kni application have two main-loop threads that they
CPU utilization are up to 100 percent, this two theads are
writing thread and reading thread. I thank set interrupt mode
at reading thread would reduce this thread CPU utilization.
Signed-off-by: Tianli Lai <laitia...@tom.com>
---
examples/kni/main.c | 91 +++++++++++++++++++++++++++++++++++++++++----
1 file changed, 84 insertions(+), 7 deletions(-)
diff --git a/examples/kni/main.c b/examples/kni/main.c
index e99ef5c38a..d4d7a3daa9 100644
--- a/examples/kni/main.c
+++ b/examples/kni/main.c
@@ -73,6 +73,7 @@
#define KNI_US_PER_SECOND 1000000
#define KNI_SECOND_PER_DAY 86400
+#define MIN_ZERO_POLL_COUNT 100
#define KNI_MAX_KTHREAD 32
/*
@@ -107,6 +108,8 @@ static uint32_t ports_mask = 0;
static int promiscuous_on = 0;
/* Monitor link status continually. off by default. */
static int monitor_links;
+/* rx set in interrupt mode off by default. */
+static int intr_rx_en;
/* Structure type for recording kni interface specific stats */
struct kni_interface_stats {
@@ -206,7 +209,7 @@ kni_burst_free_mbufs(struct rte_mbuf **pkts, unsigned num)
/**
* Interface to burst rx and enqueue mbufs into rx_q
*/
-static void
+static int
kni_ingress(struct kni_port_params *p)
{
uint8_t i;
@@ -214,9 +217,9 @@ kni_ingress(struct kni_port_params *p)
unsigned nb_rx, num;
uint32_t nb_kni;
struct rte_mbuf *pkts_burst[PKT_BURST_SZ];
-
+ int ret = 0;
if (p == NULL)
- return;
+ return -1;
nb_kni = p->nb_kni;
port_id = p->port_id;
@@ -225,8 +228,10 @@ kni_ingress(struct kni_port_params *p)
nb_rx = rte_eth_rx_burst(port_id, 0, pkts_burst, PKT_BURST_SZ);
if (unlikely(nb_rx > PKT_BURST_SZ)) {
RTE_LOG(ERR, APP, "Error receiving from eth\n");
- return;
+ return -1;
}
+ if (nb_rx == 0)
+ ret = 1;
/* Burst tx to kni */
num = rte_kni_tx_burst(p->kni[i], pkts_burst, nb_rx);
if (num)
@@ -239,6 +244,7 @@ kni_ingress(struct kni_port_params *p)
kni_stats[port_id].rx_dropped += nb_rx - num;
}
}
+ return ret;
}
/**
@@ -277,12 +283,56 @@ kni_egress(struct kni_port_params *p)
}
}
+static int
+sleep_until_rx_interrupt(int num, int lcore)
+{
+ static struct {
+ bool wakeup;
+ } __rte_cache_aligned status[RTE_MAX_LCORE];
+ struct rte_epoll_event event[num];
+ int n;
+
+ if (status[lcore].wakeup) {
+ RTE_LOG(DEBUG, APP,
+ "lcore %u sleeps until interrupt triggers\n",
+ rte_lcore_id());
+ }
+ n = rte_epoll_wait(RTE_EPOLL_PER_THREAD, event, num, 10);
+ status[lcore].wakeup = n != 0;
+
+ return 0;
+}
+
+static void
+turn_on_off_intr(uint16_t port_id, uint16_t queue_id, bool on)
+{
+ if (on)
+ rte_eth_dev_rx_intr_enable(port_id, queue_id);
+ else
+ rte_eth_dev_rx_intr_disable(port_id, queue_id);
+}
+
+static int event_register(void)
+{
+ int ret;
+
+ ret = rte_eth_dev_rx_intr_ctl_q(0, 0,
+ RTE_EPOLL_PER_THREAD,
+ RTE_INTR_EVENT_ADD, NULL);
