From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751630AbeCUCLO (ORCPT ); Tue, 20 Mar 2018 22:11:14 -0400 Received: from mga01.intel.com ([192.55.52.88]:18994 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751448AbeCUCLM (ORCPT ); Tue, 20 Mar 2018 22:11:12 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.48,338,1517904000"; d="scan'208";a="29820779" Subject: Re: [PATCH] perf util: Display warning when perf report/annotate is missing some libs From: "Jin, Yao" To: Jiri Olsa Cc: acme@kernel.org, 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 References: <1515668586-14327-1-git-send-email-yao.jin@linux.intel.com> <20180111153028.GB20406@krava> Message-ID: <42a90e87-f2fd-293d-bd25-591fcdff14e1@linux.intel.com> Date: Wed, 21 Mar 2018 10:11:10 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:52.0) Gecko/20100101 Thunderbird/52.6.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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. Thanks Jin Yao On 1/12/2018 10:22 AM, Jin, Yao wrote: > > > On 1/11/2018 11:30 PM, Jiri Olsa wrote: >> On Thu, Jan 11, 2018 at 07:03:06PM +0800, Jin Yao wrote: >>> We keep having bug reports that when users build perf on their own, >> >> we already have same warnings during the build >> > > Yes, there will be warnings displayed during the build if some libraries > are missing. > > While I do find the users (especially the new perf user) don't notice > the warning. They only care about the success of build. > > Once they use this perf version and find something working strangely, > they will say that perf may have bug. :( > >>> but they don't install some needed libraries like libelf, >>> libbfd/libibery. >> >> how about saying that in the symbol column, >> instead of poluting report's output, like: >> >>     $ perf report --stdio >> >>     # Overhead  Command  Shared Object     Symbol (disabled) >>     # ........  .......  ................  ...................... >> > > 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? > > Thanks > Jin Yao