diff mbox

[NETMAP,12/12] linux-netmap: pktio: poll only when needed

Message ID 1425322017-14636-13-git-send-email-ciprian.barbu@linaro.org
State New
Headers show

Commit Message

Ciprian Barbu March 2, 2015, 6:46 p.m. UTC 
Calling poll each time in send and recv routines has its cost, calling poll only
when needed gives a better performance with the cost of possibly losing some
frames on the TX side.

Signed-off-by: Ciprian Barbu <ciprian.barbu@linaro.org>
---
 platform/linux-netmap/odp_packet_netmap.c | 26 ++++++++++++++------------
 1 file changed, 14 insertions(+), 12 deletions(-)
diff mbox

Patch

diff --git a/platform/linux-netmap/odp_packet_netmap.c b/platform/linux-netmap/odp_packet_netmap.c
index 8e68d34..50062ea 100644
--- a/platform/linux-netmap/odp_packet_netmap.c
+++ b/platform/linux-netmap/odp_packet_netmap.c
@@ -318,13 +318,14 @@  int recv_pkt_netmap(pkt_netmap_t * const pkt_nm, odp_packet_t pkt_table[],
 	args.pkt_nm = pkt_nm;
 
 	odp_ticketlock_lock(&pkt_nm->nm_dev->rx_lock);
-	ret = poll(fds, 1, POLL_TMO);
-	if (ret <= 0 || (fds[0].revents & POLLERR)) {
-		odp_ticketlock_unlock(&pkt_nm->nm_dev->rx_lock);
-		return 0;
-	}
-
 	nm_dispatch(pkt_nm->desc, len, nm_recv_cb, (uint8_t *)&args);
+	if (args.nb_rx == 0) {
+		ret = poll(fds, 1, POLL_TMO);
+		if (ret <= 0 || (fds[0].revents & POLLERR)) {
+			odp_ticketlock_unlock(&pkt_nm->nm_dev->rx_lock);
+			return 0;
+		}
+	}
 	odp_ticketlock_unlock(&pkt_nm->nm_dev->rx_lock);
 
 	return args.nb_rx;
@@ -342,12 +343,6 @@  int send_pkt_netmap(pkt_netmap_t * const pkt_nm, odp_packet_t pkt_table[],
 	fds[0].events = POLLOUT;
 
 	odp_ticketlock_lock(&pkt_nm->nm_dev->tx_lock);
-	ret = poll(fds, 1, POLL_TMO);
-	if (ret <= 0 || (fds[0].revents & POLLERR)) {
-		odp_ticketlock_unlock(&pkt_nm->nm_dev->tx_lock);
-		goto out;
-	}
-
 	for (nb_tx = 0; nb_tx < len; nb_tx++) {
 		odp_packet_t pkt = pkt_table[nb_tx];
 		uint8_t *frame = odp_packet_l2(pkt);
@@ -355,6 +350,13 @@  int send_pkt_netmap(pkt_netmap_t * const pkt_nm, odp_packet_t pkt_table[],
 		if (nm_inject(pkt_nm->desc, frame, frame_len) == 0)
 			break;
 	}
+	if (nb_tx == 0) {
+		ret = poll(fds, 1, POLL_TMO);
+		if (ret <= 0 || (fds[0].revents & POLLERR)) {
+			odp_ticketlock_unlock(&pkt_nm->nm_dev->tx_lock);
+			goto out;
+		}
+	}
 	odp_ticketlock_unlock(&pkt_nm->nm_dev->tx_lock);
 
 out: