Commit 086346a4 authored by Ben Walker's avatar Ben Walker
Browse files

event: Allow idle reactors to sleep 



The user can now specify a maximum delay, in microseconds, that
defines the maximum amount of time a reactor will sleep for
between polling for new events. By default, the time is 0
which means the reactor will never sleep.

Change-Id: I94cddb69c832524878cad97b66673daa4bd5c721
Signed-off-by: default avatarBen Walker <benjamin.walker@intel.com>
parent 4179c0ac

include/spdk/event.h

+8 −1
Original line number Diff line number Diff line
@@ -131,6 +131,13 @@ struct spdk_app_opts { 
	uint32_t		dpdk_mem_channel;

	uint32_t 		dpdk_master_core;

	int			dpdk_mem_size;



	/* The maximum latency allowed when passing an event

	 * from one core to another. A value of 0

	 * means all cores continually poll. This is

	 * specified in microseconds.

	 */

	uint64_t		max_delay_us;

};



/**
@@ -213,7 +220,7 @@ void spdk_event_call(spdk_event_t event); 
#define spdk_event_get_arg2(event)	(event)->arg2



/* TODO: This is only used by tests and should be made private */

void spdk_event_queue_run_all(uint32_t lcore);

uint32_t spdk_event_queue_run_all(uint32_t lcore);



/**

 * \brief Register a poller on the given lcore.

lib/event/app.c

+2 −1
Original line number Diff line number Diff line
@@ -223,6 +223,7 @@ spdk_app_opts_init(struct spdk_app_opts *opts) 
	opts->dpdk_master_core = SPDK_APP_DPDK_DEFAULT_MASTER_CORE;

	opts->dpdk_mem_channel = SPDK_APP_DPDK_DEFAULT_MEM_CHANNEL;

	opts->reactor_mask = NULL;

	opts->max_delay_us = 0;

}



void
@@ -322,7 +323,7 @@ spdk_app_init(struct spdk_app_opts *opts) 
	 *  reactor_mask will be NULL which will enable all cores to run

	 *  reactors.

	 */

	if (spdk_reactors_init(opts->reactor_mask)) {

	if (spdk_reactors_init(opts->reactor_mask, opts->max_delay_us)) {

		fprintf(stderr, "Invalid reactor mask.\n");

		exit(EXIT_FAILURE);

	}

lib/event/reactor.c

+53 −8
Original line number Diff line number Diff line
@@ -59,6 +59,8 @@ 


#define SPDK_MAX_SOCKET		64



#define SPDK_REACTOR_SPIN_TIME_US	1



struct spdk_poller {

	TAILQ_ENTRY(spdk_poller)	tailq;

	uint32_t			lcore;
@@ -94,6 +96,8 @@ struct spdk_reactor { 
	TAILQ_HEAD(timer_pollers_head, spdk_poller)	timer_pollers;



	struct rte_ring					*events;



	uint64_t					max_delay_us;

};



static struct spdk_reactor g_reactors[RTE_MAX_LCORE];
@@ -102,7 +106,8 @@ static int g_reactor_count = 0; 


static enum spdk_reactor_state	g_reactor_state = SPDK_REACTOR_STATE_INVALID;



static void spdk_reactor_construct(struct spdk_reactor *w, uint32_t lcore);

static void spdk_reactor_construct(struct spdk_reactor *w, uint32_t lcore,

				   uint64_t max_delay_us);



struct rte_mempool *g_spdk_event_mempool[SPDK_MAX_SOCKET];
@@ -203,13 +208,15 @@ spdk_event_queue_run(uint32_t lcore, uint32_t count) 
	}

}



void

uint32_t

spdk_event_queue_run_all(uint32_t lcore)

{

	uint32_t count;



	count = spdk_event_queue_count(lcore);

	spdk_event_queue_run(lcore, count);



	return count;

}



/**
@@ -293,12 +300,23 @@ _spdk_reactor_run(void *arg) 
{

	struct spdk_reactor	*reactor = arg;

	struct spdk_poller	*poller;

	uint32_t		event_count;

	uint64_t		last_action, now;

	uint64_t		spin_cycles, sleep_cycles;

	uint32_t		sleep_us;



	set_reactor_thread_name();

	SPDK_NOTICELOG("waiting for work item to arrive...\n");

