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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8830BC433F5 for ; Wed, 1 Dec 2021 00:37:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1345833AbhLAAkX (ORCPT ); Tue, 30 Nov 2021 19:40:23 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55430 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1345797AbhLAAkV (ORCPT ); Tue, 30 Nov 2021 19:40:21 -0500 Received: from mail-io1-xd31.google.com (mail-io1-xd31.google.com [IPv6:2607:f8b0:4864:20::d31]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5563AC061574 for ; Tue, 30 Nov 2021 16:37:01 -0800 (PST) Received: by mail-io1-xd31.google.com with SMTP id x6so28342884iol.13 for ; Tue, 30 Nov 2021 16:37:01 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=6KT7YyaxqjVs5mSuQwjMampQZClAeRv4K4OAPJNJd20=; b=ZSeoFG71k5erKk/MKPfg36Ze35fwc7Cua8svHc9JAorrJC+frFECdyJzDHIzZKGRce wYUG3w6YTmcSVnoOmf3s5zPBgrqTHph+DcndRt3PAClRXL+NnbMT+bW9nd8VwWkMWH8U aGhALR3nY0eGcGQCmuuxO199U29F0+oFV8xSwDq55/+z17KERuy3l7FSBdhZ+mbqpw9A isN+7VlTAQf9JRT63HkP7fcl4h1A07jZ2jhFy6V0+j3olZkT8vpL9Vk8LNKylPHf6+FJ x6da5lqrPnBq16RL+m1Ig0BVHuCWFgMJhsON6MtHwUM/x1mKWbLAaBOELMGr1hYQML5h eUpg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=6KT7YyaxqjVs5mSuQwjMampQZClAeRv4K4OAPJNJd20=; b=hmVoGkQfiKetCOPUHjElGJRwjDwWSHYdwiWZGd7OsXPqIRfFiSCUQAp0+zESJOySfv S6MfyBIBZcM6/qSauHzcCqQEpgN7eGM83MRocYU/I7z5pEkX/p/5PuxzisKBjWaiBVoe 2PnV6jjYFU+RcQGY6wcQLuxMxD6UTsxbkigmpzNRn6W7HZckXvAHZQr+5a76ImjuE7zA TYV8jUZVF+csnFZCZkEG43AUXAu/cDtFoGdI09ePndeq7M9XLbbN3NLO0ymdNhXcjSDj GCD2xwfyfnxC7Berci3HVLvjFzPqiaP32HXI0keDGjI15wFzzzHrszUtZnEr5Vxj6nVO ghIQ== X-Gm-Message-State: AOAM5310K9d0hjMmrVUAxCmFY5gEACJMuZLXOOChfDTNQyy7Pz9Dpm8G ZjiVtmiGzf0J5QZkbkfIih0iavgt8ptlpBhP4wBM4w== X-Google-Smtp-Source: ABdhPJxEWWGRI9CkNjtOLdkRHCbCAy0RCyi3Yn1qBz5cJ/XJJEFadsnDmkChbvW9Dh+395dbt1IVilO9VUKyXyTDpTo= X-Received: by 2002:a5d:9492:: with SMTP id v18mr3969213ioj.158.1638319020517; Tue, 30 Nov 2021 16:37:00 -0800 (PST) MIME-Version: 1.0 References: <20211129231830.1117781-1-namhyung@kernel.org> In-Reply-To: From: Stephane Eranian Date: Tue, 30 Nov 2021 16:36:49 -0800 Message-ID: Subject: Re: [RFC/PATCHSET 0/5] perf ftrace: Implement function latency histogram (v1) To: Namhyung Kim Cc: Arnaldo Carvalho de Melo , Jiri Olsa , Ingo Molnar , Peter Zijlstra , LKML , Andi Kleen , Ian Rogers , Song Liu , Changbin Du Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Nov 30, 2021 at 2:58 PM Namhyung Kim wrote: > > Hi Arnaldo, > > On Tue, Nov 30, 2021 at 6:37 AM Arnaldo Carvalho de Melo > wrote: > > > > Em Mon, Nov 29, 2021 at 03:18:25PM -0800, Namhyung Kim escreveu: > > > Hello, > > > > > > I've implemented 'latency' subcommand in the perf ftrace command to > > > show a histogram of function latency. > > > > > > To handle new subcommands, the existing functionality is moved to > > > 'trace' subcommand while preserving backward compatibility of not > > > having a subcommand at all (defaults to 'trace'). > > > > > > The latency subcommand accepts a target (kernel, for now) function > > > with -T option and shows a histogram like below: > > > > Humm, wouldn't be interesting to shorten this by having a new 'perf > > flat' (function latency) tool, on the same level as 'perf ftrace' and > > leave 'perf ftrace' to just being a convenient perf interface to what > > ftrace provides? > > That would be fine. I also think 'perf ftrace latency' is > bit too long. But if we would add a new feature > like argdist (in BCC) later, I thought it'd be nice being > a subcommand in the perf ftrace together. > > But it's up to you. I'll make a change if you prefer > 'flat' (or how about 'fnlat' instead?). > I am not too fond of the flat option because as we had more bpf tools like function latency, then we keep extending the list of commands each with a small span which is different from what we have right now.