From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.3 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2E1ECC433B4 for ; Tue, 11 May 2021 19:50:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E701961376 for ; Tue, 11 May 2021 19:50:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232192AbhEKTvg (ORCPT ); Tue, 11 May 2021 15:51:36 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37388 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232234AbhEKTv2 (ORCPT ); Tue, 11 May 2021 15:51:28 -0400 Received: from mail-ej1-x634.google.com (mail-ej1-x634.google.com [IPv6:2a00:1450:4864:20::634]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id F0207C061574 for ; Tue, 11 May 2021 12:50:20 -0700 (PDT) Received: by mail-ej1-x634.google.com with SMTP id j10so4474315ejb.3 for ; Tue, 11 May 2021 12:50:20 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=subject:to:references:from:message-id:date:user-agent:mime-version :in-reply-to:content-transfer-encoding; bh=zFdRi+JcQXMLUvHeiOf5oF71WE5nwWbz/byLlhDQ9UY=; b=ACLPkt1+a/AXRsLX7L6Lnd0YX/C82FRYTURLgD1T9E04h1zXISkDs43fySZJHJ2o4q dWMR889iOC7Dl3K/7SzVIQr/hScIxB2iXfrBHdKC2uE+URnv13hsQS+lTJQPj3+xnJ9k rj10WcUxAA/5RPI0x6rx710Sqxfpj6e5Gj4a2W01DChRAsFNa/sOF5j2P0d8EOO6KROn rqycOeGnRqVNRc8mcq3hQktl9SI+/twQq8k5bosRmEgSm6DQz4dVsbfdhAxZN1RVxgKP XtalkJTx9iljW1yvMpsZdmutkYm5L4eTus3JObC43Eu5Ng3o5/tjyoT1zFzZb3vP4M4r GJdQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-transfer-encoding; bh=zFdRi+JcQXMLUvHeiOf5oF71WE5nwWbz/byLlhDQ9UY=; b=CSZDRwphggW0FN7hNPRFTY2W5bhS5xSdFj1sawMMpa36gkYMSFAJHwOnZ5vICfODog NVmd0b3YvzJjGnsl79j+ORGQPvPb658YtieIH9nENQ6mX8+nOVU6ctwxd6+z+IFEoLqk 3+kqh6SA05Qz5TKANkRZEXthRJBgBSK22RKjh4AHovieL6wP39IaZIz5ptSNkn4x1AxS pzW/XYK9wrRN2kaLyLVsO9G1L9NnjY79xyBWidv+pQ+Ch+0xdNmU0byHzyOUyEcVYFAR SoyrOxZSQ/EJ5Kotkkw7i1l9L2Sw2WyKjc9yraqaK3XO5c8A/g1t357SeUUJ5c5ge6sJ /NaA== X-Gm-Message-State: AOAM533n6J08fZrpLU6N/aygAocE6jjDMehzdhBuLGMLkVVAZR5tYvn/ X8GZjP5w2wIjriOadCB9crMm6MS8zCk= X-Google-Smtp-Source: ABdhPJxM+FnA/272H1xzHnEv1KctCs7xo6DiVBTFKpjmCSnQCgMRmPmPKTZlsfS0oB7+E1+2z1vQdQ== X-Received: by 2002:a17:906:b315:: with SMTP id n21mr33424283ejz.219.1620762619328; Tue, 11 May 2021 12:50:19 -0700 (PDT) Received: from ?IPv6:2a01:c23:7094:5a00:c90f:e684:6fe8:2cfb? (dynamic-2a01-0c23-7094-5a00-c90f-e684-6fe8-2cfb.c23.pool.telefonica.de. [2a01:c23:7094:5a00:c90f:e684:6fe8:2cfb]) by smtp.gmail.com with ESMTPSA id p25sm1033088eja.35.2021.05.11.12.50.18 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 11 May 2021 12:50:18 -0700 (PDT) Subject: Re: big rt latencies compared to non rt To: Angelo Dureghello , linux-rt-users@vger.kernel.org References: <736a53fb-d80e-3faa-1a66-d40538e0fe26@kernel-space.org> From: Jonathan Schwender Message-ID: <80987725-41e4-017c-5e20-dbd886726ee9@gmail.com> Date: Tue, 11 May 2021 21:50:17 +0200 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.9.1 MIME-Version: 1.0 In-Reply-To: <736a53fb-d80e-3faa-1a66-d40538e0fe26@kernel-space.org> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-rt-users@vger.kernel.org Hi Angelo, > > Average is near 16uS but there are some outside > values near 40000, as You are reading the table wrong. The leftmost column is the microsecond bucket. The other columns give the amount of times a latency was inside that microsecond bucket for each measurement thread. > 000017 040537    015000    033773    041092  <----- For example, in this line CPU 0 had 40537 latencies in the 17 us bucket, while CPU 1 had 15000 measured latencies of 17 us (and so forth). You should also check the line at the End `# Max Latencies: xxxxx`, which will give you the maximum latency, and the line below which shows you how often the histogram overflowed. > Thanks a lot, > > Regards, > angelo > Hope I could help, Jonathan