From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8566BC282DD for ; Wed, 8 Jan 2020 13:02:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 607E920643 for ; Wed, 8 Jan 2020 13:02:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727411AbgAHNCH (ORCPT ); Wed, 8 Jan 2020 08:02:07 -0500 Received: from mga03.intel.com ([134.134.136.65]:16900 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726144AbgAHNCH (ORCPT ); Wed, 8 Jan 2020 08:02:07 -0500 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga007.jf.intel.com ([10.7.209.58]) by orsmga103.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 08 Jan 2020 05:02:06 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.69,410,1571727600"; d="scan'208";a="211528356" Received: from yjin15-mobl.ccr.corp.intel.com (HELO [10.254.213.183]) ([10.254.213.183]) by orsmga007.jf.intel.com with ESMTP; 08 Jan 2020 05:02:03 -0800 Subject: Re: [PATCH] perf report: Fix no libunwind compiled warning break s390 issue 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, tmricht@linux.ibm.com References: <20200107191745.18415-1-yao.jin@linux.intel.com> <20200108102708.GC360164@krava> From: "Jin, Yao" Message-ID: <7b88fdcc-9603-d3e1-d43b-b8fb8b394f70@linux.intel.com> Date: Wed, 8 Jan 2020 21:02:02 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:60.0) Gecko/20100101 Thunderbird/60.9.1 MIME-Version: 1.0 In-Reply-To: <20200108102708.GC360164@krava> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 1/8/2020 6:27 PM, Jiri Olsa wrote: > On Wed, Jan 08, 2020 at 03:17:45AM +0800, Jin Yao wrote: >> Commit 800d3f561659 ("perf report: Add warning when libunwind not compiled in") >> breaks the s390 platform. S390 uses libdw-dwarf-unwind for call chain >> unwinding and had no support for libunwind. >> >> So the warning "Please install libunwind development packages during the perf build." >> caused the confusion even if the call-graph is displayed correctly. >> >> This patch adds checking for HAVE_DWARF_SUPPORT, which is set when >> libdw-dwarf-unwind is compiled in. >> >> Fixes: 800d3f561659 ("perf report: Add warning when libunwind not compiled in") >> >> Reviewed-by: Thomas Richter >> Tested-by: Thomas Richter >> Signed-off-by: Jin Yao > > perfect, I have the same change prepared for sending, but it's > together with making libdw default dwarf unwinder, which I'm still > not sure we want to do, so it all got posponed ;-) > > would you guys be ok with that? with having libdw picked up as default dwarf unwinder.. > I've roughly compared the performance between libunwind-dev and libdw-dev. While in my test (on KBL desktop), for the same perf report command-line, it looks the perf built with libunwind-dev is much faster than the perf built with libdw-dev. The command line is as following: perf record --call-graph dwarf ./div perf report -g graph --stdio Maybe you give it a try. :) > for the patch: > > Acked-by: Jiri Olsa > Thanks for reviewing the patch. Thanks Jin Yao > thanks, > jirka > >> --- >> tools/perf/builtin-report.c | 6 +++--- >> 1 file changed, 3 insertions(+), 3 deletions(-) >> >> diff --git a/tools/perf/builtin-report.c b/tools/perf/builtin-report.c >> index de988589d99b..66cd97cc8b92 100644 >> --- a/tools/perf/builtin-report.c >> +++ b/tools/perf/builtin-report.c >> @@ -412,10 +412,10 @@ static int report__setup_sample_type(struct report *rep) >> PERF_SAMPLE_BRANCH_ANY)) >> rep->nonany_branch_mode = true; >> >> -#ifndef HAVE_LIBUNWIND_SUPPORT >> +#if !defined(HAVE_LIBUNWIND_SUPPORT) && !defined(HAVE_DWARF_SUPPORT) >> if (dwarf_callchain_users) { >> - ui__warning("Please install libunwind development packages " >> - "during the perf build.\n"); >> + ui__warning("Please install libunwind or libdw " >> + "development packages during the perf build.\n"); >> } >> #endif >> >> -- >> 2.17.1 >> >