From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752403Ab3IIOEY (ORCPT ); Mon, 9 Sep 2013 10:04:24 -0400 Received: from mx1.redhat.com ([209.132.183.28]:45685 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751221Ab3IIOEW (ORCPT ); Mon, 9 Sep 2013 10:04:22 -0400 Date: Mon, 9 Sep 2013 16:03:39 +0200 From: Jiri Olsa To: Peter Zijlstra Cc: linux-kernel@vger.kernel.org, Corey Ashford , Frederic Weisbecker , Ingo Molnar , Namhyung Kim , Paul Mackerras , Arnaldo Carvalho de Melo , Andi Kleen , David Ahern Subject: Re: [PATCHv2 00/25] perf tool: Add support for multiple data file storage Message-ID: <20130909140339.GB16401@krava.redhat.com> References: <1378031796-17892-1-git-send-email-jolsa@redhat.com> <20130909111749.GP31370@twins.programming.kicks-ass.net> <20130909113640.GA16401@krava.redhat.com> <20130909115518.GA26785@twins.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20130909115518.GA26785@twins.programming.kicks-ass.net> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Sep 09, 2013 at 01:55:18PM +0200, Peter Zijlstra wrote: > On Mon, Sep 09, 2013 at 01:36:41PM +0200, Jiri Olsa wrote: > > On Mon, Sep 09, 2013 at 01:17:49PM +0200, Peter Zijlstra wrote: > > > On Sun, Sep 01, 2013 at 12:36:11PM +0200, Jiri Olsa wrote: > > This patchset is actually doing 3 essential things: > > 1) adds new perf data format version (v3) > > 2) adds class/object to handle perf data file > > 3) adds record '-M size' option > > So the -M thing is where the multiple files stuff comes from, right? > What's the purpose of this? Why would I care how big these files get, > surely filesystems handle 4g+ files these days. my usage currently is to having this running during the day: (well whenever I remember to run it.. ;-) ) [jolsa@krava perf]$ sudo ./perf record -g -M 1m -a and checking report when the system or app get stuck with multiple files I can just easily (or automaticaly) remove old ones without restarting session > > > > The only reason I wanted this is so that each thread can write its own > > > data. The current one file thing is an immense bottle-neck for big > > > machines. > > > > > > > I haven't considered the thread based storage yet, but I > > think having the simplified format and centralized file > > handling will only help. > > Please do consider it now, it'd suck to have to change the file format > thing yet again. ook > > With both per-thread and size limited your filename generation needs > some extra bits I suppose. yep, and probably some merging at the end jirka