From: Anatoly Burakov Date: Tue, 26 Jun 2018 10:53:17 +0000 (+0100) Subject: ipc: remove thread for async requests X-Git-Url: http://git.droids-corp.org/?a=commitdiff_plain;h=daf9bfca717e;p=dpdk.git ipc: remove thread for async requests Previously, we were using two IPC threads - one to handle messages and synchronous requests, and another to handle asynchronous requests. To handle replies for an async request, rte_mp_handle woke up the rte_mp_handle_async thread to process through pthread_cond variable. Change it to handle asynchronous messages within the main IPC thread. To handle timeout events, for each async request which is sent, we set an alarm for it. If its reply is received before timeout, we will cancel the alarm when we handle the reply; otherwise, alarm will invoke the async_reply_handle() as the alarm callback. Signed-off-by: Jianfeng Tan Signed-off-by: Anatoly Burakov Suggested-by: Thomas Monjalon --- diff --git a/lib/librte_eal/common/eal_common_proc.c b/lib/librte_eal/common/eal_common_proc.c index f010ef59e5..0974e329bc 100644 --- a/lib/librte_eal/common/eal_common_proc.c +++ b/lib/librte_eal/common/eal_common_proc.c @@ -20,6 +20,7 @@ #include #include +#include #include #include #include @@ -94,11 +95,9 @@ TAILQ_HEAD(pending_request_list, pending_request); static struct { struct pending_request_list requests; pthread_mutex_t lock; - pthread_cond_t async_cond; } pending_requests = { .requests = TAILQ_HEAD_INITIALIZER(pending_requests.requests), .lock = PTHREAD_MUTEX_INITIALIZER, - .async_cond = PTHREAD_COND_INITIALIZER /**< used in async requests only */ }; @@ -106,6 +105,16 @@ static struct { static int mp_send(struct rte_mp_msg *msg, const char *peer, int type); +/* for use with alarm callback */ +static void +async_reply_handle(void *arg); + +/* for use with process_msg */ +static struct pending_request * +async_reply_handle_thread_unsafe(void *arg); + +static void +trigger_async_action(struct pending_request *req); static struct pending_request * find_pending_request(const char *dst, const char *act_name) @@ -290,6 +299,8 @@ process_msg(struct mp_msg_internal *m, struct sockaddr_un *s) RTE_LOG(DEBUG, EAL, "msg: %s\n", msg->name); if (m->type == MP_REP || m->type == MP_IGN) { + struct pending_request *req = NULL; + pthread_mutex_lock(&pending_requests.lock); pending_req = find_pending_request(s->sun_path, msg->name); if (pending_req) { @@ -301,11 +312,14 @@ process_msg(struct mp_msg_internal *m, struct sockaddr_un *s) if (pending_req->type == REQUEST_TYPE_SYNC) pthread_cond_signal(&pending_req->sync.cond); else if (pending_req->type == REQUEST_TYPE_ASYNC) - pthread_cond_signal( - &pending_requests.async_cond); + req = async_reply_handle_thread_unsafe( + pending_req); } else RTE_LOG(ERR, EAL, "Drop mp reply: %s\n", msg->name); pthread_mutex_unlock(&pending_requests.lock); + + if (req != NULL) + trigger_async_action(req); return; } @@ -365,7 +379,6 @@ timespec_cmp(const struct timespec *a, const struct timespec *b) } enum async_action { - ACTION_NONE, /**< don't do anything */ ACTION_FREE, /**< free the action entry, but don't trigger callback */ ACTION_TRIGGER /**< trigger callback, then free action entry */ }; @@ -375,7 +388,7 @@ process_async_request(struct pending_request *sr, const struct timespec *now) { struct async_request_param *param; struct rte_mp_reply *reply; - bool timeout, received, last_msg; + bool timeout, last_msg; param = sr->async.param; reply = ¶m->user_reply; @@ -383,13 +396,6 @@ process_async_request(struct pending_request *sr, const struct timespec *now) /* did we timeout? */ timeout = timespec_cmp(¶m->end, now) <= 0; - /* did we receive a response? */ - received = sr->reply_received != 0; - - /* if we didn't time out, and we didn't receive a response, ignore */ - if (!timeout && !received) - return ACTION_NONE; - /* if we received a response, adjust relevant data and copy mesasge. */ if (sr->reply_received == 1 && sr->reply) { struct rte_mp_msg *msg, *user_msgs, *tmp; @@ -448,118 +454,58 @@ trigger_async_action(struct pending_request *sr) free(sr->async.param->user_reply.msgs); free(sr->async.param); free(sr->request); + free(sr); } static struct pending_request * -check_trigger(struct timespec *ts) +async_reply_handle_thread_unsafe(void *arg) { - struct pending_request *next, *cur, *trigger = NULL; - - TAILQ_FOREACH_SAFE(cur, &pending_requests.requests, next, next) { - enum async_action action; - if (cur->type != REQUEST_TYPE_ASYNC) - continue; + struct pending_request *req = (struct pending_request *)arg; + enum async_action action; + struct timespec ts_now; + struct timeval now; - action = process_async_request(cur, ts); - if (action == ACTION_FREE) { - TAILQ_REMOVE(&pending_requests.requests, cur, next); - free(cur); - } else if (action == ACTION_TRIGGER) { - TAILQ_REMOVE(&pending_requests.requests, cur, next); - trigger = cur; - break; - } + if (gettimeofday(&now, NULL) < 0) { + RTE_LOG(ERR, EAL, "Cannot get current time\n"); + goto no_trigger; } - return trigger; -} + ts_now.tv_nsec = now.tv_usec * 1000; + ts_now.tv_sec = now.tv_sec; -static void -wait_for_async_messages(void) -{ - struct pending_request *sr; - struct timespec timeout; - bool timedwait = false; - bool nowait = false; - int ret; + action = process_async_request(req, &ts_now); - /* scan through the list and see if there are any timeouts that - * are earlier than our current timeout. - */ - TAILQ_FOREACH(sr, &pending_requests.requests, next) { - if (sr->type != REQUEST_TYPE_ASYNC) - continue; - if (!timedwait || timespec_cmp(&sr->async.param->end, - &timeout) < 0) { - memcpy(&timeout, &sr->async.param->end, - sizeof(timeout)); - timedwait = true; - } + TAILQ_REMOVE(&pending_requests.requests, req, next); - /* sometimes, we don't even wait */ - if (sr->reply_received) { - nowait = true; - break; + if (rte_eal_alarm_cancel(async_reply_handle, req) < 0) { + /* if we failed to cancel the alarm because it's already in + * progress, don't proceed because otherwise we will end up + * handling the same message twice. + */ + if (rte_errno == EINPROGRESS) { + RTE_LOG(DEBUG, EAL, "Request handling is already in progress\n"); + goto no_trigger; } + RTE_LOG(ERR, EAL, "Failed to cancel alarm\n"); } - if (nowait) - return; - - do { - ret = timedwait ? - pthread_cond_timedwait( - &pending_requests.async_cond, - &pending_requests.lock, - &timeout) : - pthread_cond_wait( - &pending_requests.async_cond, - &pending_requests.lock); - } while (ret != 0 && ret != ETIMEDOUT); - - /* we've been woken up or timed out */ + if (action == ACTION_TRIGGER) + return req; +no_trigger: + free(req); + return NULL; } -static void * -async_reply_handle(void *arg __rte_unused) +static void +async_reply_handle(void *arg) { - struct timeval now; - struct timespec ts_now; - while (1) { - struct pending_request *trigger = NULL; + struct pending_request *req; - pthread_mutex_lock(&pending_requests.lock); - - /* we exit this function holding the lock */ - wait_for_async_messages(); - - if (gettimeofday(&now, NULL) < 0) { - pthread_mutex_unlock(&pending_requests.lock); - RTE_LOG(ERR, EAL, "Cannot get current time\n"); - break; - } - ts_now.tv_nsec = now.tv_usec * 1000; - ts_now.tv_sec = now.tv_sec; - - do { - trigger = check_trigger(&ts_now); - /* unlock request list */ - pthread_mutex_unlock(&pending_requests.lock); - - if (trigger) { - trigger_async_action(trigger); - free(trigger); - - /* we've triggered a callback, but there may be - * more, so lock the list and check again. - */ - pthread_mutex_lock(&pending_requests.lock); - } - } while (trigger); - } - - RTE_LOG(ERR, EAL, "ERROR: asynchronous requests disabled\n"); + pthread_mutex_lock(&pending_requests.lock); + req = async_reply_handle_thread_unsafe(arg); + pthread_mutex_unlock(&pending_requests.lock); - return NULL; + if (req != NULL) + trigger_async_action(req); } static int @@ -624,7 +570,7 @@ rte_mp_channel_init(void) { char path[PATH_MAX]; int dir_fd; - pthread_t mp_handle_tid, async_reply_handle_tid; + pthread_t mp_handle_tid; /* create filter path */ create_socket_path("*", path, sizeof(path)); @@ -671,17 +617,6 @@ rte_mp_channel_init(void) return -1; } - if (rte_ctrl_thread_create(&async_reply_handle_tid, - "rte_mp_async", NULL, - async_reply_handle, NULL) < 0) { - RTE_LOG(ERR, EAL, "failed to create mp thead: %s\n", - strerror(errno)); - close(mp_fd); - close(dir_fd); - mp_fd = -1; - return -1; - } - /* unlock the directory */ flock(dir_fd, LOCK_UN); close(dir_fd); @@ -853,7 +788,7 @@ rte_mp_sendmsg(struct rte_mp_msg *msg) static int mp_request_async(const char *dst, struct rte_mp_msg *req, - struct async_request_param *param) + struct async_request_param *param, const struct timespec *ts) { struct rte_mp_msg *reply_msg; struct pending_request *pending_req, *exist; @@ -898,6 +833,13 @@ mp_request_async(const char *dst, struct rte_mp_msg *req, param->user_reply.nb_sent++; + if (rte_eal_alarm_set(ts->tv_sec * 1000000 + ts->tv_nsec / 1000, + async_reply_handle, pending_req) < 0) { + RTE_LOG(ERR, EAL, "Fail to set alarm for request %s:%s\n", + dst, req->name); + rte_panic("Fix the above shit to properly free all memory\n"); + } + return 0; fail: free(pending_req); @@ -1119,7 +1061,7 @@ rte_mp_request_async(struct rte_mp_msg *req, const struct timespec *ts, /* for secondary process, send request to the primary process only */ if (rte_eal_process_type() == RTE_PROC_SECONDARY) { - ret = mp_request_async(eal_mp_socket_path(), copy, param); + ret = mp_request_async(eal_mp_socket_path(), copy, param, ts); /* if we didn't send anything, put dummy request on the queue */ if (ret == 0 && reply->nb_sent == 0) { @@ -1162,7 +1104,7 @@ rte_mp_request_async(struct rte_mp_msg *req, const struct timespec *ts, snprintf(path, sizeof(path), "%s/%s", mp_dir_path, ent->d_name); - if (mp_request_async(path, copy, param)) + if (mp_request_async(path, copy, param, ts)) ret = -1; } /* if we didn't send anything, put dummy request on the queue */ @@ -1171,9 +1113,6 @@ rte_mp_request_async(struct rte_mp_msg *req, const struct timespec *ts, dummy_used = true; } - /* trigger async request thread wake up */ - pthread_cond_signal(&pending_requests.async_cond); - /* finally, unlock the queue */ pthread_mutex_unlock(&pending_requests.lock);