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=-2.4 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,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 B099FC433E2 for ; Wed, 8 Jul 2020 14:07:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8A21B20720 for ; Wed, 8 Jul 2020 14:07:02 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=cloud.ionos.com header.i=@cloud.ionos.com header.b="foX9E06j" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729653AbgGHOHA (ORCPT ); Wed, 8 Jul 2020 10:07:00 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46810 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729493AbgGHOHA (ORCPT ); Wed, 8 Jul 2020 10:07:00 -0400 Received: from mail-ed1-x542.google.com (mail-ed1-x542.google.com [IPv6:2a00:1450:4864:20::542]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A63E4C061A0B for ; Wed, 8 Jul 2020 07:06:59 -0700 (PDT) Received: by mail-ed1-x542.google.com with SMTP id b15so41917242edy.7 for ; Wed, 08 Jul 2020 07:06:59 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=cloud.ionos.com; s=google; h=subject:from:to:cc:references:message-id:date:user-agent :mime-version:in-reply-to:content-transfer-encoding:content-language; bh=21m5JzfwGq0gXeZrVtL3JyPzgmxD8avEylD2NTGTysA=; b=foX9E06jNMdcDWO81XNGYFn+1KO0b2AnGeu7h3JgmA3r+Ao2tVDX8TrjsGZJfA//FK iPgIKB/Qnh0q7eUJROvb2++9iIPYbltIuajwulED0Qx73mZ4HoVDZh47jNqc4aVcsHjv NzTfMS3t2efc0n6RXdrtRAqzofggqQK5vzoNxkLUo/0CS32537pgnRv7b61Jm8kscYf8 FMpW/pEvh9jY4AIs/KbhMQfe17G6jrA08pQ+1YgwplEAUzLCEoEUGwX8oniRp5uo10WP kO3ekBCnHBGvoR3nm7YkQ/soZKQLi7UIwcEssSew66HyIQ2RH3B+aj19JKhEV/R/FUK1 PegA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:from:to:cc:references:message-id:date :user-agent:mime-version:in-reply-to:content-transfer-encoding :content-language; bh=21m5JzfwGq0gXeZrVtL3JyPzgmxD8avEylD2NTGTysA=; b=XWAndeaBx6L6gKJ3gdgU33va8AiULEZ8uFNrQwzrTUO1BKaJWSwhsTWRzmd7afskDz 2vZomUUUHIMN+FuNZPvgJ1J+EqeQrGqqtjbkIaMMmFJ3Pp6LQdf6WOmoL1UambURizlt eK2hbw15cTLKRjCpwa57cHmWwPdGJ74NKBc8yPz+h4hJraB6fgqtYsOrsfyiWNj8ovaY 8pMO9IaIR1y96rJgcUXnRx1TBmT9yk9w7EUga3SISSQjIDBWTD27zFyNXGs6tWuP06// lQTfwK9lI1PgHMiGzc22qs2oDqwR/5if5CAGMdF2kSb41A0Lo0aBz2ysEc6m49gj1Svz zn1A== X-Gm-Message-State: AOAM530GTvnkv2xHP6u7NcRSJDVs/ZAekSReKZt8LbAqQQgegVPggRp7 +bz2PC6epwDkIOFCca9fTWFPJw== X-Google-Smtp-Source: ABdhPJwUZ5x7pZWbgCfiwR7VNWbDQlirAMs2veqs3gm8NbwH7cQuE/WrpF5nmo/MQlxOwxmM7RDkxg== X-Received: by 2002:a05:6402:b10:: with SMTP id bm16mr20766451edb.92.1594217218402; Wed, 08 Jul 2020 07:06:58 -0700 (PDT) Received: from [192.168.178.33] (i5C746C99.versanet.de. [92.116.108.153]) by smtp.gmail.com with ESMTPSA id z22sm28477085edx.72.2020.07.08.07.06.57 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 08 Jul 2020 07:06:57 -0700 (PDT) Subject: Re: [PATCH RFC 4/5] block: add a statistic table for io latency From: Guoqing Jiang To: Ming Lei Cc: axboe@kernel.dk, linux-block@vger.kernel.org, Florian-Ewald Mueller References: <20200708075819.4531-1-guoqing.jiang@cloud.ionos.com> <20200708075819.4531-5-guoqing.jiang@cloud.ionos.com> <20200708132958.GC3340386@T590> Message-ID: Date: Wed, 8 Jul 2020 16:06:57 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.8.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Content-Language: en-US Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On 7/8/20 4:02 PM, Guoqing Jiang wrote: >> Hi Guoqing, >> >> I believe it isn't hard to write a ebpf based script(bcc or bpftrace) to >> collect this kind of performance data, so looks not necessary to do it >> in kernel. > > Hi Ming, > > Sorry, I don't know well about bcc or bpftrace, but I assume they need to > read the latency value from somewhere inside kernel. Could you point > how can I get the latency value? Thanks in advance! Hmm, I suppose biolatency is suitable for track latency, will look into it. Thanks, Guoqing