From patchwork Wed May 6 10:24:39 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Phil Yang X-Patchwork-Id: 186245 Delivered-To: patch@linaro.org Received: by 2002:a92:8d81:0:0:0:0:0 with SMTP id w1csp1977037ill; Wed, 6 May 2020 03:26:00 -0700 (PDT) X-Google-Smtp-Source: APiQypIOdk9qNaxNu9ErfNq2y0bA37cG47Vt7qdBaDhsdSCbvBirqYRo5b4rWtESbW4zRFyhpt8w X-Received: by 2002:a50:ef18:: with SMTP id m24mr6098343eds.281.1588760760574; Wed, 06 May 2020 03:26:00 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1588760760; cv=none; d=google.com; s=arc-20160816; b=GeFNpVW8AveEzqaeqD983yl0aKrsmVvdsyROjX1V7avLYhKZbrxLkTKfigDTNJLFwH fHF/xkOSIVUsUXek98OfUk+gnwvT696PYOmYoymT/HGe7Dn41yce3kSdAGtE/ZrRfO8o rPD/jJeBPkUOjXGHvK6k4PKTAOBKJThmpWaoSbQQriEzpie+rggYiJgqo4BtYhvZLyat ea7gDoubqss1V1Lzdd0WF8VQcf/faWZ9yDbIfP6LsEEVcnHKuDKeIVNhXvodJImL9P5A 4nEza+jVYi9HnSp6LU9kvPhDZjO+VJyEFj18D3bPCisO0nvZA+FPQUFYF5sGGIsrzdVr 328g== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=sender:errors-to:list-subscribe:list-help:list-post:list-archive :list-unsubscribe:list-id:precedence:subject:references:in-reply-to :message-id:date:cc:to:from; bh=XyTHIG8Yut73x3x/VmRXUpkJ2sjyF1Tfn/QgMrfIhh0=; b=1Hj7gQoGYKqbR2ccJnWGozS+894M8sGXnqSzpOHhIgvpgs/5EX4EX0AIufMc5XsWKd 8fWo6o9vBFE9mGQCB6YegqRG+hH1VOZSzYoPo6NG6BjUsuCrKwz4fzfLGlXyjJu5lQIw 3ci/HNQhPodsdp4mlCmzRycGx2EGhxhuY2eaDyC9Mw5dD2HDzomblciSoFC6Mkmts3N0 2rdEqCjff8x1QvyibgIgGNi6ChZiYGQDATw4RDZaX5kC+kfvgfXGecNtLYsP/P/hL36Q +T8Idk0th+yln1EKO2eJRm0uZy77PvjgmmTUe3VO7SSj0HmID2qUjBso9eRAOr4SGSal ZKpg== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: domain of dev-bounces@dpdk.org designates 92.243.14.124 as permitted sender) smtp.mailfrom=dev-bounces@dpdk.org Return-Path: Received: from dpdk.org (dpdk.org. [92.243.14.124]) by mx.google.com with ESMTP id d20si792283edz.32.2020.05.06.03.26.00; Wed, 06 May 2020 03:26:00 -0700 (PDT) Received-SPF: pass (google.com: domain of dev-bounces@dpdk.org designates 92.243.14.124 as permitted sender) client-ip=92.243.14.124; Authentication-Results: mx.google.com; spf=pass (google.com: domain of dev-bounces@dpdk.org designates 92.243.14.124 as permitted sender) smtp.mailfrom=dev-bounces@dpdk.org Received: from [92.243.14.124] (localhost [127.0.0.1]) by dpdk.org (Postfix) with ESMTP id ED6D71D907; Wed, 6 May 2020 12:25:57 +0200 (CEST) Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by dpdk.org (Postfix) with ESMTP id BF5F81D8FF; Wed, 6 May 2020 12:25:56 +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 47FD130E; Wed, 6 May 2020 03:25:56 -0700 (PDT) Received: from phil-VirtualBox.shanghai.arm.com (phil-VirtualBox.shanghai.arm.com [10.169.108.145]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id DCFF93F71F; Wed, 6 May 2020 03:25:52 -0700 (PDT) From: Phil Yang To: dev@dpdk.org, harry.van.haaren@intel.com Cc: thomas@monjalon.net, david.marchand@redhat.com, konstantin.ananyev@intel.com, jerinj@marvell.com, hemant.agrawal@nxp.com, gage.eads@intel.com, bruce.richardson@intel.com, Honnappa.Nagarahalli@arm.com, nd@arm.com, Honnappa Nagarahalli , stable@dpdk.org Date: Wed, 6 May 2020 18:24:39 +0800 Message-Id: <1588760683-11027-3-git-send-email-phil.yang@arm.