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,URIBL_BLOCKED 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 AF0EBC433ED for ; Mon, 19 Apr 2021 06:37:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7BC2061104 for ; Mon, 19 Apr 2021 06:37:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229652AbhDSGiY (ORCPT ); Mon, 19 Apr 2021 02:38:24 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54526 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229630AbhDSGiY (ORCPT ); Mon, 19 Apr 2021 02:38:24 -0400 Received: from mail-ej1-x629.google.com (mail-ej1-x629.google.com [IPv6:2a00:1450:4864:20::629]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 06F66C06174A for ; Sun, 18 Apr 2021 23:37:55 -0700 (PDT) Received: by mail-ej1-x629.google.com with SMTP id n2so51086202ejy.7 for ; Sun, 18 Apr 2021 23:37:54 -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=5PDXy/9Y/FcTdSRegonFGq/cV3kr8MsnTdhmYheEH7w=; b=iZKKZqWXEwEJYuyS4GVwN97yAB9OMoCAKiyRWtMFiHPEj97aL44E14HjxSUYRec82t ueRfvDAPQeh20LZ3dn6o76QajV+8jCxbtrslt8IQAHhfr5yxCO8+JDFthvx9gynSZbMf enERyJ4MfDCTaVhoLtrHKLawLixVdDi+6J7/Zn3qYjIOA3hxM2acwenCChuw9rGexHF4 3b0oBqdWJDpDmXC4fi5VfhEIP4jNizLqkbntjmc+zTlDU5I271IN3sOiETyKTXosj/Y+ GYr0OJoiexP5Y/KMWkxqBKpeughCNURsnCScsYAcZ9pjYgtx6EsqSyDCSMiUDRpYG96c 34rw== 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=5PDXy/9Y/FcTdSRegonFGq/cV3kr8MsnTdhmYheEH7w=; b=aOAypXaO1ABiy+UhYkiVBrzkvxMiAmVJjxPEl+Z0boCqYXzH89v6qK2Q7rr3JERUT8 jBVWJ2BftNFlZh6wJ7U70IsWNEMJb2UuFnj18h84m63o+iU5udVwGACgI2jd2m/luGNk tURhSr0Hg/OKKQahh7dhpJo+heBZgt9HLbyCzSkhqRLEQf7J/nv7rSCxg5pyJnCdJH8y 7cE1fso5eGF2rzj8pt3jYlhkTYfZIQuyOlLzGiJ3p/V1Tr3+CxDz2qhU+KTJyZpfTheJ /Juo9WSQeIo+5n53Y44pkPfq4MjaIV4EZz78/AObcP3qturkgzrl5dwWUAnP6k0Tvfjk wkSw== X-Gm-Message-State: AOAM531rAXrfh8VqKlSJDyKOXqPKP90Gb++mOygeceewukzlYXzw33NW Xaw4SLHSbYe2Dv4JMRKRpSby6YOLfvsnT0SAhP0p7g== X-Google-Smtp-Source: ABdhPJyFH5TiK2kctLROT48iODF2bpqb94Bq8jbtU4QpWvrK7vjeNdfOSTNSqOZ0SP9cL44itLvVgRPHmJBCFP9ivgM= X-Received: by 2002:a17:906:fca1:: with SMTP id qw1mr20094855ejb.478.1618814273733; Sun, 18 Apr 2021 23:37:53 -0700 (PDT) MIME-Version: 1.0 References: <20210409160305.711318-1-haris.iqbal@ionos.com> In-Reply-To: From: Jinpu Wang Date: Mon, 19 Apr 2021 08:37:43 +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 Mon, Apr 12, 2021 at 7:35 AM Jinpu Wang wrote: > > 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 Hi Jens, A gentle ping!