From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751866AbeCWOuy (ORCPT ); Fri, 23 Mar 2018 10:50:54 -0400 Received: from mail.kernel.org ([198.145.29.99]:47638 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751658AbeCWOux (ORCPT ); Fri, 23 Mar 2018 10:50:53 -0400 DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5AE842168D Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=acme@kernel.org Date: Fri, 23 Mar 2018 11:50:49 -0300 From: Arnaldo Carvalho de Melo To: "Jin, Yao" Cc: Jiri Olsa , jolsa@kernel.org, peterz@infradead.org, mingo@redhat.com, alexander.shishkin@linux.intel.com, Linux-kernel@vger.kernel.org, ak@linux.intel.com, kan.liang@intel.com, yao.jin@intel.com Subject: Re: [PATCH] perf util: Display warning when perf report/annotate is missing some libs Message-ID: <20180323145049.GF4229@kernel.org> References: <1515668586-14327-1-git-send-email-yao.jin@linux.intel.com> <20180111153028.GB20406@krava> <42a90e87-f2fd-293d-bd25-591fcdff14e1@linux.intel.com> <20180321153807.GA2707@krava> <20180322085147.GI2707@krava> <5f7ae627-572d-fc02-e9ea-ec56b640c636@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <5f7ae627-572d-fc02-e9ea-ec56b640c636@linux.intel.com> X-Url: http://acmel.wordpress.com User-Agent: Mutt/1.9.2 (2017-12-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Em Fri, Mar 23, 2018 at 11:09:03AM +0800, Jin, Yao escreveu: > On 3/22/2018 4:51 PM, Jiri Olsa wrote: > > On Thu, Mar 22, 2018 at 09:04:10AM +0800, Jin, Yao wrote: > > > On 3/21/2018 11:38 PM, Jiri Olsa wrote: > > > > On Wed, Mar 21, 2018 at 10:11:10AM +0800, Jin, Yao wrote: > > > > > Hi Jiri, > > > > > > > > > > I'm still thinking it's worth displaying the warning when perf missing some > > > > > libraries. > > > > > > > > > > Somebody just told me that perf didn't work well. While after some > > > > > investigations, I found it's just missing some libraries when building the > > > > > perf. > > > > > > > > > > But I have spent some time on getting the root cause. If with this patch, it > > > > > should be very easily to know that. > > > > > > > > true.. Arnaldo, any feedback on this one? > > > > > > > > > > I just think it'd better provide some hints to user. For example, > > > > > > "symbol is disabled and you need to install libelf/xxx", say something > > > > > > like that. > > > > > > > > > > > > But it looks the column can't contain too much information (i.e. no more > > > > > > space to contain the entire hints). > > > > > > > > > > > > Any idea? Or just add this warning in verbose mode? > > > > > > > > > > > > > also your change does not affect tui mode > > > > > > > > > > > > > > annotation for some reason does not start at all.. could be > > > > > > > little more verbose ;-) > > > > > > > > > > > > > > jirka > > > > > > > > > > > > > > > > > > > Yes, it doesn't affect tui mode. > > > > > > > > > > > > Or we just add this warning in verbose mode? > > > > > > > > > > > > e.g. perf report -v? > > > > > > > > how about displaying libraries separately with -vv output, > > > > that would mimic the build message, like: > > > > > > > > $ ./perf -vv > > > > perf version 4.16.rc6.g18fd48 > > > > > > > > dwarf: [ on ] > > > > dwarf_getlocations: [ on ] > > > > glibc: [ on ] > > > > gtk2: [ on ] > > > > libaudit: [ on ] > > > > libbfd: [ on ] > > > > libelf: [ on ] > > > > libnuma: [ on ] > > > > numa_num_possible_cpus: [ on ] > > > > libperl: [ on ] > > > > libpython: [ on ] > > > > libslang: [ on ] > > > > libcrypto: [ on ] > > > > libunwind: [ on ] > > > > libdw-dwarf-unwind: [ on ] > > > > zlib: [ on ] > > > > lzma: [ on ] > > > > get_cpuid: [ on ] > > > > bpf: [ on ] > > > > > > > > and perf -vvv could display the 'make VF=1' info > > > > > > > > jirka > > > > > > > > > > I'm just afraid that the newbie will not check the -vv on his own when he > > > gets trouble in using perf. > > > > > > In other words, if a user is experienced and he knows -vv yet, I may assume > > > that he should know installing all libraries before building the perf. > > > > > > This patch is specific for the perf newbie. It will directly shows the > > > error/warning when the user launches the perf binary. It will have a little > > > bit helps, I guess. :) > > > > I just don't like the idea that when you run perf report, > > or annotate it spits out lines for every missing feature > > > > maybe we could detect missing features for given command > > and display line about missing features and say something > > like: > > > > 'Warning: symbol,dwarf support not compiled in (for more details run perf -vv)' > > > > or somwthing like that.. ;-) > > > > jirka > > > > Hi Jiri, > > I think your idea is very good! > > I guess following it's just an example copied from perf building process, > right? > > $ ./perf -vv > perf version 4.16.rc6.g18fd48 > > dwarf: [ on ] > dwarf_getlocations: [ on ] > glibc: [ on ] > gtk2: [ on ] > libaudit: [ on ] > libbfd: [ on ] > libelf: [ on ] > libnuma: [ on ] > numa_num_possible_cpus: [ on ] > libperl: [ on ] > libpython: [ on ] > libslang: [ on ] > libcrypto: [ on ] > libunwind: [ on ] > libdw-dwarf-unwind: [ on ] > zlib: [ on ] > lzma: [ on ] > get_cpuid: [ on ] > bpf: [ on ] > > We can check some CFLAGS like "#ifdef HAVE_XXX" in perf code to determine if > some libraries are compiled in. > > For example, > > #ifdef HAVE_LIBNUMA_SUPPORT > printf("libnuma: [ on ]"); > #endif > > For some features, such as "numa_num_possible_cpus", which doesn't have > CFLAGS variables. Maybe we can ignore them in report? > > I'd like to upgrade my patch to support perf -vv. Please go ahead! :-) We're all on the same page now, I think. - Arnaldo