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Diffstat (limited to 'src/spdk/lib/event/reactor.c')
-rw-r--r-- | src/spdk/lib/event/reactor.c | 664 |
1 files changed, 664 insertions, 0 deletions
diff --git a/src/spdk/lib/event/reactor.c b/src/spdk/lib/event/reactor.c new file mode 100644 index 000000000..cda4a32b1 --- /dev/null +++ b/src/spdk/lib/event/reactor.c @@ -0,0 +1,664 @@ +/*- + * 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 "spdk/stdinc.h" +#include "spdk/likely.h" + +#include "spdk_internal/event.h" +#include "spdk_internal/log.h" +#include "spdk_internal/thread.h" + +#include "spdk/log.h" +#include "spdk/thread.h" +#include "spdk/env.h" +#include "spdk/util.h" + +#ifdef __linux__ +#include <sys/prctl.h> +#endif + +#ifdef __FreeBSD__ +#include <pthread_np.h> +#endif + +#define SPDK_EVENT_BATCH_SIZE 8 + +static struct spdk_reactor *g_reactors; +static struct spdk_cpuset g_reactor_core_mask; +static enum spdk_reactor_state g_reactor_state = SPDK_REACTOR_STATE_UNINITIALIZED; + +static bool g_framework_context_switch_monitor_enabled = true; + +static struct spdk_mempool *g_spdk_event_mempool = NULL; + +static void +reactor_construct(struct spdk_reactor *reactor, uint32_t lcore) +{ + reactor->lcore = lcore; + reactor->flags.is_valid = true; + + TAILQ_INIT(&reactor->threads); + reactor->thread_count = 0; + + reactor->events = spdk_ring_create(SPDK_RING_TYPE_MP_SC, 65536, SPDK_ENV_SOCKET_ID_ANY); + assert(reactor->events != NULL); +} + +struct spdk_reactor * +spdk_reactor_get(uint32_t lcore) +{ + struct spdk_reactor *reactor; + + if (g_reactors == NULL) { + SPDK_WARNLOG("Called spdk_reactor_get() while the g_reactors array was NULL!\n"); + return NULL; + } + + reactor = &g_reactors[lcore]; + + if (reactor->flags.is_valid == false) { + return NULL; + } + + return reactor; +} + +static int reactor_thread_op(struct spdk_thread *thread, enum spdk_thread_op op); +static bool reactor_thread_op_supported(enum spdk_thread_op op); + +int +spdk_reactors_init(void) +{ + int rc; + uint32_t i, last_core; + char mempool_name[32]; + + snprintf(mempool_name, sizeof(mempool_name), "evtpool_%d", getpid()); + g_spdk_event_mempool = spdk_mempool_create(mempool_name, + 262144 - 1, /* Power of 2 minus 1 is optimal for memory consumption */ + sizeof(struct spdk_event), + SPDK_MEMPOOL_DEFAULT_CACHE_SIZE, + SPDK_ENV_SOCKET_ID_ANY); + + if (g_spdk_event_mempool == NULL) { + SPDK_ERRLOG("spdk_event_mempool creation failed\n"); + return -1; + } + + /* struct spdk_reactor must be aligned on 64 byte boundary */ + last_core = spdk_env_get_last_core(); + rc = posix_memalign((void **)&g_reactors, 64, + (last_core + 1) * sizeof(struct spdk_reactor)); + if (rc != 0) { + SPDK_ERRLOG("Could not allocate array size=%u for g_reactors\n", + last_core + 1); + spdk_mempool_free(g_spdk_event_mempool); + return -1; + } + + memset(g_reactors, 0, (last_core + 1) * sizeof(struct spdk_reactor)); + + spdk_thread_lib_init_ext(reactor_thread_op, reactor_thread_op_supported, + sizeof(struct spdk_lw_thread)); + + SPDK_ENV_FOREACH_CORE(i) { + reactor_construct(&g_reactors[i], i); + } + + g_reactor_state = SPDK_REACTOR_STATE_INITIALIZED; + + return 0; +} + +void +spdk_reactors_fini(void) +{ + uint32_t i; + struct spdk_reactor *reactor; + + if (g_reactor_state == SPDK_REACTOR_STATE_UNINITIALIZED) { + return; + } + + spdk_thread_lib_fini(); + + SPDK_ENV_FOREACH_CORE(i) { + reactor = spdk_reactor_get(i); + assert(reactor != NULL); + assert(reactor->thread_count == 0); + if (reactor->events != NULL) { + spdk_ring_free(reactor->events); + } + } + + spdk_mempool_free(g_spdk_event_mempool); + + free(g_reactors); + g_reactors = NULL; +} + +struct spdk_event * +spdk_event_allocate(uint32_t lcore, spdk_event_fn fn, void *arg1, void *arg2) +{ + struct spdk_event *event = NULL; + struct spdk_reactor *reactor = spdk_reactor_get(lcore); + + if (!reactor) { + assert(false); + return NULL; + } + + event = spdk_mempool_get(g_spdk_event_mempool); + if (event == NULL) { + assert(false); + return NULL; + } + + event->lcore = lcore; + event->fn = fn; + event->arg1 = arg1; + event->arg2 = arg2; + + return event; +} + +void +spdk_event_call(struct spdk_event *event) +{ + int rc; + struct spdk_reactor *reactor; + + reactor = spdk_reactor_get(event->lcore); + + assert(reactor != NULL); + assert(reactor->events != NULL); + + rc = spdk_ring_enqueue(reactor->events, (void **)&event, 1, NULL); + if (rc != 1) { + assert(false); + } +} + +static inline uint32_t +event_queue_run_batch(struct spdk_reactor *reactor) +{ + unsigned count, i; + void *events[SPDK_EVENT_BATCH_SIZE]; + struct spdk_thread *thread; + struct spdk_lw_thread *lw_thread; + +#ifdef DEBUG + /* + * spdk_ring_dequeue() fills events and returns how many entries it wrote, + * so we will never actually read uninitialized data from events, but just to be sure + * (and to silence a static analyzer false positive), initialize the array to NULL pointers. + */ + memset(events, 0, sizeof(events)); +#endif + + count = spdk_ring_dequeue(reactor->events, events, SPDK_EVENT_BATCH_SIZE); + if (count == 0) { + return 0; + } + + /* Execute the events. There are still some remaining events + * that must occur on an SPDK thread. To accomodate those, try to + * run them on the first thread in the list, if it exists. */ + lw_thread = TAILQ_FIRST(&reactor->threads); + if (lw_thread) { + thread = spdk_thread_get_from_ctx(lw_thread); + } else { + thread = NULL; + } + + spdk_set_thread(thread); + + for (i = 0; i < count; i++) { + struct spdk_event *event = events[i]; + + assert(event != NULL); + event->fn(event->arg1, event->arg2); + } + + spdk_set_thread(NULL); + + spdk_mempool_put_bulk(g_spdk_event_mempool, events, count); + + return count; +} + +/* 1s */ +#define CONTEXT_SWITCH_MONITOR_PERIOD 1000000 + +static int +get_rusage(struct spdk_reactor *reactor) +{ + struct rusage rusage; + + if (getrusage(RUSAGE_THREAD, &rusage) != 0) { + return -1; + } + + if (rusage.ru_nvcsw != reactor->rusage.ru_nvcsw || rusage.ru_nivcsw != reactor->rusage.ru_nivcsw) { + SPDK_INFOLOG(SPDK_LOG_REACTOR, + "Reactor %d: %ld voluntary context switches and %ld involuntary context switches in the last second.