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 0E4C4459C6 for ; Thu, 19 Sep 2024 01:27:45 +0200 (CEST) Received: from mails.dpdk.org (localhost [127.0.0.1]) by mails.dpdk.org (Postfix) with ESMTP id C447A40156; Thu, 19 Sep 2024 01:27:44 +0200 (CEST) Received: from mail-pg1-f175.google.com (mail-pg1-f175.google.com [209.85.215.175]) by mails.dpdk.org (Postfix) with ESMTP id 4AFF14003C for ; Thu, 19 Sep 2024 01:27:43 +0200 (CEST) Received: by mail-pg1-f175.google.com with SMTP id 41be03b00d2f7-7d50e7a3652so103350a12.3 for ; Wed, 18 Sep 2024 16:27:43 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=networkplumber-org.20230601.gappssmtp.com; s=20230601; t=1726702062; x=1727306862; darn=dpdk.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:subject:cc:to:from:date:from:to:cc:subject:date :message-id:reply-to; bh=g1bwUxvRXlD/boUQ8V9nN4VlzNRlG70nCfVNif6PDI0=; b=L8LSEaYigon3fuuyHqzIY84mW4GqLqYDeDwtUXhxYpWxJvUi4YI7RnKy1Jb35/EOEE eKVJ1g9uhvw4CKSjaJn2pMh/xRaphcEbjJgJ4a7OLIdpbkLsRdsARbQUCn/9225KYdtJ 2T+YsTJzsgVj9n4qm9m4dnccUPKAUWD/mZiaXjRix0D2xKdhKMYa1CO2GL58AzkLmvGv XM7bBK/C3R1s90jcIOKIAeJ2mLGLzkhOmldGBHt0DDPyywo8hpzGf6rcq48DHD8DgHUQ OTjA39BaphMhsMpgcjDj/ABBU0T/d1E6OAixWgybZby48YWGmTvLhsnyiOJXnAKx1vji S9RQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1726702062; x=1727306862; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:subject:cc:to:from:date:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=g1bwUxvRXlD/boUQ8V9nN4VlzNRlG70nCfVNif6PDI0=; b=lroNO4bJGNlqe/ZB/n6xo8Xk+x6b3CJw7CKIV88XAo4SBrg9CO5yMgJJzPIn24TRlL WYlhO/u/v8S2mF5MA8PeuN9d2dBQPNeVRJR5I1PSWMrKKL2cOv66IHociu2Mzk9k2HdI nO55lFeOhiNSEmwm1RFcq/ZWGbOhAed/r+WozLJIrAkrTainDTgY3WzptrJ7WoRorABe C1CS7Lu9g6adTHwdkx1tCfZ+qgBDqUFt0mcANiymFAd6GiTPBXZq73zBkwqaJpmYd5Zj vONDG02ZPlnoisRQsH+PdKoE3aaamXhB+SKYj9KAdz5iLpdJdX0be9jlkY3uXcdphMPG UjvQ== X-Gm-Message-State: AOJu0Yy9R0N9Cx2c5Wd5M4UUs5nnq1W17pMeDivdzeUSqB/DRDnJtAKS kh6Zj41VwQZ+VuwWuuPSIamwibjT+LYhzo9X2JRUFenvRClVrMQfhLpSeowzaCs= X-Google-Smtp-Source: AGHT+IG6LYrgt11jed3jv8ZispGTSI+5nN3puSKZBq5/6JdCx51JC1k3W2Af2orIGtcSkryraLKAog== X-Received: by 2002:a05:6a20:c781:b0:1cf:4da0:d95c with SMTP id adf61e73a8af0-1cf75f00582mr37862623637.23.1726702062051; Wed, 18 Sep 2024 16:27:42 -0700 (PDT) Received: from hermes.local (204-195-96-226.wavecable.com. [204.195.96.226]) by smtp.gmail.com with ESMTPSA id d2e1a72fcca58-71944a9ca91sm7426617b3a.17.2024.09.18.16.27.41 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 18 Sep 2024 16:27:41 -0700 (PDT) Date: Wed, 18 Sep 2024 16:27:39 -0700 From: Stephen Hemminger To: Isaac Boukris Cc: users@dpdk.org Subject: Re: Accuracy of rte_get_tsc_hz() compared to linux Message-ID: <20240918162739.144ffd9d@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, 19 Sep 2024 01:04:40 +0300 Isaac Boukris wrote: > I've run the helloworld application on an isolated cpu: > taskset -c 10 ./dpdk-helloworld --log-level=lib.eal:debug --no-huge > > The results are: > EAL: TSC frequency arch ~2100000 KHz > EAL: TSC frequency linux ~2095082 KHz > EAL: TSC frequency estimate ~2095346 KHz > > The arch one is picked, which seems rather wrong, any way to override that? > Should we lower the estimation rounding to 1MHz or even 1KHz in the linux one? > > Thoughts? Thanks! > > Kernel: 4.18.0-513.9.1.el8_9.x86_64 Note: 4.18 kernel was end of life 12 August 2018, I assume this is RHEL8 which does their own backports and never changes kernel version. What is the kernel dmesg, why is it deciding on that value?