From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753612AbaHKNcb (ORCPT ); Mon, 11 Aug 2014 09:32:31 -0400 Received: from mail.kernel.org ([198.145.19.201]:55589 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753441AbaHKNc3 (ORCPT ); Mon, 11 Aug 2014 09:32:29 -0400 Date: Mon, 11 Aug 2014 10:32:23 -0300 From: Arnaldo Carvalho de Melo To: Namhyung Kim Cc: Peter Zijlstra , Ingo Molnar , Paul Mackerras , Namhyung Kim , LKML , Jiri Olsa Subject: Re: [PATCH 8/8] perf symbol: Don't demangle parameters and such by default Message-ID: <20140811133223.GC3277@kernel.org> References: <1406785662-5534-1-git-send-email-namhyung@kernel.org> <1406785662-5534-9-git-send-email-namhyung@kernel.org> <20140802133503.GE13375@kernel.org> <87mwbbfnj2.fsf@sejong.aot.lge.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <87mwbbfnj2.fsf@sejong.aot.lge.com> X-Url: http://acmel.wordpress.com User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Em Mon, Aug 11, 2014 at 05:17:37PM +0900, Namhyung Kim escreveu: > On Sat, 2 Aug 2014 10:35:03 -0300, Arnaldo Carvalho de Melo wrote: > > Em Thu, Jul 31, 2014 at 02:47:42PM +0900, Namhyung Kim escreveu: > >> Some C++ symbols have very long name and they make column length > >> longer. Most of them are about parameters including templates and we > >> can ignore such info most of time IMHO. > >> This patch passes DMGL_NO_OPTS by default when calling bfd_demangle(). > >> One can still see full symbols with -v/--verbose option. > >> before: > >> JS_CallFunctionValue(JSContext*, JSObject*, JS::Value, unsigned int, JS::Value*, JS::Value*) > >> after: > >> JS_CallFunctionValue > > Are you sure we want that? > > With this we'll end up having different instantiations having the same > > name, since the way to differentiate them is exactly by a different > > parameter list, no? > > Right, but I think it's not a big problem since such overloaded > functions will not be shown at the same time as only one of them might > do the real work most cases. Simply noticing one of them is a But then only someone that has deep knowledge of the code in question will figure that out from just the function name. A way to toggle that, starting with a sane value, in this case probably not showing the parameter listing due to it being overly long would be ideal. Perhaps I can process this patch now and leave this toggling of things that --verbose shows to a second patchset, where this and --show-total-period, --show-nr-samples, --hide-unresolved, even annotation stuff needs to be on-the-fly togglable, like --disassembly-style. > performance bottle neck would be helpful to the developer, I guess. > Even if it's not the case, one still can see and identify the correct > one using the -v option. > For me, it's just annoying when (unimportant) C++ symbols occupy too > much space in a limited terminal width. What is annoying/unimportant to a person may be the missing detail for someone else. Not having to restart a possibly long top/report session from scratch looks like a nice feature to have. I'll take the patch, its just one more thing that gets in the --verbose grab bag till we make all on-the-fly togglable. - Arnaldo