event: add timer-based pollers

Allow pollers to be scheduled to be run periodically every N
microseconds instead of every iteration of the reactor loop.

Change-Id: Iaea3e98965d81044e6dc5ce5f406bcb7a455289e
Signed-off-by: Daniel Verkamp <daniel.verkamp@intel.com>

include/spdk/event.h

@@ -105,6 +105,8 @@ typedef void (*spdk_poller_fn)(void *arg);
 struct spdk_poller {
 	TAILQ_ENTRY(spdk_poller)	tailq;
 	uint32_t			lcore;
+	uint64_t			period_ticks;
+	uint64_t			next_run_tick;
 	spdk_poller_fn			fn;
 	void				*arg;
 };
@@ -220,7 +222,8 @@ void spdk_event_queue_run_all(uint32_t lcore);
  */
 void spdk_poller_register(struct spdk_poller *poller,
 			  uint32_t lcore,
-			  struct spdk_event *complete);
+			  struct spdk_event *complete,
+			  uint64_t period_microseconds);
 
 /**
  * \brief Unregister a poller on the given lcore.

lib/bdev/bdev.c

@@ -448,7 +448,7 @@ spdk_bdev_io_submit(struct spdk_bdev_io *bdev_io)
 		if (lcore == 0) {
 			lcore = rte_lcore_id();
 		}
-		spdk_poller_register(&bdev->poller, lcore, NULL);
+		spdk_poller_register(&bdev->poller, lcore, NULL, 0);
 	}
 
 	if (bdev_io->status == SPDK_BDEV_IO_STATUS_PENDING) {

lib/event/reactor.c

@@ -47,6 +47,7 @@
 #endif
 
 #include <rte_config.h>
+#include <rte_cycles.h>
 #include <rte_debug.h>
 #include <rte_mempool.h>
 #include <rte_ring.h>
@@ -68,7 +69,7 @@ enum spdk_reactor_state {
 
 struct spdk_reactor {
 	/* Logical core number for this reactor. */
-	uint32_t			lcore;
+	uint32_t					lcore;
 
 	/*
 	 * Contains pollers actively running on this reactor.  Pollers
@@ -76,9 +77,14 @@ struct spdk_reactor {
 	 *  of the ring, executes it, then puts it back at the tail of
 	 *  the ring.
 	 */
-	TAILQ_HEAD(, spdk_poller)	active_pollers;
+	TAILQ_HEAD(, spdk_poller)			active_pollers;
 
-	struct rte_ring			*events;
+	/**
+	 * Contains pollers running on this reactor with a periodic timer.
+	 */
+	TAILQ_HEAD(timer_pollers_head, spdk_poller)	timer_pollers;
+
+	struct rte_ring					*events;
 };
 
 static struct spdk_reactor g_reactors[RTE_MAX_LCORE];
@@ -220,6 +226,30 @@ static void set_reactor_thread_name(void)
 #endif
 }
 
+static void
+spdk_poller_insert_timer(struct spdk_reactor *reactor, struct spdk_poller *poller, uint64_t now)
+{
+	struct spdk_poller *iter;
+	uint64_t next_run_tick;
+
+	next_run_tick = now + poller->period_ticks;
+	poller->next_run_tick = next_run_tick;
+
+	/*
+	 * Insert poller in the reactor's timer_pollers list in sorted order by next scheduled
+	 * run time.
+	 */
+	TAILQ_FOREACH_REVERSE(iter, &reactor->timer_pollers, timer_pollers_head, tailq) {
+		if (iter->next_run_tick <= next_run_tick) {
+			TAILQ_INSERT_AFTER(&reactor->timer_pollers, iter, poller, tailq);
+			return;
+		}
+	}
+
+	/* No earlier pollers were found, so this poller must be the new head */
+	TAILQ_INSERT_HEAD(&reactor->timer_pollers, poller, tailq);
+}
+
 /**
 
 \brief This is the main function of the reactor thread.
@@ -270,6 +300,17 @@ _spdk_reactor_run(void *arg)
 			TAILQ_INSERT_TAIL(&reactor->active_pollers, poller, tailq);
 		}
 
+		poller = TAILQ_FIRST(&reactor->timer_pollers);
+		if (poller) {
+			uint64_t now = rte_get_timer_cycles();
+
+			if (now >= poller->next_run_tick) {
+				TAILQ_REMOVE(&reactor->timer_pollers, poller, tailq);
+				poller->fn(poller->arg);
+				spdk_poller_insert_timer(reactor, poller, now);
+			}
+		}
+
 		if (g_reactor_state != SPDK_REACTOR_STATE_RUNNING) {
 			break;
 		}
@@ -286,6 +327,7 @@ spdk_reactor_construct(struct spdk_reactor *reactor, uint32_t lcore)
 	reactor->lcore = lcore;
 