+ if (ret)
+ return ret;
+
+ return 0;
+}
+
static int
main_loop(__rte_unused void *arg)
{
uint16_t i;
int32_t f_stop;
int32_t f_pause;
+ int ret = 0;
+ uint32_t zero_rx_packet_count = 0;
const unsigned lcore_id = rte_lcore_id();
enum lcore_rxtx {
LCORE_NONE,
@@ -291,12 +341,17 @@ main_loop(__rte_unused void *arg)
LCORE_MAX
};
enum lcore_rxtx flag = LCORE_NONE;
+ int intr_en = 0;
RTE_ETH_FOREACH_DEV(i) {
if (!kni_port_params_array[i])
continue;
if (kni_port_params_array[i]->lcore_rx == (uint8_t)lcore_id) {
flag = LCORE_RX;
+ if (intr_rx_en && !event_register())
+ intr_en = 1;
+ else
+ RTE_LOG(DEBUG, APP, "RX interrupt won't
enable.\n");
break;
} else if (kni_port_params_array[i]->lcore_tx ==
(uint8_t)lcore_id) {
@@ -316,7 +371,23 @@ main_loop(__rte_unused void *arg)
break;
if (f_pause)
continue;
- kni_ingress(kni_port_params_array[i]);
+ ret = kni_ingress(kni_port_params_array[i]);
+ if (ret == 1) {
+ zero_rx_packet_count++;
+ if (zero_rx_packet_count <=
+ MIN_ZERO_POLL_COUNT)
+ continue;
+ } else
+ zero_rx_packet_count = 0;
+
+ if (zero_rx_packet_count > 0) {
+ zero_rx_packet_count = 0;
+ if (unlikely(intr_en)) {
+ turn_on_off_intr(i, 0, 1);
+ sleep_until_rx_interrupt(1, lcore_id);
+ turn_on_off_intr(i, 0, 0);
+ }
+ }
}
} else if (flag == LCORE_TX) {
RTE_LOG(INFO, APP, "Lcore %u is writing to port %d\n",
@@ -341,12 +412,13 @@ main_loop(__rte_unused void *arg)
static void
print_usage(const char *prgname)
{
- RTE_LOG(INFO, APP, "\nUsage: %s [EAL options] -- -p PORTMASK -P -m "
+ RTE_LOG(INFO, APP, "\nUsage: %s [EAL options] -- -p PORTMASK -P -m -I "
"[--config (port,lcore_rx,lcore_tx,lcore_kthread...)"
"[,(port,lcore_rx,lcore_tx,lcore_kthread...)]]\n"
" -p PORTMASK: hex bitmask of ports to use\n"
" -P : enable promiscuous mode\n"
" -m : enable monitoring of port carrier state\n"
+ " -I : enable rx interrupt mode\n"
" --config (port,lcore_rx,lcore_tx,lcore_kthread...): "
"port and lcore configurations\n",
prgname);
@@ -527,7 +599,7 @@ parse_args(int argc, char **argv)
opterr = 0;
/* Parse command line */
- while ((opt = getopt_long(argc, argv, "p:Pm", longopts,
+ while ((opt = getopt_long(argc, argv, "p:PmI", longopts,
&longindex)) != EOF) {
switch (opt) {
case 'p':
@@ -539,6 +611,9 @@ parse_args(int argc, char **argv)
case 'm':
monitor_links = 1;
break;
+ case 'I':
+ intr_rx_en = 1;
+ break;
case 0:
if (!strncmp(longopts[longindex].name,
CMDLINE_OPT_CONFIG,
@@ -610,6 +685,8 @@ init_port(uint16_t port)
if (dev_info.tx_offload_capa & RTE_ETH_TX_OFFLOAD_MBUF_FAST_FREE)
local_port_conf.txmode.offloads |=
RTE_ETH_TX_OFFLOAD_MBUF_FAST_FREE;
+ if (intr_rx_en)
+ local_port_conf.intr_conf.rxq = 1;
ret = rte_eth_dev_configure(port, 1, 1, &local_port_conf);
if (ret < 0)
rte_exit(EXIT_FAILURE, "Could not configure port%u (%d)\n",
--
2.27.0
