* we can have data pending in the subflows only if the msk - * receive buffer was full at subflow_data_ready() time, - * that is an unlikely slow path. - */ - if (likely(!ssk)) + if (unlikely(!ssk)) break; slowpath = lock_sock_fast(ssk); - mptcp_data_lock(sk); __mptcp_update_rmem(sk); done = __mptcp_move_skbs_from_subflow(msk, ssk, &moved); - mptcp_data_unlock(sk); tcp_cleanup_rbuf(ssk, moved); unlock_sock_fast(ssk, slowpath); } while (!done); @@ -1912,17 +1903,16 @@ static bool __mptcp_move_skbs(struct mptcp_sock *msk) /* acquire the data lock only if some input data is pending */ ret = moved > 0; if (!RB_EMPTY_ROOT(&msk->out_of_order_queue) || - !skb_queue_empty_lockless(&sk->sk_receive_queue)) { - mptcp_data_lock(sk); + !skb_queue_empty(&sk->sk_receive_queue)) { __mptcp_update_rmem(sk); ret |= __mptcp_ofo_queue(msk); - __mptcp_splice_receive_queue(sk); - mptcp_data_unlock(sk); mptcp_cleanup_rbuf(msk); } - if (ret) + if (ret) { + set_bit(MPTCP_DATA_READY, &msk->flags); mptcp_check_data_fin((struct sock *)msk); - return !skb_queue_empty(&msk->receive_queue); + } + return ret; } static int mptcp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, @@ -1938,7 +1928,7 @@ static int mptcp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, if (unlikely(flags & MSG_ERRQUEUE)) return inet_recv_error(sk, msg, len, addr_len); - mptcp_lock_sock(sk, __mptcp_splice_receive_queue(sk)); + lock_sock(sk); if (unlikely(sk->sk_state == TCP_LISTEN)) { copied = -ENOTCONN; goto out_err; @@ -1952,7 +1942,7 @@ static int mptcp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, while (copied < len) { int bytes_read; - bytes_read = __mptcp_recvmsg_mskq(msk, msg, len - copied, flags, &tss, &cmsg_flags); + bytes_read = __mptcp_recvmsg_mskq(sk, msg, len - copied, flags, &tss, &cmsg_flags); if (unlikely(bytes_read < 0)) { if (!copied) copied = bytes_read; @@ -1964,9 +1954,6 @@ static int mptcp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, /* be sure to advertise window change */ mptcp_cleanup_rbuf(msk); - if (skb_queue_empty(&msk->receive_queue) && __mptcp_move_skbs(msk)) - continue; - /* only the master socket status is relevant here. The exit * conditions mirror closely tcp_recvmsg() */ @@ -1993,7 +1980,7 @@ static int mptcp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, /* race breaker: the shutdown could be after the * previous receive queue check */ - if (__mptcp_move_skbs(msk)) + if (__mptcp_move_skbs(sk)) continue; break; } @@ -2018,16 +2005,11 @@ static int mptcp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, mptcp_wait_data(sk, &timeo); } - if (skb_queue_empty_lockless(&sk->sk_receive_queue) && - skb_queue_empty(&msk->receive_queue)) { - /* entire backlog drained, clear DATA_READY. */ - clear_bit(MPTCP_DATA_READY, &msk->flags); - - /* .. race-breaker: ssk might have gotten new data - * after last __mptcp_move_skbs() returned false. + if (skb_queue_empty(&sk->sk_receive_queue)) { + /* entire backlog drained, clear DATA_READY. + * release_cb/__mptcp_move_skbs() will eventually set it again if needed */ - if (unlikely(__mptcp_move_skbs(msk))) - set_bit(MPTCP_DATA_READY, &msk->flags); + clear_bit(MPTCP_DATA_READY, &msk->flags); } out_err: @@ -2376,7 +2358,6 @@ static int __mptcp_init_sock(struct sock *sk) INIT_LIST_HEAD(&msk->join_list); INIT_LIST_HEAD(&msk->rtx_queue); INIT_WORK(&msk->work, mptcp_worker); - __skb_queue_head_init(&msk->receive_queue); msk->out_of_order_queue = RB_ROOT; msk->first_pending = NULL; msk->wmem_reserved = 0; @@ -2828,9 +2809,6 @@ void mptcp_destroy_common(struct mptcp_sock *msk) __mptcp_clear_xmit(sk); - /* move to sk_receive_queue, sk_stream_kill_queues will purge it */ - skb_queue_splice_tail_init(&msk->receive_queue, &sk->sk_receive_queue); - skb_rbtree_purge(&msk->out_of_order_queue); mptcp_token_destroy(msk); mptcp_pm_free_anno_list(msk); @@ -2882,6 +2860,8 @@ static void mptcp_release_cb(struct sock *sk) flags |= BIT(MPTCP_PUSH_PENDING); if (test_and_clear_bit(MPTCP_RETRANSMIT, &mptcp_sk(sk)->flags)) flags |= BIT(MPTCP_RETRANSMIT); + if (test_and_clear_bit(MPTCP_DEQUEUE, &mptcp_sk(sk)->flags)) + flags |= BIT(MPTCP_DEQUEUE); if (!flags) break; @@ -2898,6 +2878,8 @@ static void mptcp_release_cb(struct sock *sk) __mptcp_push_pending(sk, 0); if (flags & BIT(MPTCP_RETRANSMIT)) __mptcp_retrans(sk); + if ((flags & BIT(MPTCP_DEQUEUE)) && __mptcp_move_skbs(sk)) + sk->sk_data_ready(sk); cond_resched(); spin_lock_bh(&sk->sk_lock.slock); diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h index 2f22046a7565..d392ee44deb3 100644 --- a/net/mptcp/protocol.h +++ b/net/mptcp/protocol.h @@ -111,6 +111,7 @@ #define MPTCP_ERROR_REPORT 8 #define MPTCP_RETRANSMIT 9 #define MPTCP_WORK_SYNC_SETSOCKOPT 10 +#define MPTCP_DEQUEUE 11 static inline bool before64(__u64 seq1, __u64 seq2) { @@ -244,7 +245,6 @@ struct mptcp_sock { struct work_struct work; struct sk_buff *ooo_last_skb; struct rb_root out_of_order_queue; - struct sk_buff_head receive_queue; int tx_pending_data; int size_goal_cache; struct list_head conn_list;
After commit c2e6048fa1cf ("mptcp: fix race in release_cb") it's pretty straight forward move the whole MPTCP rx path under the socket lock leveraging the release_cb. We can drop a bunch of spin_lock pairs in the receive functions, use a single receive queue and invoke __mptcp_move_skbs only when subflows ask for it. This will allow more cleanup in the next patch Signed-off-by: Paolo Abeni <pabeni@redhat.com> --- net/mptcp/protocol.c | 94 ++++++++++++++++++-------------------------- net/mptcp/protocol.h | 2 +- 2 files changed, 39 insertions(+), 57 deletions(-)