Re: [dpdk-dev] [PATCH v1 5/5] L3fwd-power: enable one-shot rx interrupt and polling/interrupt mode switch

["Liang, Cunming" <cunming.liang@intel.com>]

> -----Original Message-----
> From: dev [mailto:dev-bounces@dpdk.org] On Behalf Of Danny Zhou
> Sent: Wednesday, January 28, 2015 2:51 AM
> To: dev@dpdk.org
> Subject: [dpdk-dev] [PATCH v1 5/5] L3fwd-power: enable one-shot rx interrupt
> and polling/interrupt mode switch
> 
> Signed-off-by: Danny Zhou <danny.zhou@intel.com>
> ---
>  examples/l3fwd-power/main.c | 170
> +++++++++++++++++++++++++++++++++-----------
>  1 file changed, 129 insertions(+), 41 deletions(-)
> 
> diff --git a/examples/l3fwd-power/main.c b/examples/l3fwd-power/main.c
> index f6b55b9..e6e4f55 100644
> --- a/examples/l3fwd-power/main.c
> +++ b/examples/l3fwd-power/main.c
> @@ -75,12 +75,13 @@
>  #include <rte_string_fns.h>
>  #include <rte_timer.h>
>  #include <rte_power.h>
> +#include <rte_eal.h>
> 
>  #define RTE_LOGTYPE_L3FWD_POWER RTE_LOGTYPE_USER1
> 
>  #define MAX_PKT_BURST 32
> 
> -#define MIN_ZERO_POLL_COUNT 5
> +#define MIN_ZERO_POLL_COUNT 10
> 
>  /* around 100ms at 2 Ghz */
>  #define TIMER_RESOLUTION_CYCLES           200000000ULL
> @@ -188,6 +189,9 @@ struct lcore_rx_queue {
>  #define MAX_TX_QUEUE_PER_PORT RTE_MAX_ETHPORTS
>  #define MAX_RX_QUEUE_PER_PORT 128
> 
> +#define MAX_RX_QUEUE_INTERRUPT_PER_PORT 16
> +
> +
>  #define MAX_LCORE_PARAMS 1024
>  struct lcore_params {
>  	uint8_t port_id;
> @@ -214,7 +218,7 @@ static uint16_t nb_lcore_params =
> sizeof(lcore_params_array_default) /
> 
>  static struct rte_eth_conf port_conf = {
>  	.rxmode = {
> -		.mq_mode	= ETH_MQ_RX_RSS,
> +		.mq_mode = ETH_MQ_RX_RSS,
>  		.max_rx_pkt_len = ETHER_MAX_LEN,
>  		.split_hdr_size = 0,
>  		.header_split   = 0, /**< Header Split disabled */
> @@ -226,11 +230,14 @@ static struct rte_eth_conf port_conf = {
>  	.rx_adv_conf = {
>  		.rss_conf = {
>  			.rss_key = NULL,
> -			.rss_hf = ETH_RSS_IP,
> +			.rss_hf = ETH_RSS_UDP,
>  		},
>  	},
>  	.txmode = {
> -		.mq_mode = ETH_DCB_NONE,
> +		.mq_mode = ETH_MQ_TX_NONE,
> +	},
> +	.intr_conf = {
> +		.rxq = 1, /**< rxq interrupt feature enabled */
>  	},
>  };
> 
> @@ -402,19 +409,22 @@ power_timer_cb(__attribute__((unused)) struct
> rte_timer *tim,
>  	/* accumulate total execution time in us when callback is invoked */
>  	sleep_time_ratio = (float)(stats[lcore_id].sleep_time) /
>  					(float)SCALING_PERIOD;
> -
>  	/**
>  	 * check whether need to scale down frequency a step if it sleep a lot.
