From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from dpdk.org (dpdk.org [92.243.14.124]) by inbox.dpdk.org (Postfix) with ESMTP id 4FDFAA0559; Tue, 17 Mar 2020 02:19:55 +0100 (CET) Received: from [92.243.14.124] (localhost [127.0.0.1]) by dpdk.org (Postfix) with ESMTP id 009101C10F; Tue, 17 Mar 2020 02:19:05 +0100 (CET) Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by dpdk.org (Postfix) with ESMTP id E71F91C0C9; Tue, 17 Mar 2020 02:19:03 +0100 (CET) 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 712451FB; Mon, 16 Mar 2020 18:19:03 -0700 (PDT) Received: from phil-VirtualBox.shanghai.arm.com (phil-VirtualBox.shanghai.arm.com [10.169.108.137]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 42CF83F52E; Mon, 16 Mar 2020 18:18:59 -0700 (PDT) From: Phil Yang To: thomas@monjalon.net, harry.van.haaren@intel.com, konstantin.ananyev@intel.com, stephen@networkplumber.org, maxime.coquelin@redhat.com, dev@dpdk.org Cc: david.marchand@redhat.com, jerinj@marvell.com, hemant.agrawal@nxp.com, Honnappa.Nagarahalli@arm.com, gavin.hu@arm.com, ruifeng.wang@arm.com, joyce.kong@arm.com, nd@arm.com, Honnappa Nagarahalli , stable@dpdk.org Date: Tue, 17 Mar 2020 09:17:40 +0800 Message-Id: <1584407863-774-10-git-send-email-phil.yang@arm.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1584407863-774-1-git-send-email-phil.yang@arm.com> References: <1583999071-22872-1-git-send-email-phil.yang@arm.com> <1584407863-774-1-git-send-email-phil.yang@arm.com> Subject: [dpdk-dev] [PATCH v3 09/12] service: avoid race condition for MT unsafe service X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 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" From: Honnappa Nagarahalli There has possible that a MT unsafe service might get configured to run on another core while the service is running currently. This might result in the MT unsafe service running on multiple cores simultaneously. Use 'execute_lock' always when the service is MT unsafe. Fixes: e9139a32f6e8 ("service: add function to run on app lcore") Cc: stable@dpdk.org Signed-off-by: Honnappa Nagarahalli Reviewed-by: Phil Yang Reviewed-by: Gavin Hu --- lib/librte_eal/common/rte_service.c | 11 +++++------ 1 file changed, 5 insertions(+), 6 deletions(-) diff --git a/lib/librte_eal/common/rte_service.c b/lib/librte_eal/common/rte_service.c index 557b5a9..32a2f8a 100644 --- a/lib/librte_eal/common/rte_service.c +++ b/lib/librte_eal/common/rte_service.c @@ -50,6 +50,10 @@ struct rte_service_spec_impl { uint8_t internal_flags; /* per service statistics */ + /* Indicates how many cores the service is mapped to run on. + * It does not indicate the number of cores the service is running + * on currently. + */ rte_atomic32_t num_mapped_cores; uint64_t calls; uint64_t cycles_spent; @@ -370,12 +374,7 @@ service_run(uint32_t i, struct core_state *cs, uint64_t service_mask, cs->service_active_on_lcore[i] = 1; - /* check do we need cmpset, if MT safe or <= 1 core - * mapped, atomic ops are not required. - */ - const int use_atomics = (service_mt_safe(s) == 0) && - (rte_atomic32_read(&s->num_mapped_cores) > 1); - if (use_atomics) { + if (service_mt_safe(s) == 0) { if (!rte_atomic32_cmpset((uint32_t *)&s->execute_lock, 0, 1)) return -EBUSY; -- 2.7.4