	SPDK_NOTICELOG("Reactor started on core 0x%x\n", rte_lcore_id());



	spin_cycles = SPDK_REACTOR_SPIN_TIME_US * rte_get_timer_hz() / 1000000ULL;

	sleep_cycles = reactor->max_delay_us * rte_get_timer_hz() / 1000000ULL;

	last_action = rte_get_timer_cycles();



	while (1) {

		spdk_event_queue_run_all(rte_lcore_id());

		event_count = spdk_event_queue_run_all(rte_lcore_id());

		if (event_count > 0) {

			last_action = rte_get_timer_cycles();

		}



		rte_timer_manage();
@@ -307,11 +325,12 @@ _spdk_reactor_run(void *arg) 
			TAILQ_REMOVE(&reactor->active_pollers, poller, tailq);

			poller->fn(poller->arg);

			TAILQ_INSERT_TAIL(&reactor->active_pollers, poller, tailq);

			last_action = rte_get_timer_cycles();

		}



		poller = TAILQ_FIRST(&reactor->timer_pollers);

		if (poller) {

			uint64_t now = rte_get_timer_cycles();

			now = rte_get_timer_cycles();



			if (now >= poller->next_run_tick) {

				TAILQ_REMOVE(&reactor->timer_pollers, poller, tailq);
@@ -320,6 +339,31 @@ _spdk_reactor_run(void *arg) 
			}

		}



		/* Determine if the thread can sleep */

		if (sleep_cycles > 0) {

			now = rte_get_timer_cycles();

			if (now >= (last_action + spin_cycles)) {

				sleep_us = reactor->max_delay_us;



				poller = TAILQ_FIRST(&reactor->timer_pollers);

				if (poller) {

					/* There are timers registered, so don't sleep beyond

					 * when the next timer should fire */

					if (poller->next_run_tick < (now + sleep_cycles)) {

						if (poller->next_run_tick <= now) {

							sleep_us = 0;

						} else {

							sleep_us = ((poller->next_run_tick - now) * 1000000ULL) / rte_get_timer_hz();

						}

					}

				}



				if (sleep_us > 0) {

					usleep(sleep_us);

				}

			}

		}



		if (g_reactor_state != SPDK_REACTOR_STATE_RUNNING) {

			break;

		}
@@ -329,11 +373,12 @@ _spdk_reactor_run(void *arg) 
}



static void

spdk_reactor_construct(struct spdk_reactor *reactor, uint32_t lcore)

spdk_reactor_construct(struct spdk_reactor *reactor, uint32_t lcore, uint64_t max_delay_us)

{

	char	ring_name[64];



	reactor->lcore = lcore;

	reactor->max_delay_us = max_delay_us;



	TAILQ_INIT(&reactor->active_pollers);

	TAILQ_INIT(&reactor->timer_pollers);
@@ -492,7 +537,7 @@ void spdk_reactors_stop(void) 
}



int

spdk_reactors_init(const char *mask)

spdk_reactors_init(const char *mask, unsigned int max_delay_us)

{

	uint32_t i;

	int rc;
@@ -511,7 +556,7 @@ spdk_reactors_init(const char *mask) 
	RTE_LCORE_FOREACH(i) {

		if (((1ULL << i) & spdk_app_get_core_mask())) {

			reactor = spdk_reactor_get(i);

			spdk_reactor_construct(reactor, i);

			spdk_reactor_construct(reactor, i, max_delay_us);

			g_reactor_count++;

		}

	}

lib/event/reactor.h

+1 −1
Original line number Diff line number Diff line
@@ -34,7 +34,7 @@ 
#ifndef SPDK_REACTOR_H_

#define SPDK_REACTOR_H_



int spdk_reactors_init(const char *mask);

int spdk_reactors_init(const char *mask, unsigned int max_delay_us);

int spdk_reactors_fini(void);



void spdk_reactors_start(void);

test/lib/event/reactor/reactor.c

+1 −1
Original line number Diff line number Diff line
@@ -98,6 +98,7 @@ main(int argc, char **argv) 


	spdk_app_opts_init(&opts);

	opts.name = "reactor";

	opts.max_delay_us = 1000;



	g_time_in_sec = 0;
@@ -121,7 +122,6 @@ main(int argc, char **argv) 


	opts.shutdown_cb = test_cleanup;



	spdk_app_opts_init(&opts);

	spdk_app_init(&opts);



	spdk_app_start(test_start, NULL, NULL);