>  	 */
> -	if (sleep_time_ratio >= SCALING_DOWN_TIME_RATIO_THRESHOLD)
> -		rte_power_freq_down(lcore_id);
> +	if (sleep_time_ratio >= SCALING_DOWN_TIME_RATIO_THRESHOLD) {
> +		if (rte_power_freq_down)
> +			rte_power_freq_down(lcore_id);
> +	}
>  	else if ( (unsigned)(stats[lcore_id].nb_rx_processed /
> -		stats[lcore_id].nb_iteration_looped) < MAX_PKT_BURST)
> +		stats[lcore_id].nb_iteration_looped) < MAX_PKT_BURST) {
>  		/**
>  		 * scale down a step if average packet per iteration less
>  		 * than expectation.
>  		 */
> -		rte_power_freq_down(lcore_id);
> +		if (rte_power_freq_down)
> +			rte_power_freq_down(lcore_id);
> +	}
> 
>  	/**
>  	 * initialize another timer according to current frequency to ensure
> @@ -707,22 +717,20 @@ l3fwd_simple_forward(struct rte_mbuf *m, uint8_t
> portid,
> 
>  }
> 
> -#define SLEEP_GEAR1_THRESHOLD            100
> -#define SLEEP_GEAR2_THRESHOLD            1000
> +#define MINIMUM_SLEEP_TIME         1
> +#define SUSPEND_THRESHOLD          300
> 
>  static inline uint32_t
>  power_idle_heuristic(uint32_t zero_rx_packet_count)
>  {
> -	/* If zero count is less than 100, use it as the sleep time in us */
> -	if (zero_rx_packet_count < SLEEP_GEAR1_THRESHOLD)
> -		return zero_rx_packet_count;
> -	/* If zero count is less than 1000, sleep time should be 100 us */
> -	else if ((zero_rx_packet_count >= SLEEP_GEAR1_THRESHOLD) &&
> -			(zero_rx_packet_count < SLEEP_GEAR2_THRESHOLD))
> -		return SLEEP_GEAR1_THRESHOLD;
> -	/* If zero count is greater than 1000, sleep time should be 1000 us */
> -	else if (zero_rx_packet_count >= SLEEP_GEAR2_THRESHOLD)
> -		return SLEEP_GEAR2_THRESHOLD;
> +	/* If zero count is less than 100,  sleep 1us */
> +	if (zero_rx_packet_count < SUSPEND_THRESHOLD)
> +		return MINIMUM_SLEEP_TIME;
> +	/* If zero count is less than 1000, sleep 100 us which is the minimum
> latency
> +	    switching from C3/C6 to C0
> +	*/
> +	else
> +		return SUSPEND_THRESHOLD;
> 
>  	return 0;
>  }
> @@ -762,6 +770,35 @@ power_freq_scaleup_heuristic(unsigned lcore_id,
>  	return FREQ_CURRENT;
>  }
> 
> +/**
> + * force polling thread sleep until one-shot rx interrupt triggers
> + * @param port_id
> + *  Port id.
> + * @param queue_id
> + *  Rx queue id.
> + * @return
> + *  0 on success
> + */
> +static int
> +sleep_until_rx_interrupt(uint8_t port_id, uint8_t queue_id)
> +{
> +	/* Enable one-shot rx interrupt */
> +	rte_eth_dev_rx_queue_intr_enable(port_id, queue_id);
> +
> +	RTE_LOG(INFO, L3FWD_POWER,
> +		"lcore %u sleeps until interrupt on port%d,rxq%d triggers\n",
> +		rte_lcore_id(), port_id, queue_id);
> +	rte_eal_wait_rx_intr(port_id, queue_id);
> +	RTE_LOG(INFO, L3FWD_POWER,
> +		"lcore %u is waked up from rx interrupt on port%d,rxq%d\n",
> +		rte_lcore_id(), port_id, queue_id);
> +
> +	/* Disable one-shot rx interrupt */
> +	rte_eth_dev_rx_queue_intr_disable(port_id, queue_id);
> +
> +	return 0;
> +}
> +
>  /* main processing loop */
>  static int
>  main_loop(__attribute__((unused)) void *dummy)
