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 BCCB645C6C; Sun, 3 Nov 2024 12:25:40 +0100 (CET) Received: from mails.dpdk.org (localhost [127.0.0.1]) by mails.dpdk.org (Postfix) with ESMTP id AD8E2402A3; Sun, 3 Nov 2024 12:25:40 +0100 (CET) Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by mails.dpdk.org (Postfix) with ESMTP id C87D94021F for ; Sun, 3 Nov 2024 12:25:38 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1730633138; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=yOcV8PiwGylrtMGJ0gvuWHCSXw/bGr/+w5WjY4YSNco=; b=aHP/mxk3O52Rssmd+gatVhGweRGz1sLQ0efL7vfzd3AzHmmqr81zbii4w33Oh0c3lkG7ZA jxVqtDaqwIxrJGIwBdocEf5kEGv1kwZn6TDur3VZ0z7Ck4qwL4thFzAFDMIRmyyQdZEG8D LKFAxz64iPoA959Ijp2s5sSWOY/Rzv4= Received: from mx-prod-mc-04.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-669-ahcfeXbZNH2_mdL2aXkvYA-1; Sun, 03 Nov 2024 06:25:29 -0500 X-MC-Unique: ahcfeXbZNH2_mdL2aXkvYA-1 Received: from mx-prod-int-04.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-04.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.40]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-04.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id D0CFC19560A3; Sun, 3 Nov 2024 11:25:27 +0000 (UTC) Received: from dmarchan.redhat.com (unknown [10.45.224.57]) by mx-prod-int-04.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 41BA119560AD; Sun, 3 Nov 2024 11:25:24 +0000 (UTC) From: David Marchand To: dev@dpdk.org Cc: thomas@monjalon.net, stephen@networkplumber.org, luca.boccassi@gmail.com, stable@dpdk.org, Luca Boccassi , Tyler Retzlaff Subject: [PATCH v3] eal/unix: optimize thread creation with glibc Date: Sun, 3 Nov 2024 12:25:19 +0100 Message-ID: <20241103112519.2972691-1-david.marchand@redhat.com> In-Reply-To: <20241102100839.2325651-1-david.marchand@redhat.com> References: <20241102100839.2325651-1-david.marchand@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.0 on 10.30.177.40 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset="US-ASCII"; x-default=true 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 Setting the cpu affinity of the child thread from the parent thread is racy when using pthread_setaffinity_np, as the child thread may start running and initialize before affinity is set. On the other hand, setting the cpu affinity from the child thread itself may fail, so the parent thread waits for the child thread to report whether this call succeeded. This synchronisation point resulted in a significant slow down of rte_thread_create() (as seen in the lcores_autotest unit tests, in OBS for some ARM systems). Another option for setting cpu affinity is to use the not portable pthread_attr_setaffinity_np, but it is not available with musl. Fixes: b28c6196b132 ("eal/unix: fix thread creation") Cc: stable@dpdk.org Signed-off-by: David Marchand Acked-by: Luca Boccassi --- Changes since v2: - added pthread_attr_setaffinity_np() detection, Changes since v1: - fixed build with FreeBSD, --- lib/eal/unix/meson.build | 5 +++++ lib/eal/unix/rte_thread.c | 25 +++++++++++++++++++++++++ 2 files changed, 30 insertions(+) diff --git a/lib/eal/unix/meson.build b/lib/eal/unix/meson.build index cc7d67dd32..f845625a54 100644 --- a/lib/eal/unix/meson.build +++ b/lib/eal/unix/meson.build @@ -11,3 +11,8 @@ sources += files( 'eal_unix_timer.c', 'rte_thread.c', ) + +if cc.has_function('pthread_attr_setaffinity_np', args: '-D_GNU_SOURCE', + prefix : '#include ') + cflags += '-DRTE_EAL_PTHREAD_ATTR_SETAFFINITY_NP' +endif diff --git a/lib/eal/unix/rte_thread.c b/lib/eal/unix/rte_thread.c index 1b4c73f58e..ea629c2065 100644 --- a/lib/eal/unix/rte_thread.c +++ b/lib/eal/unix/rte_thread.c @@ -19,6 +19,7 @@ struct eal_tls_key { pthread_key_t thread_index; }; +#ifndef RTE_EAL_PTHREAD_ATTR_SETAFFINITY_NP struct thread_start_context { rte_thread_func thread_func; void *thread_args; @@ -28,6 +29,7 @@ struct thread_start_context { int wrapper_ret; bool wrapper_done; }; +#endif static int thread_map_priority_to_os_value(enum rte_thread_priority eal_pri, int *os_pri, @@ -88,6 +90,7 @@ thread_map_os_priority_to_eal_priority(int policy, int os_pri, return 0; } +#ifndef RTE_EAL_PTHREAD_ATTR_SETAFFINITY_NP static void * thread_start_wrapper(void *arg) { @@ -113,6 +116,7 @@ thread_start_wrapper(void *arg) return (void *)(uintptr_t)thread_func(thread_args); } +#endif int rte_thread_create(rte_thread_t *thread_id, @@ -126,6 +130,7 @@ rte_thread_create(rte_thread_t *thread_id, .sched_priority = 0, }; int policy = SCHED_OTHER; +#ifndef RTE_EAL_PTHREAD_ATTR_SETAFFINITY_NP struct thread_start_context ctx = { .thread_func = thread_func, .thread_args = args, @@ -134,6 +139,7 @@ rte_thread_create(rte_thread_t *thread_id, .wrapper_mutex = PTHREAD_MUTEX_INITIALIZER, .wrapper_cond = PTHREAD_COND_INITIALIZER, }; +#endif if (thread_attr != NULL) { ret = pthread_attr_init(&attr); @@ -144,6 +150,16 @@ rte_thread_create(rte_thread_t *thread_id, attrp = &attr; +#ifdef RTE_EAL_PTHREAD_ATTR_SETAFFINITY_NP + if (CPU_COUNT(&thread_attr->cpuset) > 0) { + ret = pthread_attr_setaffinity_np(attrp, sizeof(thread_attr->cpuset), + &thread_attr->cpuset); + if (ret != 0) { + EAL_LOG(DEBUG, "pthread_attr_setaffinity_np failed"); + goto cleanup; + } + } +#endif /* * Set the inherit scheduler parameter to explicit, * otherwise the priority attribute is ignored. @@ -178,6 +194,14 @@ rte_thread_create(rte_thread_t *thread_id, } } +#ifdef RTE_EAL_PTHREAD_ATTR_SETAFFINITY_NP + ret = pthread_create((pthread_t *)&thread_id->opaque_id, attrp, + (void *)(void *)thread_func, args); + if (ret != 0) { + EAL_LOG(DEBUG, "pthread_create failed"); + goto cleanup; + } +#else /* !RTE_EAL_PTHREAD_ATTR_SETAFFINITY_NP */ ret = pthread_create((pthread_t *)&thread_id->opaque_id, attrp, thread_start_wrapper, &ctx); if (ret != 0) { @@ -193,6 +217,7 @@ rte_thread_create(rte_thread_t *thread_id, if (ret != 0) rte_thread_join(*thread_id, NULL); +#endif /* RTE_EAL_PTHREAD_ATTR_SETAFFINITY_NP */ cleanup: if (attrp != NULL) -- 2.46.2