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=-5.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS 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 BBAF3C433B4 for ; Mon, 12 Apr 2021 05:35:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8AE6961207 for ; Mon, 12 Apr 2021 05:35:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230255AbhDLFgA (ORCPT ); Mon, 12 Apr 2021 01:36:00 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50312 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230082AbhDLFgA (ORCPT ); Mon, 12 Apr 2021 01:36:00 -0400 Received: from mail-ej1-x631.google.com (mail-ej1-x631.google.com [IPv6:2a00:1450:4864:20::631]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 98368C061574 for ; Sun, 11 Apr 2021 22:35:42 -0700 (PDT) Received: by mail-ej1-x631.google.com with SMTP id a7so18205198eju.1 for ; Sun, 11 Apr 2021 22:35:42 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ionos.com; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=B9whVOjYLNtz/N21mjeKtcvhO5IVOCd2iAu/rBorEB8=; b=doh5Eo4wZ9Hm8tN8np3R/2fkACpxz9WKI+S63Jvg7PZXJs1wWmrFiykiccocODAVJz QXwTKSTYf58zm+5T14iQHu7HQ4STzZBMj1KoRgMYnSwz36rPdXf3Ki9p/mpPX+bc1D0A 6rFG2Uv3gUauw52/2nGHNExJFRFcRWS4G+XiXLhiPeO3QQ1us7LOWfHUzz+3LAW6urez I3LljSkkv1P29vFsDMDbfXeiZ9k8XuhEnquQW6pmTrYZfaI54gFY+TNCUL6z9fRFpLds GJoDlVJDiJgt4wriPbZl2idmx2LobjeQhADpyt96D2W2u+jV6v5K57Zh5g3DIJgw2YtV VRhg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=B9whVOjYLNtz/N21mjeKtcvhO5IVOCd2iAu/rBorEB8=; b=dja82H93TI4uONkiy355OZD4mDoBynB3XVzqM2tqhkavRjLA6x3T/z3TYrgIXZ5Hvo P8P2OUPfogQIDG+KUZPdHxjg5NEhuWoXuLqb2wTN7s7U1cfXb+swx4HBEe8VIx0dlCVw JILpWkfoPfRzwGghPPDXIoCYBT0aSyvw2OGkj4UnP5WfUrH2t3/dzmDPR2GU54UJfxBb r+dxbjE6ilsTNdMUEv50iAy5VMB0tV4U1h5ZdI9triueZRTYtghxHX0L5JdxO2AQyPnQ sJCwFyIraVJXBaq/p2Hq81sI5UqZOrgmmeahsIphBwbB4LXmyz40JHJKA9OH2pdk3afN nZJQ== X-Gm-Message-State: AOAM531jz3oVck10NTxB7m9jvIsQjwMamG9Qp0npD0lspBLGOkJEYQrW J+5QBUDLuM+qOYRNGZZcK1jqKMuRPNnlccebpB2jj4ql090= X-Google-Smtp-Source: ABdhPJyS/CFuvyuLubgivS0yA5o0TCKBtuNYKedcR3zizntArGO261T0PSbh7Q1RdFXR1ffyo8PsP1NzO4EjrIyo4r4= X-Received: by 2002:a17:906:fb81:: with SMTP id lr1mr222748ejb.62.1618205741381; Sun, 11 Apr 2021 22:35:41 -0700 (PDT) MIME-Version: 1.0 References: <20210409160305.711318-1-haris.iqbal@ionos.com> In-Reply-To: From: Jinpu Wang Date: Mon, 12 Apr 2021 07:35:30 +0200 Message-ID: Subject: Re: [PATCH V6 0/3] block: add two statistic tables To: Jens Axboe Cc: Md Haris Iqbal , linux-block , Danil Kipnis Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On Fri, Apr 9, 2021 at 11:03 PM Jens Axboe wrote: > > On 4/9/21 10:03 AM, Md Haris Iqbal wrote: > > Hi Jens, > > > > This version fixes the long lines in the code as per Christoph's comment. > > I'd really like to see some solid justification for the addition, > though. I clicked the v1 link and it's got details on what you get out > of it, but not really the 'why' of reasoning for the feature. I mean, > you could feasibly have a blktrace based userspace solution. Just > wondering if that has been tried, I know that's what we do at Facebook > for example. > Hi Jens, Thanks for the reply. For the use case of the additional stats, as a cloud provider, we often need to handle report from the customers regarding performance problem in a period of time in the past, so it's not feasible for us to run blktrace, customer workload could change from time to time, with the additional stats, we gather through all metrics using Prometheus, we can navigate to the period of time interested, to check if the performance matches the SLA, it also helps us to find the user IO pattern, we can more easily reproduce. We do use blktrace from time to time too if it's not too late (when IO pattern has not changed.) Thanks! Jack