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1588760683-11027-1-git-send-email-phil.yang@arm.com> References: <20200505211732.25291-1-honnappa.nagarahalli@arm.com> <1588760683-11027-1-git-send-email-phil.yang@arm.com> Subject: [dpdk-dev] [PATCH v5 2/6] service: fix identification of service running on other lcore 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 logic to identify if the MT unsafe service is running on another core can return -EBUSY spuriously. In such cases, running the service becomes costlier than using atomic operations. Assume that the application passes the right parameters and reduce the number of instructions for all cases. Cc: stable@dpdk.org Fixes: 8d39d3e237c2 ("service: fix race in service on app lcore function") Signed-off-by: Honnappa Nagarahalli Reviewed-by: Phil Yang Acked-by: Harry van Haaren --- lib/librte_eal/common/rte_service.c | 26 ++++++++------------------ 1 file changed, 8 insertions(+), 18 deletions(-) -- 2.7.4 diff --git a/lib/librte_eal/common/rte_service.c b/lib/librte_eal/common/rte_service.c index b8c465e..c283408 100644 --- a/lib/librte_eal/common/rte_service.c +++ b/lib/librte_eal/common/rte_service.c @@ -360,7 +360,7 @@ rte_service_runner_do_callback(struct rte_service_spec_impl *s, /* Expects the service 's' is valid. */ static int32_t service_run(uint32_t i, struct core_state *cs, uint64_t service_mask, - struct rte_service_spec_impl *s) + struct rte_service_spec_impl *s, uint32_t serialize_mt_unsafe) { if (!s) return -EINVAL; @@ -374,7 +374,7 @@ service_run(uint32_t i, struct core_state *cs, uint64_t service_mask, cs->service_active_on_lcore[i] = 1; - if (service_mt_safe(s) == 0) { + if ((service_mt_safe(s) == 0) && (serialize_mt_unsafe == 1)) { if (!rte_atomic32_cmpset((uint32_t *)&s->execute_lock, 0, 1)) return -EBUSY; @@ -412,24 +412,14 @@ rte_service_run_iter_on_app_lcore(uint32_t id, uint32_t serialize_mt_unsafe) SERVICE_VALID_GET_OR_ERR_RET(id, s, -EINVAL); - /* Atomically add this core to the mapped cores first, then examine if - * we can run the service. This avoids a race condition between - * checking the value, and atomically adding to the mapped count. + /* Increment num_mapped_cores to reflect that this core is + * now mapped capable of running the service. */ - if (serialize_mt_unsafe) - rte_atomic32_inc(&s->num_mapped_cores); + rte_atomic32_inc(&s->num_mapped_cores); - if (service_mt_safe(s) == 0 && - rte_atomic32_read(&s->num_mapped_cores) > 1) { - if (serialize_mt_unsafe) - rte_atomic32_dec(&s->num_mapped_cores); - return -EBUSY; - } - - int ret = service_run(id, cs, UINT64_MAX, s); + int ret = service_run(id, cs, UINT64_MAX, s, serialize_mt_unsafe); - if (serialize_mt_unsafe) - rte_atomic32_dec(&s->num_mapped_cores); + rte_atomic32_dec(&s->num_mapped_cores); return ret; } @@ -449,7 +439,7 @@ rte_service_runner_func(void *arg) if (!service_valid(i)) continue; /* return value ignored as no change to code flow */ - service_run(i, cs, service_mask, service_get(i)); + service_run(i, cs, service_mask, service_get(i), 1); } cs->loops++;