This commit introduces line rate limiting using a token passing method.
The target traffic rate default is currently hard coded, this can be set
using telemetry.
Signed-off-by: Ronan Randles <ronan.randles@intel.com>
---
examples/generator/main.c | 79 +++++++++++++++++++++++++--------------
1 file changed, 51 insertions(+), 28 deletions(-)
@@ -40,6 +40,7 @@ struct rte_gen *gen;
struct gen_args {
/* Inputs */
struct rte_gen *gen;
+ uint64_t target_tx_pps;
/* Outputs */
uint64_t tx_total_packets;
@@ -195,7 +196,6 @@ gen_wait_for_links_up(void)
rte_delay_us_block(100);
}
}
-
/* The lcore main. This is the main thread that does the work, reading from
* an input port and writing to an output port.
*/
@@ -217,43 +217,63 @@ lcore_producer(void *arg)
"not be optimal.\n", port);
uint64_t tsc_hz = rte_get_tsc_hz();
+ float tsc_hz_f = (float)tsc_hz;
uint64_t last_tsc_reading = 0;
uint64_t last_tx_total = 0;
uint16_t nb_tx = 0;
+ float tokens = 0;
/* Wait for links to come up before generating packets */
gen_wait_for_links_up();
if (!done)
printf("Generating packets...\n");
+ uint64_t token_last_add_tsc = rte_rdtsc();
+
/* Run until the application is quit or killed. */
while (!done) {
-
struct rte_mbuf *bufs[BURST_SIZE];
- /* Receive packets from gen and then tx them over port */
-
- RTE_ETH_FOREACH_DEV(port) {
- int nb_generated = rte_gen_rx_burst(gen, bufs,
- BURST_SIZE);
-
- uint64_t start_tsc = rte_rdtsc();
- if (start_tsc > last_tsc_reading + tsc_hz) {
- args->measured_tx_pps = args->tx_total_packets -
- last_tx_total;
- last_tx_total = args->tx_total_packets;
- last_tsc_reading = start_tsc;
+ /* Track time since last token add and calculate number
+ * of tokens to give per second to implement line rate limiting
+ */
+ uint64_t now = rte_rdtsc();
+ uint64_t tsc_delta = now - token_last_add_tsc;
+ float token_scalar = (float)tsc_delta / tsc_hz_f;
+ float add_tokens = args->target_tx_pps * token_scalar;
+ /* If there are tokens to be added and we haven't exceeded
+ * the target rate then we add tokens
+ */
+ if (add_tokens > 1.f) {
+ if (tokens < args->target_tx_pps) {
+ tokens += add_tokens;
+ token_last_add_tsc = now;
}
- nb_tx = rte_eth_tx_burst(port, 0, bufs, nb_generated);
- args->tx_total_packets += nb_tx;
-
- uint64_t tx_failed = nb_generated - nb_tx;
- if (nb_tx != nb_generated) {
- rte_pktmbuf_free_bulk(&bufs[nb_tx], tx_failed);
- args->tx_failed += tx_failed;
+ }
+ /* Receive packets from gen and then tx them over port */
+ if (tokens >= BURST_SIZE) {
+ RTE_ETH_FOREACH_DEV(port) {
+ int nb_generated = rte_gen_rx_burst(gen, bufs,
+ BURST_SIZE);
+
+ uint64_t start_tsc = rte_rdtsc();
+ if (start_tsc > last_tsc_reading + tsc_hz) {
+ args->measured_tx_pps =
+ args->tx_total_packets - last_tx_total;
+ last_tx_total = args->tx_total_packets;
+ last_tsc_reading = start_tsc;
+ }
+ nb_tx = rte_eth_tx_burst(port, 0, bufs,
+ nb_generated);
+ args->tx_total_packets += nb_tx;
+ tokens -= nb_tx;
+
+ uint64_t tx_failed = nb_generated - nb_tx;
+ if (nb_tx != nb_generated) {
+ rte_pktmbuf_free_bulk(&bufs[nb_tx],
+ tx_failed);
+ args->tx_failed += tx_failed;
+ }
}
- if (unlikely(nb_tx == 0))
- continue;
-
}
}
return 0;
@@ -296,7 +316,6 @@ lcore_consumer(void *arg)
BURST_SIZE);
if (unlikely(nb_rx == 0))
continue;
-
args->rx_total_packets += nb_rx;
int nb_sent = rte_gen_tx_burst(gen, bufs,
@@ -320,12 +339,14 @@ static int
tele_gen_mpps(const char *cmd, const char *params, struct rte_tel_data *d)
{
RTE_SET_USED(cmd);
- RTE_SET_USED(params);
struct gen_args *args = telemetry_userdata.prod;
+ if (params) {
+ args->target_tx_pps = atoi(params) * 1000000;
+ printf("Packet rate set: %li\n", args->target_tx_pps);
+ }
rte_tel_data_start_dict(d);
- rte_tel_data_add_dict_int(d, "pps",
- (args->measured_tx_pps));
+ rte_tel_data_add_dict_int(d, "pps", args->target_tx_pps);
return 0;
}
@@ -412,6 +433,8 @@ main(int argc, char *argv[])
if (lcore_count == 0) {
telemetry_userdata.prod =
&core_launch_args[lcore_count];
+ /* Default traffic rate */
+ telemetry_userdata.prod->target_tx_pps = 20000000;
rte_eal_remote_launch(lcore_producer,
telemetry_userdata.prod,
lcore_id);