From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756266AbaEGPWp (ORCPT ); Wed, 7 May 2014 11:22:45 -0400 Received: from mx1.redhat.com ([209.132.183.28]:13655 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752238AbaEGPWo (ORCPT ); Wed, 7 May 2014 11:22:44 -0400 Date: Wed, 7 May 2014 11:22:19 -0400 From: Don Zickus To: Namhyung Kim Cc: Arnaldo Carvalho de Melo , Jiri Olsa , Peter Zijlstra , Ingo Molnar , Paul Mackerras , Namhyung Kim , LKML , David Ahern , Andi Kleen Subject: Re: [PATCHSET 00/17] perf report: Add -F option for specifying output fields (v4) Message-ID: <20140507152219.GN39568@redhat.com> References: <87lhuwr2pk.fsf@sejong.aot.lge.com> <20140423125828.GL5328@redhat.com> <1398346899.1681.18.camel@leonhard> <20140424210015.GJ8488@redhat.com> <20140428194642.GQ5328@redhat.com> <878uqpos3k.fsf@sejong.aot.lge.com> <20140429172735.GD32375@redhat.com> <874n1bpuzh.fsf@sejong.aot.lge.com> <20140430133554.GB61249@redhat.com> <87mweunv8p.fsf@sejong.aot.lge.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <87mweunv8p.fsf@sejong.aot.lge.com> 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 Wed, May 07, 2014 at 12:05:58PM +0900, Namhyung Kim wrote: > Hi Don, > > On Wed, 30 Apr 2014 09:35:55 -0400, Don Zickus wrote: > > On Wed, Apr 30, 2014 at 08:38:10AM +0900, Namhyung Kim wrote: > >> Hi Don, > >> > >> On Tue, 29 Apr 2014 13:27:35 -0400, Don Zickus wrote: > >> > On Tue, Apr 29, 2014 at 10:13:35AM +0900, Namhyung Kim wrote: > >> >> > /* > >> >> > * Addresses with no major/minor numbers are assumed to be > >> >> > * anonymous in userspace. Sort those on pid then address. > >> >> > * > >> >> > * The kernel and non-zero major/minor mapped areas are > >> >> > * assumed to be unity mapped. Sort those on address. > >> >> > */ > >> >> > > >> >> > if ((left->cpumode != PERF_RECORD_MISC_KERNEL) && > >> >> > !l_map->maj && !l_map->min && !l_map->ino && > >> >> > !l_map->ino_generation) { > >> >> > /* userspace anonymous */ > >> >> > > >> >> > if (left->thread->pid_ > right->thread->pid_) return -1; > >> >> > if (left->thread->pid_ < right->thread->pid_) return 1; > >> >> > >> >> Isn't it necessary to check whether the address is in a same map in case > >> >> of anon pages? I mean the daddr.al_addr is a map-relative offset so it > >> >> might have same value for different maps. > >> > > >> > That's why I sort on pids here. Because the anon address might have the > >> > same value for different maps. The thought was to group all the pid > >> > addresses together to keep things seperated. > >> > > >> > Do you see a different way to solve the problem? I am not sure al_addr > >> > vs. addr will make much difference here. > >> > >> I'm not saying to get rid of the pid check, I'm saying that it might > >> need to add another check for maps (i.e. start address) as there might > >> be many maps in a single address space. > > > > Hmm, I guess I would need to see an example. While I agree there might be > > many maps in a single address space (/proc//maps demonstrates that), > > I understood them to map to a unique location (ie no overlap) unless they > > are shared. > > > > I am willing to believe I missed scenario when sorting, I just can't think > > of it (so I wouldn't know how to fix it). That's why I was looking for an > > example to make it more obvious to me. Sorry for being slow.. > > I'm also sorry for being late. Looking at the code, it seems to use > identity__map_ip() for anon maps so my concern is bogus. Please just > forget about it and keep going. Sorry for interrupting your work.. No worries. Always good to have an extra pair of eyes. I am a little stuck about where to go. I think it might make sense to submit this as a standalone patch (despite the possible group limitation we are discussing). Thoughts? Cheers, Don