iscsi: factor out epoll-based idle conn management (181e568e) · Commits · Public Repositories / spdk

lib/iscsi/conn.c

+102 −52

Original line number	Diff line number	Diff line
		@@ -131,6 +131,101 @@ spdk_find_iscsi_connection_by_id(int cid)
		}
		}

		static int
		init_idle_conns(void)
		{
		RTE_VERIFY(g_epoll_fd == 0);
		g_epoll_fd = epoll_create1(0);
		if (g_epoll_fd < 0) {
		SPDK_ERRLOG("epoll_create1 failed master lcore\n");
		return -1;
		}

		return 0;
		}

		static int
		add_idle_conn(struct spdk_iscsi_conn *conn)
		{
		struct epoll_event event;
		int rc;

		event.events = EPOLLIN;
		event.data.u64 = 0LL;
		event.data.ptr = conn;

		rc = epoll_ctl(g_epoll_fd, EPOLL_CTL_ADD, conn->sock, &event);
		if (rc == 0) {
		return 0;
		} else {
		SPDK_ERRLOG("conn epoll_ctl failed\n");
		return -1;
		}
		}

		static int
		del_idle_conn(struct spdk_iscsi_conn *conn)
		{
		struct epoll_event event;
		int rc;

		/*
		* The event parameter is ignored but needs to be non-NULL to work around a bug in old
		* kernel versions.
		*/
		rc = epoll_ctl(g_epoll_fd, EPOLL_CTL_DEL, conn->sock, &event);
		if (rc == 0) {
		return 0;
		} else {
		SPDK_ERRLOG("epoll_ctl(EPOLL_CTL_DEL) failed\n");
		return -1;
		}
		}

		static void
		check_idle_conns(void)
		{
		struct epoll_event events[SPDK_MAX_POLLERS_PER_CORE];
		int i;
		int nfds;
		struct spdk_iscsi_conn *conn;

		/* if nothing idle, can exit now */
		if (STAILQ_EMPTY(&g_idle_conn_list_head)) {
		/* this epoll_wait is needed to finish socket closing process */
		epoll_wait(g_epoll_fd, events, SPDK_MAX_POLLERS_PER_CORE, 0);
		}

		/* Perform a non-blocking epoll */
		nfds = epoll_wait(g_epoll_fd, events, SPDK_MAX_POLLERS_PER_CORE, 0);
		if (nfds < 0) {
		SPDK_ERRLOG("epoll_wait failed! (ret: %d)\n", nfds);
		return;
		}

		if (nfds > SPDK_MAX_POLLERS_PER_CORE) {
		SPDK_ERRLOG("epoll_wait events exceeded limit! %d > %d\n", nfds,
		SPDK_MAX_POLLERS_PER_CORE);
		RTE_VERIFY(0);
		}

		/*
		* In the case of any event cause (EPOLLIN or EPOLLERR)
		* just make the connection active for normal process loop.
		*/
		for (i = 0; i < nfds; i++) {

		conn = (struct spdk_iscsi_conn *)events[i].data.ptr;

		/*
		* Flag the connection that an event was noticed
		* such that during the list scan process it will
		* be re-inserted into the active ring
		*/
		conn->pending_activate_event = true;
		}
		}

		int spdk_initialize_iscsi_conns(void)
		{
		size_t conns_size;
		@@ -177,10 +272,7 @@ int spdk_initialize_iscsi_conns(void)
		spdk_iscsi_set_min_conn_idle_interval(spdk_net_framework_idle_time());

		STAILQ_INIT(&g_idle_conn_list_head);
		RTE_VERIFY(g_epoll_fd == 0);
		g_epoll_fd = epoll_create1(0);
		if (g_epoll_fd < 0) {
		SPDK_ERRLOG("epoll_create1 failed master lcore\n");
		if (init_idle_conns() < 0) {
		return -1;
		}

		@@ -540,7 +632,6 @@ spdk_iscsi_conn_check_shutdown(struct rte_timer timer, void arg)
		void spdk_shutdown_iscsi_conns(void)
		{
		struct spdk_iscsi_conn conn, tmp;
		struct epoll_event event;
		int i;