> @@ -775,7 +812,6 @@ main_loop(__attribute__((unused)) void *dummy)
>  	struct lcore_conf *qconf;
>  	struct lcore_rx_queue *rx_queue;
>  	enum freq_scale_hint_t lcore_scaleup_hint;
> -
>  	uint32_t lcore_rx_idle_count = 0;
>  	uint32_t lcore_idle_hint = 0;
> 
> @@ -835,6 +871,8 @@ main_loop(__attribute__((unused)) void *dummy)
>  			prev_tsc_power = cur_tsc_power;
>  		}
> 
> +
> +start_rx:
>  		/*
>  		 * Read packet from RX queues
>  		 */
> @@ -848,6 +886,7 @@ main_loop(__attribute__((unused)) void *dummy)
> 
>  			nb_rx = rte_eth_rx_burst(portid, queueid, pkts_burst,
>  								MAX_PKT_BURST);
> +
>  			stats[lcore_id].nb_rx_processed += nb_rx;
>  			if (unlikely(nb_rx == 0)) {
>  				/**
> @@ -910,10 +949,13 @@ main_loop(__attribute__((unused)) void *dummy)
>  						rx_queue->freq_up_hint;
>  			}
> 
> -			if (lcore_scaleup_hint == FREQ_HIGHEST)
> -				rte_power_freq_max(lcore_id);
> -			else if (lcore_scaleup_hint == FREQ_HIGHER)
> -				rte_power_freq_up(lcore_id);
> +			if (lcore_scaleup_hint == FREQ_HIGHEST) {
> +				if (rte_power_freq_max)
> +					rte_power_freq_max(lcore_id);
> +			} else if (lcore_scaleup_hint == FREQ_HIGHER) {
> +				if (rte_power_freq_up)
> +					rte_power_freq_up(lcore_id);
> +			}
>  		} else {
>  			/**
>  			 * All Rx queues empty in recent consecutive polls,
> @@ -928,21 +970,55 @@ main_loop(__attribute__((unused)) void *dummy)
>  					lcore_idle_hint = rx_queue->idle_hint;
>  			}
> 
> -			if ( lcore_idle_hint < SLEEP_GEAR1_THRESHOLD)
> +			if (lcore_idle_hint < SUSPEND_THRESHOLD)
>  				/**
> -				 * execute "pause" instruction to avoid context
> -				 * switch for short sleep.
> - 				 */
> +				* execute "pause" instruction to avoid context
> +				* switch which generally take hundres of microsecond
> +				* for short sleep.
> +				*/
>  				rte_delay_us(lcore_idle_hint);
> -			else
> -				/* long sleep force runing thread to suspend */
> -				usleep(lcore_idle_hint);
> -
> +			else {
> +				/* suspend untill rx interrupt trigges */
> +				sleep_until_rx_interrupt(
> +					qconf->rx_queue_list[0].port_id,
> +					qconf->rx_queue_list[0].queue_id);
> +				/* start receiving packets immediately */
> +				goto start_rx;
> +			}
>  			stats[lcore_id].sleep_time += lcore_idle_hint;
>  		}
>  	}
>  }
> 
> +/**
> + * It will be called as the callback for specified port after a LSI interrupt
> + * has been fully handled. This callback needs to be implemented carefully as
> + * it will be called in the interrupt host thread which is different from the
> + * application main thread.
> + *
> + * @param port_id
> + *  Port id.
> + * @param type
> + *  event type.
> + * @param param
> + *  Pointer to(address of) the parameters.
> + *
> + * @return
> + *  void.
> + */
> +
> +/*
> +static void
> +rx_interrupt_event_callback(uint8_t port_id, enum rte_eth_event_type type,
> void *param)
> +{
> +	uint64_t rx_queues = *((uint64_t *)param);
> +
> +	port_id = port_id + 1;
> +	if(type == RTE_ETH_EVENT_INTR_RX)
> +		port_id = rx_queues;
[LCM] What's bunch of things for ?

