From de8474eb9d50fd47b8c73816f34739dec5e96754 Mon Sep 17 00:00:00 2001 From: Stefan Raspl Date: Wed, 23 May 2018 16:38:11 +0200 Subject: net/smc: urgent data support Add support for out of band data send and receive. Signed-off-by: Stefan Raspl Signed-off-by: Ursula Braun Signed-off-by: David S. Miller --- net/smc/smc_tx.c | 55 ++++++++++++++++++++++++++++++++++++++----------------- 1 file changed, 38 insertions(+), 17 deletions(-) (limited to 'net/smc/smc_tx.c') diff --git a/net/smc/smc_tx.c b/net/smc/smc_tx.c index 1f4a38b857f0..cee666400752 100644 --- a/net/smc/smc_tx.c +++ b/net/smc/smc_tx.c @@ -32,7 +32,7 @@ /***************************** sndbuf producer *******************************/ /* callback implementation for sk.sk_write_space() - * to wakeup sndbuf producers that blocked with smc_tx_wait_memory(). + * to wakeup sndbuf producers that blocked with smc_tx_wait(). * called under sk_socket lock. */ static void smc_tx_write_space(struct sock *sk) @@ -56,7 +56,7 @@ static void smc_tx_write_space(struct sock *sk) } } -/* Wakeup sndbuf producers that blocked with smc_tx_wait_memory(). +/* Wakeup sndbuf producers that blocked with smc_tx_wait(). * Cf. tcp_data_snd_check()=>tcp_check_space()=>tcp_new_space(). */ void smc_tx_sndbuf_nonfull(struct smc_sock *smc) @@ -66,8 +66,10 @@ void smc_tx_sndbuf_nonfull(struct smc_sock *smc) smc->sk.sk_write_space(&smc->sk); } -/* blocks sndbuf producer until at least one byte of free space available */ -static int smc_tx_wait_memory(struct smc_sock *smc, int flags) +/* blocks sndbuf producer until at least one byte of free space available + * or urgent Byte was consumed + */ +static int smc_tx_wait(struct smc_sock *smc, int flags) { DEFINE_WAIT_FUNC(wait, woken_wake_function); struct smc_connection *conn = &smc->conn; @@ -103,14 +105,15 @@ static int smc_tx_wait_memory(struct smc_sock *smc, int flags) break; } sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk); - if (atomic_read(&conn->sndbuf_space)) - break; /* at least 1 byte of free space available */ + if (atomic_read(&conn->sndbuf_space) && !conn->urg_tx_pend) + break; /* at least 1 byte of free & no urgent data */ set_bit(SOCK_NOSPACE, &sk->sk_socket->flags); sk_wait_event(sk, &timeo, sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN) || smc_cdc_rxed_any_close(conn) || - atomic_read(&conn->sndbuf_space), + (atomic_read(&conn->sndbuf_space) && + !conn->urg_tx_pend), &wait); } remove_wait_queue(sk_sleep(sk), &wait); @@ -157,8 +160,11 @@ int smc_tx_sendmsg(struct smc_sock *smc, struct msghdr *msg, size_t len) if (smc_cdc_rxed_any_close(conn)) return send_done ?: -ECONNRESET; - if (!atomic_read(&conn->sndbuf_space)) { - rc = smc_tx_wait_memory(smc, msg->msg_flags); + if (msg->msg_flags & MSG_OOB) + conn->local_tx_ctrl.prod_flags.urg_data_pending = 1; + + if (!atomic_read(&conn->sndbuf_space) || conn->urg_tx_pend) { + rc = smc_tx_wait(smc, msg->msg_flags); if (rc) { if (send_done) return send_done; @@ -168,7 +174,7 @@ int smc_tx_sendmsg(struct smc_sock *smc, struct msghdr *msg, size_t len) } /* initialize variables for 1st iteration of subsequent loop */ - /* could be just 1 byte, even after smc_tx_wait_memory above */ + /* could