 	TAILQ_INIT(&reactor->active_pollers);
+	TAILQ_INIT(&reactor->timer_pollers);
 
 	snprintf(ring_name, sizeof(ring_name) - 1, "spdk_event_queue_%u", lcore);
 	reactor->events =
@@ -523,16 +565,20 @@ _spdk_event_add_poller(spdk_event_t event)
 
 	poller->lcore = reactor->lcore;
 
-	TAILQ_INSERT_TAIL(&reactor->active_pollers, poller, tailq);
+	if (poller->period_ticks) {
+		spdk_poller_insert_timer(reactor, poller, rte_get_timer_cycles());
+	} else {
+		TAILQ_INSERT_TAIL(&reactor->active_pollers, poller, tailq);
+	}
 
 	if (next) {
 		spdk_event_call(next);
 	}
 }
 
-void
+static void
-spdk_poller_register(struct spdk_poller *poller,
+_spdk_poller_register(struct spdk_poller *poller, uint32_t lcore,
-		     uint32_t lcore, spdk_event_t complete)
+		      struct spdk_event *complete)
 {
 	struct spdk_reactor *reactor;
 	struct spdk_event *event;
@@ -542,6 +588,19 @@ spdk_poller_register(struct spdk_poller *poller,
 	spdk_event_call(event);
 }
 
+void
+spdk_poller_register(struct spdk_poller *poller,
+		     uint32_t lcore, struct spdk_event *complete, uint64_t period_microseconds)
+{
+	if (period_microseconds) {
+		poller->period_ticks = (rte_get_timer_hz() * period_microseconds) / 1000000ULL;
+	} else {
+		poller->period_ticks = 0;
+	}
+
+	_spdk_poller_register(poller, lcore, complete);
+}
+
 static void
 _spdk_event_remove_poller(spdk_event_t event)
 {
@@ -549,7 +608,11 @@ _spdk_event_remove_poller(spdk_event_t event)
 	struct spdk_poller *poller = spdk_event_get_arg2(event);
 	struct spdk_event *next = spdk_event_get_next(event);
 
-	TAILQ_REMOVE(&reactor->active_pollers, poller, tailq);
+	if (poller->period_ticks) {
+		TAILQ_REMOVE(&reactor->timer_pollers, poller, tailq);
+	} else {
+		TAILQ_REMOVE(&reactor->active_pollers, poller, tailq);
+	}
 
 	if (next) {
 		spdk_event_call(next);
@@ -579,7 +642,7 @@ _spdk_poller_migrate(spdk_event_t event)
 	 * because we already set this event up so that it is called
 	 * on the new_lcore.
 	 */
-	spdk_poller_register(poller, rte_lcore_id(), next);
+	_spdk_poller_register(poller, rte_lcore_id(), next);
 }
 
 void

lib/nvmf/subsystem.c

@@ -115,7 +115,7 @@ nvmf_create_subsystem(int num, const char *name,
 
 	subsystem->poller.fn = spdk_nvmf_subsystem_poller;
 	subsystem->poller.arg = subsystem;
-	spdk_poller_register(&subsystem->poller, lcore, NULL);
+	spdk_poller_register(&subsystem->poller, lcore, NULL, 0);
 
 	TAILQ_INSERT_HEAD(&g_subsystems, subsystem, entries);
 

test/lib/event/Makefile

@@ -34,7 +34,7 @@
 SPDK_ROOT_DIR := $(abspath $(CURDIR)/../../..)
 include $(SPDK_ROOT_DIR)/mk/spdk.common.mk
 
-DIRS-y = event subsystem
+DIRS-y = event reactor subsystem
 
 .PHONY: all clean $(DIRS-y)
 

test/lib/event/event.sh

@@ -6,5 +6,6 @@ source $rootdir/scripts/autotest_common.sh
 
 timing_enter event
 $testdir/event/event -m 0xF -t 5
+$testdir/reactor/reactor -t 1
 $testdir/subsystem/subsystem_ut
 timing_exit event

test/lib/event/reactor/.gitignore

@@ -0,0 +1 @@
+reactor

test/lib/event/reactor/Makefile

@@ -0,0 +1,57 @@
+#
+#  BSD LICENSE
+#
+#  Copyright (c) Intel Corporation.
+#  All rights reserved.
+#
+#  Redistribution and use in source and binary forms, with or without
+#  modification, are permitted provided that the following conditions
+#  are met:
+#
+#    * Redistributions of source code must retain the above copyright
+#      notice, this list of conditions and the following disclaimer.
+#    * Redistributions in binary form must reproduce the above copyright
+#      notice, this list of conditions and the following disclaimer in
+#      the documentation and/or other materials provided with the
+#      distribution.
+#    * Neither the name of Intel Corporation nor the names of its
+#      contributors may be used to endorse or promote products derived
+#      from this software without specific prior written permission.
+#
+#  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+#  "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+#  LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+#  A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+#  OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+#  SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+#  LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+#  DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+#  THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+#  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+#  OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+#
+
+SPDK_ROOT_DIR := $(abspath $(CURDIR)/../../../..)
+include $(SPDK_ROOT_DIR)/mk/spdk.common.mk
+
+CFLAGS += $(DPDK_INC)
+APP = reactor
+C_SRCS := reactor.c
+
+SPDK_LIBS += $(SPDK_ROOT_DIR)/lib/event/libspdk_event.a \
+	     $(SPDK_ROOT_DIR)/lib/trace/libspdk_trace.a \
+	     $(SPDK_ROOT_DIR)/lib/conf/libspdk_conf.a \
+	     $(SPDK_ROOT_DIR)/lib/util/libspdk_util.a \
+	     $(SPDK_ROOT_DIR)/lib/log/libspdk_log.a \
+
+LIBS += $(SPDK_LIBS) $(DPDK_LIB)
+
+all : $(APP)
+
+$(APP) : $(OBJS) $(SPDK_LIBS)
+	$(LINK_C)
+
+clean :
+	$(CLEAN_C) $(APP)
+
+include $(SPDK_ROOT_DIR)/mk/spdk.deps.mk