> +}
> +*/
> +
>  static int
>  check_lcore_params(void)
>  {
> @@ -1270,7 +1346,7 @@ setup_hash(int socketid)
>  	char s[64];
> 
>  	/* create ipv4 hash */
> -	snprintf(s, sizeof(s), "ipv4_l3fwd_hash_%d", socketid);
> +	rte_snprintf(s, sizeof(s), "ipv4_l3fwd_hash_%d", socketid);
>  	ipv4_l3fwd_hash_params.name = s;
>  	ipv4_l3fwd_hash_params.socket_id = socketid;
>  	ipv4_l3fwd_lookup_struct[socketid] =
> @@ -1280,7 +1356,7 @@ setup_hash(int socketid)
>  				"socket %d\n", socketid);
> 
>  	/* create ipv6 hash */
> -	snprintf(s, sizeof(s), "ipv6_l3fwd_hash_%d", socketid);
> +	rte_snprintf(s, sizeof(s), "ipv6_l3fwd_hash_%d", socketid);
>  	ipv6_l3fwd_hash_params.name = s;
>  	ipv6_l3fwd_hash_params.socket_id = socketid;
>  	ipv6_l3fwd_lookup_struct[socketid] =
> @@ -1476,6 +1552,7 @@ main(int argc, char **argv)
>  	unsigned lcore_id;
>  	uint64_t hz;
>  	uint32_t n_tx_queue, nb_lcores;
> +	uint32_t dev_rxq_num, dev_txq_num;
>  	uint8_t portid, nb_rx_queue, queue, socketid;
> 
>  	/* catch SIGINT and restore cpufreq governor to ondemand */
> @@ -1525,10 +1602,18 @@ main(int argc, char **argv)
>  		printf("Initializing port %d ... ", portid );
>  		fflush(stdout);
> 
> +		rte_eth_dev_info_get(portid, &dev_info);
> +		dev_rxq_num = dev_info.max_rx_queues;
> +		dev_txq_num = dev_info.max_tx_queues;
> +
>  		nb_rx_queue = get_port_n_rx_queues(portid);
> +		if (nb_rx_queue > dev_rxq_num)
> +			rte_exit(EXIT_FAILURE, "Cannot configure not existed rxq: "
> +					"port=%d\n", portid);
> +
>  		n_tx_queue = nb_lcores;
> -		if (n_tx_queue > MAX_TX_QUEUE_PER_PORT)
> -			n_tx_queue = MAX_TX_QUEUE_PER_PORT;
> +		if (n_tx_queue > dev_txq_num)
> +			n_tx_queue = dev_txq_num;
>  		printf("Creating queues: nb_rxq=%d nb_txq=%u... ",
>  			nb_rx_queue, (unsigned)n_tx_queue );
>  		ret = rte_eth_dev_configure(portid, nb_rx_queue,
> @@ -1552,6 +1637,9 @@ main(int argc, char **argv)
>  			if (rte_lcore_is_enabled(lcore_id) == 0)
>  				continue;
> 
> +			if (queueid >= dev_txq_num)
> +				continue;
> +
>  			if (numa_on)
>  				socketid = \
>  				(uint8_t)rte_lcore_to_socket_id(lcore_id);
> @@ -1586,8 +1674,9 @@ main(int argc, char **argv)
>  		/* init power management library */
>  		ret = rte_power_init(lcore_id);
>  		if (ret)
> -			rte_exit(EXIT_FAILURE, "Power management library "
> -				"initialization failed on core%u\n", lcore_id);
> +			rte_log(RTE_LOG_ERR, RTE_LOGTYPE_POWER,
> +				"Power management library initialization "
> +				"failed on core%u", lcore_id);
> 
>  		/* init timer structures for each enabled lcore */
>  		rte_timer_init(&power_timers[lcore_id]);
> @@ -1635,7 +1724,6 @@ main(int argc, char **argv)
>  		if (ret < 0)
>  			rte_exit(EXIT_FAILURE, "rte_eth_dev_start: err=%d, "
>  						"port=%d\n", ret, portid);
> -
>  		/*
>  		 * If enabled, put device in promiscuous mode.
>  		 * This allows IO forwarding mode to forward packets
> --
> 1.8.1.4