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=-2.3 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,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 2D2EEC41621 for ; Tue, 24 Mar 2020 16:06:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 04EC020788 for ; Tue, 24 Mar 2020 16:06:33 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=kernel-dk.20150623.gappssmtp.com header.i=@kernel-dk.20150623.gappssmtp.com header.b="fQEuKNFQ" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728312AbgCXQGc (ORCPT ); Tue, 24 Mar 2020 12:06:32 -0400 Received: from mail-io1-f65.google.com ([209.85.166.65]:35757 "EHLO mail-io1-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727730AbgCXQGb (ORCPT ); Tue, 24 Mar 2020 12:06:31 -0400 Received: by mail-io1-f65.google.com with SMTP id h8so18664638iob.2 for ; Tue, 24 Mar 2020 09:06:29 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.20150623.gappssmtp.com; s=20150623; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=ojwoexmi/yNDp0QrqjuP+tb9z9BxusbHoCk6iHU7shU=; b=fQEuKNFQnAsD07TtSc6hXHFzVHp8dLZVMVM5iWSjjjdGw4f2R/gciWR/viQuDDtOfX 7es7jXjtssrvriqGFL5nVHrdtsxIQvYC/VBWTu7PB5BmEH27FnpoqZIsDCbsw97eSlDY Ypij/2VgnN453qPo4pw07Ld9eSes/EugM5d7Zk1sVvuNNZpJjGUisbNxO7GgHret37KC 1CfI/hbxhhzJAM+DO6H/4zytEk592jhdyJRt60sxjsWFwAAXXXdz90/LvucNkwXawTqM mF98FzSQfTQqxNOi/Mh0yyw26lXdwssdBTUc9eu4RLefyEvSv7XrpcCxtBeW+okQsfPq UC9g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=ojwoexmi/yNDp0QrqjuP+tb9z9BxusbHoCk6iHU7shU=; b=iB1V5lSRDaFO30DY86RQ//5lhtlcFq5Db6U7dVPB3qZc47b8fzSWhNVdJLJUQV4FMX UayO1LUMPXAmPXej5grFDPVKJFdtyqAh5FCL3hPX1BaP83iO8PkhjNYAGa6bgmZ+7k8g 4BJ432GnS+9VuEB0cUm3uIHpv9LCJT27gidC/NtL2VVlvR/IRLpHAoB/Zw6a2rAjp2hQ WcMMzOH7U1ar/USC8uH5HaM3mY2grHBVt3+y886r4ZxCcJQQDVs7NI7nzADxHx48irlP Til/KOIhpnlSrD/7qlZ/iX8cpGfo0DRxw7ho0XcnOYeneTqnQw1wSVH7cC6ARbyeNisb 9DgQ== X-Gm-Message-State: ANhLgQ3rSO6HeWcoAoVB3Hb+udguG4m7X+plc+6NK+fSJXwvorCoxmGd fwSTY+Z76FwVCyfvEODevSeQkg== X-Google-Smtp-Source: ADFU+vtSEIy6OU2P3p0F5VYmIIPCNs10wRnCB6nYzCevCk/nSG4XkYeAO/0NiEIbndZmWaAyWKV5KQ== X-Received: by 2002:a6b:156:: with SMTP id 83mr24819257iob.187.1585065989365; Tue, 24 Mar 2020 09:06:29 -0700 (PDT) Received: from [192.168.1.159] ([65.144.74.34]) by smtp.gmail.com with ESMTPSA id n18sm6464554ilq.38.2020.03.24.09.06.28 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 24 Mar 2020 09:06:28 -0700 (PDT) Subject: Re: [PATCH v3 0/3] block/diskstats: more accurate io_ticks and optimization To: Konstantin Khlebnikov , linux-block@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Mikulas Patocka , Mike Snitzer , Ming Lei References: <158503038812.1955.7827988255138056389.stgit@buzz> From: Jens Axboe Message-ID: <8aa3e8f7-cd53-b038-d5a7-dca7bf3fa929@kernel.dk> Date: Tue, 24 Mar 2020 10:06:26 -0600 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.4.1 MIME-Version: 1.0 In-Reply-To: <158503038812.1955.7827988255138056389.stgit@buzz> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 3/24/20 12:39 AM, Konstantin Khlebnikov wrote: > Simplified estimation for io_ticks introduced in patch > https://lore.kernel.org/linux-block/20181206164122.2166-5-snitzer@redhat.com/ > could be very inaccurate for request longer than jiffy (i.e. any HDD) > > There is at least one another report about this: > https://lore.kernel.org/linux-block/20200324031942.GA3060@ming.t460p/ > See detail in comment for first patch. > > v1: https://lore.kernel.org/lkml/155413438394.3201.15211440151043943989.stgit@buzz/ > v2: https://lore.kernel.org/lkml/158314549775.1788.6529015932237292177.stgit@buzz/ > v3: > * update documentation > * rebase to current linux-next > * fix compilation for CONFIG_SMP=n Can you respin this against my for-5.7/block branch? -- Jens Axboe