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 98C48A0093 for ; Thu, 23 Jun 2022 20:42:03 +0200 (CEST) Received: from [217.70.189.124] (localhost [127.0.0.1]) by mails.dpdk.org (Postfix) with ESMTP id 1A7934067B; Thu, 23 Jun 2022 20:42:03 +0200 (CEST) Received: from mail-pg1-f178.google.com (mail-pg1-f178.google.com [209.85.215.178]) by mails.dpdk.org (Postfix) with ESMTP id 7CEE440146 for ; Thu, 23 Jun 2022 20:42:02 +0200 (CEST) Received: by mail-pg1-f178.google.com with SMTP id l4so216250pgh.13 for ; Thu, 23 Jun 2022 11:42:02 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=networkplumber-org.20210112.gappssmtp.com; s=20210112; h=date:from:to:cc:subject:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=DN2JKH2eeZsOK6dLC8uiPMiXwapLxaxin/ERZFrRqJY=; b=OqXejIobmntEVllGJ3tTOziPUTgpJd0Gg/o37EdWujzbq/2XhHSCHKSSdkhmgFIqkU yFMp9jHROEhKYcbhnjrEf5GsRP4IK9rdGkcJQ00LucNQUiS0jOMWWeKsLJlYoJDZgQVK PjGhmZQ1bE4C5SCpdhfc5WOfV//FgeA5ezAq+fGbc26bjMLwlDeJraPSMMsiopn3Hgc3 FBcc2PQpRtSjGKe2MAkG7cyVNNEhjIW/IqbbNfSR1Mzj66lRPranveoqLkx+ZjPMNuG2 xgF3wBEf0GXKFdB6i/E61pUUlEbBJ5Iaors+izVhnEQlmBOU4WjYzbakdhS8vFWOToJp wMJQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:subject:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=DN2JKH2eeZsOK6dLC8uiPMiXwapLxaxin/ERZFrRqJY=; b=Keds2rOpfputxsqcafjDRqV+O6BN14ijdj5XJ97St0idPIDAldnAXn8ipyrUXr1Ncr 87aJ1boMHit8NMzhMFHjlUK8m+pQuPq0wbHQ7VmPNwMM/LNA2hf4lAO7Nq9tqZsa2s3l 2G6BbrWLdJEhj7btwOJFeNbAVNyx7ilbtmLeo33zRhpu/ByRSRghsTQcFP2VN4u0vWh+ Bodoly76retBcuTZujn3VP7vuCEtl7OWRAHXsfRkNYvL2Z0kx2OjH40PfkQEbV272yoA ej8+9s0BBJn8ln4DOoAkl20BXA4axHE2/pcmHe4luPXLFuHjimZndco2z8oTyPk58cFs F3vg== X-Gm-Message-State: AJIora/qWcXFahE1s1P2///xiZjo+kTmsg/Dk5Yjg+XP142QMkBoebwf OgIv2ULtez9HXMKBHoE+S4kupQ== X-Google-Smtp-Source: AGRyM1tYSZupkkXGIxanjz4ZUYLIh7gtPoGKhu44mtX1ikwrgOecw9WGx7MqN3l5vB/hbFV3rJ1F6g== X-Received: by 2002:a63:5108:0:b0:3fd:77f1:57a4 with SMTP id f8-20020a635108000000b003fd77f157a4mr8494461pgb.125.1656009721721; Thu, 23 Jun 2022 11:42:01 -0700 (PDT) Received: from hermes.local (204-195-112-199.wavecable.com. [204.195.112.199]) by smtp.gmail.com with ESMTPSA id h4-20020aa79f44000000b005253d045c97sm5578845pfr.49.2022.06.23.11.42.01 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 23 Jun 2022 11:42:01 -0700 (PDT) Date: Thu, 23 Jun 2022 11:41:59 -0700 From: Stephen Hemminger To: Antonio Di Bacco Cc: users@dpdk.org Subject: Re: Large interruptions for EAL thread running on isol core Message-ID: <20220623114159.0fb198b3@hermes.local> In-Reply-To: References: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-BeenThere: users@dpdk.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: DPDK usage discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: users-bounces@dpdk.org On Thu, 23 Jun 2022 20:03:02 +0200 Antonio Di Bacco wrote: > I'm running a DPDK thread on an isolated core. I also set some flags > that could help keeping the core at rest on linux like: nosoftlockup > nohz_full rcu_nocbs irqaffinity. > > Unfortunately the thread gets some interruptions that stop the thread > for about 20-30 micro seconds. This seems smal but my application > suffers a lot. > > I also tried to use rte_thread_set_priority that indeed has a strong > effect but unfortunately creates problems to Linux (like network not > working). > > Is there any other knob that could help running the DPDK thread with > minimum or no interruptions at all? Look with perf and see what is happening. First check for interrupt affinity. Don't try real time priority. The other thing to look for would be any BIOS settings. Some system management units can take away CPU silently for polling some internal housekeeping.