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 7A0FCA034E; Thu, 23 Apr 2020 18:32:10 +0200 (CEST) Received: from [92.243.14.124] (localhost [127.0.0.1]) by dpdk.org (Postfix) with ESMTP id 35EE71D161; Thu, 23 Apr 2020 18:32:01 +0200 (CEST) Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by dpdk.org (Postfix) with ESMTP id 84B211D152; Thu, 23 Apr 2020 18:31:59 +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 0E67730E; Thu, 23 Apr 2020 09:31:59 -0700 (PDT) Received: from phil-VirtualBox.arm.com (A010647.Arm.com [10.170.243.60]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id E1BD33F68F; Thu, 23 Apr 2020 09:31:55 -0700 (PDT) From: Phil Yang To: harry.van.haaren@intel.com, dev@dpdk.org Cc: thomas@monjalon.net, david.marchand@redhat.com, konstantin.ananyev@intel.com, jerinj@marvell.com, hemant.agrawal@nxp.com, Honnappa.Nagarahalli@arm.com, gavin.hu@arm.com, nd@arm.com, Honnappa Nagarahalli , stable@dpdk.org Date: Fri, 24 Apr 2020 00:31:17 +0800 Message-Id: <1587659482-27133-2-git-send-email-phil.yang@arm.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1587659482-27133-1-git-send-email-phil.yang@arm.com> References: <1584407863-774-8-git-send-email-phil.yang@arm.com> <1587659482-27133-1-git-send-email-phil.yang@arm.com> Subject: [dpdk-dev] [PATCH v2 1/6] service: fix 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 The 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 --- 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 70d17a5..b8c465e 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