		/* cleanup - move conns from list back into ring
		@@ -550,7 +641,7 @@ void spdk_shutdown_iscsi_conns(void)
		STAILQ_REMOVE(&g_idle_conn_list_head, conn, spdk_iscsi_conn, link);
		spdk_poller_register(&conn->poller, rte_get_master_lcore(), NULL, 0);
		conn->is_idle = 0;
		epoll_ctl(g_epoll_fd, EPOLL_CTL_DEL, conn->sock, &event);
		del_idle_conn(conn);
		}

		pthread_mutex_lock(&g_conns_mutex);
		@@ -1155,46 +1246,10 @@ even though the connection is considered 'idle'.
		*/
		void spdk_iscsi_conn_idle_do_work(void *arg)
		{
		struct epoll_event event;
		struct epoll_event events[SPDK_MAX_POLLERS_PER_CORE];
		uint64_t tsc;
		int i;
		int nfds;
		struct spdk_iscsi_conn conn, tconn;

		/* if nothing idle, can exit now */
		if (STAILQ_EMPTY(&g_idle_conn_list_head)) {
		/* this epoll_wait is needed to finish socket closing process */
		epoll_wait(g_epoll_fd, events, SPDK_MAX_POLLERS_PER_CORE, 0);
		}

		/* Perform a non-blocking epoll */
		nfds = epoll_wait(g_epoll_fd, events, SPDK_MAX_POLLERS_PER_CORE, 0);
		if (nfds < 0) {
		SPDK_ERRLOG("epoll_wait failed! (ret: %d)\n", nfds);
		return;
		}

		if (nfds > SPDK_MAX_POLLERS_PER_CORE) {
		SPDK_ERRLOG("epoll_wait events exceeded limit! %d > %d\n", nfds,
		SPDK_MAX_POLLERS_PER_CORE);
		RTE_VERIFY(0);
		}

		/* In the case of any event cause (EPOLLIN or EPOLLERR)
		just make the connection active for normal process loop.
		*/
		for (i = 0; i < nfds; i++) {

		conn = (struct spdk_iscsi_conn *)events[i].data.ptr;

		/* Flag the connection that an event was noticed
		such that during the list scan process it will
		be re-inserted into the active ring
		*/
		conn->pending_activate_event = true;
		}
		struct spdk_iscsi_conn *tconn;

		check_idle_conns();

		/* Now walk the idle list to process timer based actions */
		STAILQ_FOREACH(tconn, &g_idle_conn_list_head, link) {
		@@ -1218,7 +1273,7 @@ void spdk_iscsi_conn_idle_do_work(void *arg)
		tconn->last_activity_tsc = rte_get_timer_cycles();
		tconn->pending_activate_event = false;
		tconn->is_idle = 0;
		epoll_ctl(g_epoll_fd, EPOLL_CTL_DEL, tconn->sock, &event);
		del_idle_conn(tconn);
		/* migrate work item to new core */
		lcore = spdk_iscsi_conn_allocate_reactor(tconn->portal->cpumask);
		rte_atomic32_inc(&g_num_connections[lcore]);
		@@ -1234,7 +1289,6 @@ static void
		__add_idle_conn(spdk_event_t e)
		{
		struct spdk_iscsi_conn *conn = spdk_event_get_arg1(e);
		struct epoll_event event;
		int rc;

		/*
		@@ -1248,18 +1302,14 @@ __add_idle_conn(spdk_event_t e)
		return;
		}

		event.events = EPOLLIN;
		event.data.u64 = 0LL;
		event.data.ptr = conn;

		rc = epoll_ctl(g_epoll_fd, EPOLL_CTL_ADD, conn->sock, &event);
		rc = add_idle_conn(conn);
		if (rc == 0) {
		SPDK_TRACELOG(SPDK_TRACE_DEBUG, "add conn id = %d, cid = %d poller = %p to lcore = %d idle\n",
		conn->id, conn->cid, &conn->poller, conn->poller.lcore);
		conn->is_idle = 1;
		STAILQ_INSERT_TAIL(&g_idle_conn_list_head, conn, link);
		} else {
		SPDK_ERRLOG("conn epoll_ctl failed\n");
		SPDK_ERRLOG("add_idle_conn() failed\n");
		}
		}