test/lib/event/reactor/reactor.c

@@ -0,0 +1,143 @@
+/*-
+ *   BSD LICENSE
+ *
+ *   Copyright (c) Intel Corporation.
+ *   All rights reserved.
+ *
+ *   Redistribution and use in source and binary forms, with or without
+ *   modification, are permitted provided that the following conditions
+ *   are met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ *       notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above copyright
+ *       notice, this list of conditions and the following disclaimer in
+ *       the documentation and/or other materials provided with the
+ *       distribution.
+ *     * Neither the name of Intel Corporation nor the names of its
+ *       contributors may be used to endorse or promote products derived
+ *       from this software without specific prior written permission.
+ *
+ *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <inttypes.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#include "spdk/event.h"
+
+static int g_time_in_sec;
+static struct spdk_poller test_end_poller;
+static struct spdk_poller poller_100ms;
+static struct spdk_poller poller_250ms;
+static struct spdk_poller poller_500ms;
+
+static void
+test_end(void *arg)
+{
+	printf("test_end\n");
+	spdk_app_stop(0);
+}
+
+static void
+tick(void *arg)
+{
+	uintptr_t period = (uintptr_t)arg;
+
+	printf("tick %" PRIu64 "\n", (uint64_t)period);
+}
+
+static void
+test_start(spdk_event_t evt)
+{
+	printf("test_start\n");
+
+	/* Register a poller that will stop the test after the time has elapsed. */
+	test_end_poller.fn = test_end;
+	spdk_poller_register(&test_end_poller, 0, NULL, g_time_in_sec * 1000000ULL);
+
+	poller_100ms.fn = tick;
+	poller_100ms.arg = (void *)100;
+	spdk_poller_register(&poller_100ms, 0, NULL, 100000);
+
+	poller_250ms.fn = tick;
+	poller_250ms.arg = (void *)250;
+	spdk_poller_register(&poller_250ms, 0, NULL, 250000);
+
+	poller_500ms.fn = tick;
+	poller_500ms.arg = (void *)500;
+	spdk_poller_register(&poller_500ms, 0, NULL, 500000);
+}
+
+static void
+test_cleanup(void)
+{
+	printf("test_cleanup\n");
+
+	spdk_poller_unregister(&test_end_poller, NULL);
+	spdk_poller_unregister(&poller_100ms, NULL);
+	spdk_poller_unregister(&poller_250ms, NULL);
+	spdk_poller_unregister(&poller_500ms, NULL);
+}
+
+static void
+usage(const char *program_name)
+{
+	printf("%s options\n", program_name);
+	printf("\t[-t time in seconds]\n");
+}
+
+int
+main(int argc, char **argv)
+{
+	struct spdk_app_opts opts;
+	int op;
+
+	spdk_app_opts_init(&opts);
+	opts.name = "reactor";
+
+	g_time_in_sec = 0;
+
+	while ((op = getopt(argc, argv, "t:")) != -1) {
+		switch (op) {
+		case 't':
+			g_time_in_sec = atoi(optarg);
+			break;
+		default:
+			usage(argv[0]);
+			exit(1);
+		}
+	}
+
+	if (!g_time_in_sec) {
+		usage(argv[0]);
+		exit(1);
+	}
+
+	optind = 1;
+
+	opts.shutdown_cb = test_cleanup;
+
+	spdk_app_opts_init(&opts);
+	spdk_app_init(&opts);
+
+	spdk_app_start(test_start, NULL, NULL);
+
+	test_cleanup();
+
+	spdk_app_fini();
+
+	return 0;
+}

test/lib/nvmf/subsystem/subsystem_ut.c

@@ -43,7 +43,8 @@
 SPDK_LOG_REGISTER_TRACE_FLAG("nvmf", SPDK_TRACE_NVMF)
 
 void
-spdk_poller_register(struct spdk_poller *poller, uint32_t lcore, struct spdk_event *complete)
+spdk_poller_register(struct spdk_poller *poller, uint32_t lcore, struct spdk_event *complete,
+		     uint64_t period_microseconds)
 {
 }