be just 1 byte, even after smc_tx_wait above */ writespace = atomic_read(&conn->sndbuf_space); /* not more than what user space asked for */ copylen = min_t(size_t, send_remaining, writespace); @@ -218,6 +224,8 @@ int smc_tx_sendmsg(struct smc_sock *smc, struct msghdr *msg, size_t len) /* since we just produced more new data into sndbuf, * trigger sndbuf consumer: RDMA write into peer RMBE and CDC */ + if ((msg->msg_flags & MSG_OOB) && !send_remaining) + conn->urg_tx_pend = true; if ((msg->msg_flags & MSG_MORE || smc_tx_is_corked(smc)) && (atomic_read(&conn->sndbuf_space) > (conn->sndbuf_desc->len >> 1))) @@ -299,6 +307,7 @@ static int smc_tx_rdma_writes(struct smc_connection *conn) union smc_host_cursor sent, prep, prod, cons; struct ib_sge sges[SMC_IB_MAX_SEND_SGE]; struct smc_link_group *lgr = conn->lgr; + struct smc_cdc_producer_flags *pflags; int to_send, rmbespace; struct smc_link *link; dma_addr_t dma_addr; @@ -326,7 +335,8 @@ static int smc_tx_rdma_writes(struct smc_connection *conn) conn); /* if usable snd_wnd closes ask peer to advertise once it opens again */ - conn->local_tx_ctrl.prod_flags.write_blocked = (to_send >= rmbespace); + pflags = &conn->local_tx_ctrl.prod_flags; + pflags->write_blocked = (to_send >= rmbespace); /* cf. usable snd_wnd */ len = min(to_send, rmbespace); @@ -391,6 +401,8 @@ static int smc_tx_rdma_writes(struct smc_connection *conn) src_len_sum = src_len; } + if (conn->urg_tx_pend && len == to_send) + pflags->urg_data_present = 1; smc_tx_advance_cursors(conn, &prod, &sent, len); /* update connection's cursors with advanced local cursors */ smc_curs_write(&conn->local_tx_ctrl.prod, @@ -410,6 +422,7 @@ static int smc_tx_rdma_writes(struct smc_connection *conn) */ int smc_tx_sndbuf_nonempty(struct smc_connection *conn) { + struct smc_cdc_producer_flags *pflags; struct smc_cdc_tx_pend *pend; struct smc_wr_buf *wr_buf; int rc; @@ -433,14 +446,21 @@ int smc_tx_sndbuf_nonempty(struct smc_connection *conn) goto out_unlock; } - rc = smc_tx_rdma_writes(conn); - if (rc) { - smc_wr_tx_put_slot(&conn->lgr->lnk[SMC_SINGLE_LINK], - (struct smc_wr_tx_pend_priv *)pend); - goto out_unlock; + if (!conn->local_tx_ctrl.prod_flags.urg_data_present) { + rc = smc_tx_rdma_writes(conn); + if (rc) { + smc_wr_tx_put_slot(&conn->lgr->lnk[SMC_SINGLE_LINK], + (struct smc_wr_tx_pend_priv *)pend); + goto out_unlock; + } } rc = smc_cdc_msg_send(conn, wr_buf, pend); + pflags = &conn->local_tx_ctrl.prod_flags; + if (!rc && pflags->urg_data_present) { + pflags->urg_data_pending = 0; + pflags->urg_data_present = 0; + } out_unlock: spin_unlock_bh(&conn->send_lock); @@ -473,7 +493,7 @@ out: release_sock(&smc->sk); } -void smc_tx_consumer_update(struct smc_connection *conn) +void smc_tx_consumer_update(struct smc_connection *conn, bool force) { union smc_host_cursor cfed, cons; int to_confirm; @@ -487,6 +507,7 @@ void smc_tx_consumer_update(struct smc_connection *conn) to_confirm = smc_curs_diff(conn->rmb_desc->len, &cfed, &cons); if (conn->local_rx_ctrl.prod_flags.cons_curs_upd_req || + force || ((to_confirm > conn->rmbe_update_limit) && ((to_confirm > (conn->rmb_desc->len / 2)) || conn->local_rx_ctrl.prod_flags.write_blocked))) { -- cgit