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authorStefan Raspl <raspl@linux.ibm.com>2018-05-23 16:38:11 +0200
committerDavid S. Miller <davem@davemloft.net>2018-05-23 16:02:35 -0400
commitde8474eb9d50fd47b8c73816f34739dec5e96754 (patch)
tree4d8c4d02508896fefba4c7172162ebf1b8333798 /net/smc/smc_tx.c
parentb9f227c37071d1115cec791b328b684e2c4ba414 (diff)
net/smc: urgent data support
Add support for out of band data send and receive. Signed-off-by: Stefan Raspl <raspl@linux.ibm.com> Signed-off-by: Ursula Braun <ubraun@linux.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/smc/smc_tx.c')
-rw-r--r--net/smc/smc_tx.c55
1 files changed, 38 insertions, 17 deletions
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))) {