Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752296AbbLNOzh (ORCPT ); Mon, 14 Dec 2015 09:55:37 -0500 Received: from mail-oi0-f51.google.com ([209.85.218.51]:33389 "EHLO mail-oi0-f51.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751334AbbLNOzg (ORCPT ); Mon, 14 Dec 2015 09:55:36 -0500 Subject: Re: [PATCHSET 00/16] perf top: Add multi-thread support (v1) To: Ingo Molnar , Peter Zijlstra References: <1449734015-9148-1-git-send-email-namhyung@kernel.org> <20151210080118.GA8664@gmail.com> <5E6F0F13-9696-45F1-A0E8-CA0B95020D10@gmail.com> <20151211081141.GA21600@gmail.com> <566AE54B.1010702@gmail.com> <20151214092613.GL6357@twins.programming.kicks-ass.net> <20151214093841.GB30347@gmail.com> Cc: Namhyung Kim , Namhyung Kim , Arnaldo Carvalho de Melo , Jiri Olsa , LKML , Frederic Weisbecker , Andi Kleen , Stephane Eranian , Adrian Hunter From: David Ahern Message-ID: <566ED864.1040500@gmail.com> Date: Mon, 14 Dec 2015 07:55:32 -0700 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.11; rv:38.0) Gecko/20100101 Thunderbird/38.4.0 MIME-Version: 1.0 In-Reply-To: <20151214093841.GB30347@gmail.com> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2290 Lines: 60 On 12/14/15 2:38 AM, Ingo Molnar wrote: > >> And in an unrelated note, I absolutely detest --buildid being the >> default, it makes perf-record blow chunks. Yes, a .debug directory that gets bloated fast and being a dot-directory is off the primary radar. I forget about it and too often forget to add the option to disable it. > > So I'd absolutely _love_ to split up the singular perf.data into a hierarchy of > files in a .perf directory, with a structure like this (4-core system): > > .perf/cmdline > .perf/features > .perf/evlist > .perf/ring_buffers/cpu0/raw.trace > .perf/ring_buffers/cpu1/raw.trace > .perf/ring_buffers/cpu2/raw.trace > .perf/ring_buffers/cpu3/raw.trace > ... On a related note why a .perf directory? > > I.e. the current single file format of perf.data would be split up into individual > files. Each CPU would get its own trace file output - any sorting and ordering > would be done afterwards. 'perf record' itself would never by default have to do > any of that, it's a pure recording session. > > 'perf archive' would still create a single file to make transport between machines > easy. > > perf.data.old would be replaced by a .perf.old directory or so. > > Debugging would be easier too I think, as there's no complex perf data format > anymore, it's all in individual (typically text, or binary dump) files in the > .perf directory. > > This would solve all the scalability problems - and would make the format more > extensible and generally more accessible as well. > > What do you think? Big change to user experience. I realize perf-archive has been around since I started using perf in mid-2010, but I for one never use it. I suspect it is not widely used (definitely not in the circles I have been involved and helped with perf), so suddenly requiring it is a change in user experience. The only 2 files on the system I pull off the box are kallsyms and perf.data. Most of the systems where I use perf have limited symbols and there is nothing in .debug I need to pull of the box. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/