[dpdk-dev] [PATCH] app/testpmd: fix little perf drop with XL710

[Xiaoyun Li <xiaoyun.li@intel.com>]

There is about 1.8M perf drop with XL710. And it is because of a
bitrate calculation in the datapath. So improve it by maintaining
an array of port indexes in testpmd, which is updated with ethdev
events.

Fixes: 8728ccf37615 ("fix ethdev ports enumeration")
Cc: stable@dpdk.org

Signed-off-by: Xiaoyun Li <xiaoyun.li@intel.com>
---
 app/test-pmd/testpmd.c | 36 ++++++++++++++++++++++++++++++++----
 1 file changed, 32 insertions(+), 4 deletions(-)

diff --git a/app/test-pmd/testpmd.c b/app/test-pmd/testpmd.c
index 24c1998..0600806 100644
--- a/app/test-pmd/testpmd.c
+++ b/app/test-pmd/testpmd.c
@@ -127,6 +127,8 @@ portid_t nb_ports;             /**< Number of probed ethernet ports. */
 struct fwd_lcore **fwd_lcores; /**< For all probed logical cores. */
 lcoreid_t nb_lcores;           /**< Number of probed logical cores. */
 
+portid_t ports_ids[RTE_MAX_ETHPORTS]; /**< Store all port ids. */
+
 /*
  * Test Forwarding Configuration.
  *    nb_fwd_lcores <= nb_cfg_lcores <= nb_lcores
@@ -1148,8 +1150,9 @@ run_pkt_fwd_on_lcore(struct fwd_lcore *fc, packet_fwd_t pkt_fwd)
 	uint64_t tics_per_1sec;
 	uint64_t tics_datum;
 	uint64_t tics_current;
-	uint16_t idx_port;
+	uint16_t i, cnt_ports;
 
+	cnt_ports = nb_ports;
 	tics_datum = rte_rdtsc();
 	tics_per_1sec = rte_get_timer_hz();
 #endif
@@ -1164,9 +1167,9 @@ run_pkt_fwd_on_lcore(struct fwd_lcore *fc, packet_fwd_t pkt_fwd)
 			tics_current = rte_rdtsc();
 			if (tics_current - tics_datum >= tics_per_1sec) {
 				/* Periodic bitrate calculation */
-				RTE_ETH_FOREACH_DEV(idx_port)
+				for (i = 0; i < cnt_ports; i++)
 					rte_stats_bitrate_calc(bitrate_data,
-						idx_port);
+						ports_ids[i]);
 				tics_datum = tics_current;
 			}
 		}
@@ -2196,16 +2199,31 @@ static void
 eth_dev_event_callback(char *device_name, enum rte_dev_event_type type,
 			     __rte_unused void *arg)
 {
+	portid_t port_id;
+	uint16_t i;
+
 	if (type >= RTE_DEV_EVENT_MAX) {
 		fprintf(stderr, "%s called upon invalid event %d\n",
 			__func__, type);
 		fflush(stderr);
 	}
 
+	rte_eth_dev_get_port_by_name(device_name, &port_id);
+
 	switch (type) {
 	case RTE_DEV_EVENT_REMOVE:
 		RTE_LOG(ERR, EAL, "The device: %s has been removed!\n",
 			device_name);
+
+		for (i = 0; i < nb_ports; i++) {
+			if (ports_ids[i] == port_id) {
+				ports_ids[i] = ports_ids[nb_ports-1];
+				ports_ids[nb_ports-1] = 0;
+				nb_ports--;
+				break;
+			}
+		}
+
 		/* TODO: After finish failure handle, begin to stop
 		 * packet forward, stop port, close port, detach port.
 		 */
@@ -2213,6 +2231,10 @@ eth_dev_event_callback(char *device_name, enum rte_dev_event_type type,
 	case RTE_DEV_EVENT_ADD:
 		RTE_LOG(ERR, EAL, "The device: %s has been added!\n",
 			device_name);
+
+		ports_ids[nb_ports] = port_id;
+		nb_ports++;
+
 		/* TODO: After finish kernel driver binding,
 		 * begin to attach port.
 		 */
@@ -2652,6 +2674,7 @@ main(int argc, char** argv)
 {
 	int diag;
 	portid_t port_id;
+	uint16_t count;
 	int ret;
 
 	signal(SIGINT, signal_handler);
@@ -2671,7 +2694,12 @@ main(int argc, char** argv)
 	rte_pdump_init(NULL);
 #endif
 
-	nb_ports = (portid_t) rte_eth_dev_count_avail();
+	count = 0;
+	RTE_ETH_FOREACH_DEV(port_id) {
+		ports_ids[count] = port_id;
+		count++;
+	}
+	nb_ports = (portid_t) count;
 	if (nb_ports == 0)
 		TESTPMD_LOG(WARNING, "No probed ethernet devices\n");
 
-- 
2.7.4