\n", + reactor->lcore, rusage.ru_nvcsw - reactor->rusage.ru_nvcsw, + rusage.ru_nivcsw - reactor->rusage.ru_nivcsw); + } + reactor->rusage = rusage; + + return -1; +} + +void +spdk_framework_enable_context_switch_monitor(bool enable) +{ + /* This global is being read by multiple threads, so this isn't + * strictly thread safe. However, we're toggling between true and + * false here, and if a thread sees the value update later than it + * should, it's no big deal. */ + g_framework_context_switch_monitor_enabled = enable; +} + +bool +spdk_framework_context_switch_monitor_enabled(void) +{ + return g_framework_context_switch_monitor_enabled; +} + +static void +_set_thread_name(const char *thread_name) +{ +#if defined(__linux__) + prctl(PR_SET_NAME, thread_name, 0, 0, 0); +#elif defined(__FreeBSD__) + pthread_set_name_np(pthread_self(), thread_name); +#else +#error missing platform support for thread name +#endif +} + +static int _reactor_schedule_thread(struct spdk_thread *thread); +static uint64_t g_rusage_period; + +static void +_reactor_run(struct spdk_reactor *reactor) +{ + struct spdk_thread *thread; + struct spdk_lw_thread *lw_thread, *tmp; + uint64_t now; + int rc; + + event_queue_run_batch(reactor); + + TAILQ_FOREACH_SAFE(lw_thread, &reactor->threads, link, tmp) { + thread = spdk_thread_get_from_ctx(lw_thread); + rc = spdk_thread_poll(thread, 0, reactor->tsc_last); + + now = spdk_thread_get_last_tsc(thread); + if (rc == 0) { + reactor->idle_tsc += now - reactor->tsc_last; + } else if (rc > 0) { + reactor->busy_tsc += now - reactor->tsc_last; + } + reactor->tsc_last = now; + + if (spdk_unlikely(lw_thread->resched)) { + lw_thread->resched = false; + TAILQ_REMOVE(&reactor->threads, lw_thread, link); + assert(reactor->thread_count > 0); + reactor->thread_count--; + _reactor_schedule_thread(thread); + continue; + } + + if (spdk_unlikely(spdk_thread_is_exited(thread) && + spdk_thread_is_idle(thread))) { + TAILQ_REMOVE(&reactor->threads, lw_thread, link); + assert(reactor->thread_count > 0); + reactor->thread_count--; + spdk_thread_destroy(thread); + continue; + } + } + + if (g_framework_context_switch_monitor_enabled) { + if ((reactor->last_rusage + g_rusage_period) < reactor->tsc_last) { + get_rusage(reactor); + reactor->last_rusage = reactor->tsc_last; + } + } +} + +static int +reactor_run(void *arg) +{ + struct spdk_reactor *reactor = arg; + struct spdk_thread *thread; + struct spdk_lw_thread *lw_thread, *tmp; + char thread_name[32]; + + SPDK_NOTICELOG("Reactor started on core %u\n", reactor->lcore); + + /* Rename the POSIX thread because the reactor is tied to the POSIX + * thread in the SPDK event library. + */ + snprintf(thread_name, sizeof(thread_name), "reactor_%u", reactor->lcore); + _set_thread_name(thread_name); + + reactor->tsc_last = spdk_get_ticks(); + + while (1) { + _reactor_run(reactor); + + if (g_reactor_state != SPDK_REACTOR_STATE_RUNNING) { + break; + } + } + + TAILQ_FOREACH(lw_thread, &reactor->threads, link) { + thread = spdk_thread_get_from_ctx(lw_thread); + spdk_set_thread(thread); + spdk_thread_exit(thread); + } + + while (!TAILQ_EMPTY(&reactor->threads)) { + TAILQ_FOREACH_SAFE(lw_thread, &reactor->threads, link, tmp) { + thread = spdk_thread_get_from_ctx(lw_thread); + spdk_set_thread(thread); + if (spdk_thread_is_exited(thread)) { + TAILQ_REMOVE(&reactor->threads, lw_thread, link); + assert(reactor->thread_count > 0); + reactor->thread_count--; + spdk_thread_destroy(thread); + } else { + spdk_thread_poll(thread, 0, 0); + } + } + } + + return 0; +} + +int +spdk_app_parse_core_mask(const char *mask, struct spdk_cpuset *cpumask) +{ + int ret; + struct spdk_cpuset *validmask; + + ret = spdk_cpuset_parse(cpumask, mask); + if (ret < 0) { + return ret; + } + + validmask = spdk_app_get_core_mask(); + spdk_cpuset_and(cpumask, validmask); + + return 0; +} + +struct spdk_cpuset * +spdk_app_get_core_mask(void) +{ + return &g_reactor_core_mask; +} + +void +spdk_reactors_start(void) +{ + struct spdk_reactor *reactor; + struct spdk_cpuset tmp_cpumask = {}; + uint32_t i, current_core; + int rc; + char thread_name[32]; + + g_rusage_period = (CONTEXT_SWITCH_MONITOR_PERIOD * spdk_get_ticks_hz()) / SPDK_SEC_TO_USEC; + g_reactor_state = SPDK_REACTOR_STATE_RUNNING; + + current_core = spdk_env_get_current_core(); + SPDK_ENV_FOREACH_CORE(i) { + if (i != current_core) { + reactor = spdk_reactor_get(i); + if (reactor == NULL) { + continue; + } + + rc = spdk_env_thread_launch_pinned(reactor->lcore, reactor_run, reactor); + if (rc < 0) { + SPDK_ERRLOG("Unable to start reactor thread on core %u\n", reactor->lcore); + assert(false); + return; + } + + /* For now, for each reactor spawn one thread. */ + snprintf(thread_name, sizeof(thread_name), "reactor_%u", reactor->lcore); + + spdk_cpuset_zero(&tmp_cpumask); + spdk_cpuset_set_cpu(&tmp_cpumask, i, true); + + spdk_thread_create(thread_name, &tmp_cpumask); + } + spdk_cpuset_set_cpu(&g_reactor_core_mask, i, true); + } + + /* Start the master reactor */ + reactor = spdk_reactor_get(current_core); + assert(reactor != NULL); + reactor_run(reactor); + + spdk_env_thread_wait_all(); + + g_reactor_state = SPDK_REACTOR_STATE_SHUTDOWN; +} + +void +spdk_reactors_stop(void *arg1) +{ + g_reactor_state = SPDK_REACTOR_STATE_EXITING; +} + +static pthread_mutex_t g_scheduler_mtx = PTHREAD_MUTEX_INITIALIZER; +static uint32_t g_next_core = UINT32_MAX; + +static void +_schedule_thread(void *arg1, void *arg2) +{ + struct spdk_lw_thread *lw_thread = arg1; + struct spdk_thread *thread; + struct spdk_cpuset *cpumask; + struct spdk_reactor *reactor; + uint32_t current_core; + + current_core = spdk_env_get_current_core(); + + thread = spdk_thread_get_from_ctx(lw_thread); + cpumask = spdk_thread_get_cpumask(thread); + if (!spdk_cpuset_get_cpu(cpumask, current_core)) { + SPDK_ERRLOG("Thread was scheduled to the wrong core %d\n", current_core); + assert(false); + } + + reactor = spdk_reactor_get(current_core); + assert(reactor != NULL); + + TAILQ_INSERT_TAIL(&reactor->threads, lw_thread, link); + reactor->thread_count++; +} + +static int +_reactor_schedule_thread(struct spdk_thread *thread) +{ + uint32_t core; + struct spdk_lw_thread *lw_thread; + struct spdk_event *evt = NULL; + struct spdk_cpuset *cpumask; + uint32_t i; + + cpumask = spdk_thread_get_cpumask(thread); + + lw_thread = spdk_thread_get_ctx(thread); + assert(lw_thread != NULL); + memset(lw_thread, 0, sizeof(*lw_thread)); + + pthread_mutex_lock(&g_scheduler_mtx); + for (i = 0; i < spdk_env_get_core_count(); i++) { + if (g_next_core > spdk_env_get_last_core()) { + g_next_core = spdk_env_get_first_core(); + } + core = g_next_core; + g_next_core = spdk_env_get_next_core(g_next_core); + + if (spdk_cpuset_get_cpu(cpumask, core)) { + evt = spdk_event_allocate(core, _schedule_thread, lw_thread, NULL); + break; + } + } + pthread_mutex_unlock(&g_scheduler_mtx); + + assert(evt != NULL); + if (evt == NULL) { + SPDK_ERRLOG("Unable to schedule thread on requested core mask.\n"); + return -1; + } + + lw_thread->tsc_start = spdk_get_ticks(); + + spdk_event_call(evt); + + return 0; +} + +static void +_reactor_request_thread_reschedule(struct spdk_thread *thread) +{ + struct spdk_lw_thread *lw_thread; + + assert(thread == spdk_get_thread()); + + lw_thread = spdk_thread_get_ctx(thread); + + assert(lw_thread != NULL); + + lw_thread->resched = true; +} + +static int +reactor_thread_op(struct spdk_thread *thread, enum spdk_thread_op op) +{ + switch (op) { + case SPDK_THREAD_OP_NEW: + return _reactor_schedule_thread(thread); + case SPDK_THREAD_OP_RESCHED: + _reactor_request_thread_reschedule(thread); + return 0; + default: + return -ENOTSUP; + } +} + +static bool +reactor_thread_op_supported(enum spdk_thread_op op) +{ + switch (op) { + case SPDK_THREAD_OP_NEW: + case SPDK_THREAD_OP_RESCHED: + return true; + default: + return false; + } +} + +struct call_reactor { + uint32_t cur_core; + spdk_event_fn fn; + void *arg1; + void *arg2; + + uint32_t orig_core; + spdk_event_fn cpl; +}; + +static void +on_reactor(void *arg1, void *arg2) +{ + struct call_reactor *cr = arg1; + struct spdk_event *evt; + + cr->fn(cr->arg1, cr->arg2); + + cr->cur_core = spdk_env_get_next_core(cr->cur_core); + + if (cr->cur_core > spdk_env_get_last_core()) { + SPDK_DEBUGLOG(SPDK_LOG_REACTOR, "Completed reactor iteration\n"); + + evt = spdk_event_allocate(cr->orig_core, cr->cpl, cr->arg1, cr->arg2); + free(cr); + } else { + SPDK_DEBUGLOG(SPDK_LOG_REACTOR, "Continuing reactor iteration to %d\n", + cr->cur_core); + + evt = spdk_event_allocate(cr->cur_core, on_reactor, arg1, NULL); + } + assert(evt != NULL); + spdk_event_call(evt); +} + +void +spdk_for_each_reactor(spdk_event_fn fn, void *arg1, void *arg2, spdk_event_fn cpl) +{ + struct call_reactor *cr; + struct spdk_event *evt; + + cr = calloc(1, sizeof(*cr)); + if (!cr) { + SPDK_ERRLOG("Unable to perform reactor iteration\n"); + cpl(arg1, arg2); + return; + } + + cr->fn = fn; + cr->arg1 = arg1; + cr->arg2 = arg2; + cr->cpl = cpl; + cr->orig_core = spdk_env_get_current_core(); + cr->cur_core = spdk_env_get_first_core(); + + SPDK_DEBUGLOG(SPDK_LOG_REACTOR, "Starting reactor iteration from %d\n", cr->orig_core); + + evt = spdk_event_allocate(cr->cur_core, on_reactor, cr, NULL); + assert(evt != NULL); + + spdk_event_call(evt); +} + +SPDK_LOG_REGISTER_COMPONENT("reactor", SPDK_LOG_REACTOR) |