From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mails.dpdk.org (mails.dpdk.org [217.70.189.124]) by inbox.dpdk.org (Postfix) with ESMTP id 69D7BA0C43; Thu, 21 Oct 2021 23:32:30 +0200 (CEST) Received: from [217.70.189.124] (localhost [127.0.0.1]) by mails.dpdk.org (Postfix) with ESMTP id 2264040040; Thu, 21 Oct 2021 23:32:30 +0200 (CEST) Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by mails.dpdk.org (Postfix) with ESMTP id BB36F4003F for ; Thu, 21 Oct 2021 23:32:28 +0200 (CEST) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 388F0D6E; Thu, 21 Oct 2021 14:32:28 -0700 (PDT) Received: from qc2400f-1.austin.arm.com (qc2400f-1.austin.arm.com [10.118.12.44]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 2BB953F73D; Thu, 21 Oct 2021 14:32:28 -0700 (PDT) From: Honnappa Nagarahalli To: dev@dpdk.org, honnappa.nagarahalli@arm.com, olivier.matz@6wind.com, lucp.at.work@gmail.com, stephen@networkplumber.org, david.marchand@redhat.com, thomas@monjalon.net Cc: ruifeng.wang@arm.com, nd@arm.com Date: Thu, 21 Oct 2021 16:32:20 -0500 Message-Id: <20211021213221.9239-1-honnappa.nagarahalli@arm.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20210730213709.19400-1-honnappa.nagarahalli@arm.com> References: <20210730213709.19400-1-honnappa.nagarahalli@arm.com> Subject: [dpdk-dev] [PATCH v5 1/2] eal: simplify the implementation of rte_ctrl_thread_create X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Sender: "dev" Remove the usage of pthread barrier and replace it with synchronization using atomic variable. This also removes the use of reference count required to synchronize freeing the memory. Signed-off-by: Honnappa Nagarahalli Reviewed-by: Olivier Matz --- lib/eal/common/eal_common_thread.c | 87 +++++++++++++++--------------- lib/eal/include/rte_lcore.h | 9 ++-- 2 files changed, 50 insertions(+), 46 deletions(-) diff --git a/lib/eal/common/eal_common_thread.c b/lib/eal/common/eal_common_thread.c index 1a52f42a2b..c602bd2a0d 100644 --- a/lib/eal/common/eal_common_thread.c +++ b/lib/eal/common/eal_common_thread.c @@ -166,38 +166,44 @@ __rte_thread_uninit(void) RTE_PER_LCORE(_lcore_id) = LCORE_ID_ANY; } +enum __rte_ctrl_thread_status { + CTRL_THREAD_LAUNCHING, /* Yet to call pthread_create function */ + CTRL_THREAD_RUNNING, /* Control thread is running successfully */ + CTRL_THREAD_ERROR /* Control thread encountered an error */ +}; + struct rte_thread_ctrl_params { void *(*start_routine)(void *); void *arg; - pthread_barrier_t configured; - unsigned int refcnt; + int ret; + /* Control thread status. If the status is CTRL_THREAD_ERROR + * 'ret' has the error code. + */ + enum __rte_ctrl_thread_status ctrl_thread_status; }; -static void ctrl_params_free(struct rte_thread_ctrl_params *params) -{ - if (__atomic_sub_fetch(¶ms->refcnt, 1, __ATOMIC_ACQ_REL) == 0) { - (void)pthread_barrier_destroy(¶ms->configured); - free(params); - } -} - static void *ctrl_thread_init(void *arg) { struct internal_config *internal_conf = eal_get_internal_configuration(); rte_cpuset_t *cpuset = &internal_conf->ctrl_cpuset; struct rte_thread_ctrl_params *params = arg; - void *(*start_routine)(void *); + void *(*start_routine)(void *) = params->start_routine; void *routine_arg = params->arg; __rte_thread_init(rte_lcore_id(), cpuset); - - pthread_barrier_wait(¶ms->configured); - start_routine = params->start_routine; - ctrl_params_free(params); - - if (start_routine == NULL) + params->ret = pthread_setaffinity_np(pthread_self(), + sizeof(*cpuset), cpuset); + if (params->ret != 0) { + __atomic_store_n(¶ms->ctrl_thread_status, + CTRL_THREAD_ERROR, + __ATOMIC_RELEASE); return NULL; + } + + __atomic_store_n(¶ms->ctrl_thread_status, + CTRL_THREAD_RUNNING, + __ATOMIC_RELEASE); return start_routine(routine_arg); } @@ -207,10 +213,8 @@ rte_ctrl_thread_create(pthread_t *thread, const char *name, const pthread_attr_t *attr, void *(*start_routine)(void *), void *arg) { - struct internal_config *internal_conf = - eal_get_internal_configuration(); - rte_cpuset_t *cpuset = &internal_conf->ctrl_cpuset; struct rte_thread_ctrl_params *params; + enum __rte_ctrl_thread_status ctrl_thread_status; int ret; params = malloc(sizeof(*params)); @@ -219,15 +223,14 @@ rte_ctrl_thread_create(pthread_t *thread, const char *name, params->start_routine = start_routine; params->arg = arg; - params->refcnt = 2; - - ret = pthread_barrier_init(¶ms->configured, NULL, 2); - if (ret != 0) - goto fail_no_barrier; + params->ret = 0; + params->ctrl_thread_status = CTRL_THREAD_LAUNCHING; ret = pthread_create(thread, attr, ctrl_thread_init, (void *)params); - if (ret != 0) - goto fail_with_barrier; + if (ret != 0) { + free(params); + return -ret; + } if (name != NULL) { ret = rte_thread_setname(*thread, name); @@ -236,24 +239,24 @@ rte_ctrl_thread_create(pthread_t *thread, const char *name, "Cannot set name for ctrl thread\n"); } - ret = pthread_setaffinity_np(*thread, sizeof(*cpuset), cpuset); - if (ret != 0) - params->start_routine = NULL; - - pthread_barrier_wait(¶ms->configured); - ctrl_params_free(params); + /* Wait for the control thread to initialize successfully */ + while ((ctrl_thread_status = + __atomic_load_n(¶ms->ctrl_thread_status, __ATOMIC_ACQUIRE)) + == CTRL_THREAD_LAUNCHING) { + /* Yield the CPU. Using sched_yield call requires maintaining + * another implementation for Windows as sched_yield is not + * supported on Windows. + */ + rte_delay_us_sleep(1); + } - if (ret != 0) - /* start_routine has been set to NULL above; */ - /* ctrl thread will exit immediately */ + /* Check if the control thread encountered an error */ + if (ctrl_thread_status == CTRL_THREAD_ERROR) { + /* ctrl thread is exiting */ pthread_join(*thread, NULL); + } - return -ret; - -fail_with_barrier: - (void)pthread_barrier_destroy(¶ms->configured); - -fail_no_barrier: + ret = params->ret; free(params); return -ret; diff --git a/lib/eal/include/rte_lcore.h b/lib/eal/include/rte_lcore.h index 1550b75da0..b81c8b2685 100644 --- a/lib/eal/include/rte_lcore.h +++ b/lib/eal/include/rte_lcore.h @@ -420,10 +420,11 @@ rte_thread_unregister(void); /** * Create a control thread. * - * Wrapper to pthread_create(), pthread_setname_np() and - * pthread_setaffinity_np(). The affinity of the new thread is based - * on the CPU affinity retrieved at the time rte_eal_init() was called, - * the dataplane and service lcores are then excluded. + * Creates a control thread with the given name and attributes. The + * affinity of the new thread is based on the CPU affinity retrieved + * at the time rte_eal_init() was called, the dataplane and service + * lcores are then excluded. If setting the name of the thread fails, + * the error is ignored and a debug message is logged. * * @param thread * Filled with the thread id of the new created thread. -- 2.25.1