From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752901AbdKVW76 (ORCPT ); Wed, 22 Nov 2017 17:59:58 -0500 Received: from fldsmtpe03.verizon.com ([140.108.26.142]:12865 "EHLO fldsmtpe03.verizon.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752830AbdKVW02 (ORCPT ); Wed, 22 Nov 2017 17:26:28 -0500 From: alexander.levin@verizon.com Cc: Milian Wolff , David Ahern , Peter Zijlstra , Ravi Bangoria , Yao Jin , Arnaldo Carvalho de Melo , alexander.levin@verizon.com X-Host: surveyor.tdc.vzwcorp.com To: "linux-kernel@vger.kernel.org" , "stable@vger.kernel.org" Subject: [PATCH AUTOSEL for 4.14 18/51] perf callchain: Compare symbol name for inlined frames when matching Thread-Topic: [PATCH AUTOSEL for 4.14 18/51] perf callchain: Compare symbol name for inlined frames when matching Thread-Index: AQHTY+DTfRTdG/7ttEyvGi4onxx0VQ== Date: Wed, 22 Nov 2017 22:25:40 +0000 Message-ID: <20171122222526.20021-18-alexander.levin@verizon.com> References: <20171122222526.20021-1-alexander.levin@verizon.com> In-Reply-To: <20171122222526.20021-1-alexander.levin@verizon.com> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-ms-exchange-messagesentrepresentingtype: 1 x-ms-exchange-transport-fromentityheader: Hosted x-originating-ip: [10.144.60.250] Content-Type: text/plain; charset="iso-8859-1" MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from quoted-printable to 8bit by nfs id vAMN0h0S032306 From: Milian Wolff [ Upstream commit 9856240ad3269f2fdab0b2fa4400ef8aab792061 ] The fake symbols we create for inlined frames will represent different functions but can use the symbol start address. This leads to issues when different inline branches all lead to the same function. Before: ~~~~~ $ perf report -s sym -i perf.inlining.data --inline --stdio -g function ... --38.86%--_start __libc_start_main main | --37.57%--std::norm (inlined) std::_Norm_helper::_S_do_it (inlined) | --36.36%--std::abs (inlined) std::__complex_abs (inlined) | --12.24%--std::linear_congruential_engine::operator() (inlined) std::__detail::__mod (inlined) std::__detail::_Mod::__calc (inlined) ~~~~~ Note that this backtrace representation is completely bogus. Complex abs does not call the linear congruential engine! It is just a side-effect of a longer inlined stack being appended to a shorter, different inlined stack, both of which originate in the same function (main). This patch fixes the issue: ~~~~~ $ perf report -s sym -i perf.inlining.data --inline --stdio -g function ... --38.86%--_start __libc_start_main main | |--35.59%--std::uniform_real_distribution::operator() > (inlined) | std::uniform_real_distribution::operator() > (inlined) | | | --34.37%--std::__detail::_Adaptor, double>::operator() (inlined) | std::generate_canonical > (inlined) | | | --12.24%--std::linear_congruential_engine::operator() (inlined) | std::__detail::__mod (inlined) | std::__detail::_Mod::__calc (inlined) | --1.99%--std::norm (inlined) std::_Norm_helper::_S_do_it (inlined) std::abs (inlined) std::__complex_abs (inlined) ~~~~~ Signed-off-by: Milian Wolff Reviewed-by: Jiri Olsa Reviewed-by: Namhyung Kim Cc: David Ahern Cc: Peter Zijlstra Cc: Ravi Bangoria Cc: Yao Jin Link: http://lkml.kernel.org/r/20171009203310.17362-10-milian.wolff@kdab.com Cc: Arnaldo Carvalho de Melo [ Fix up conflict with c1fbc0cf81f1 ("perf callchain: Compare dsos (as well) for CCKEY_FUNCTION"), remove unneeded hunk ] Signed-off-by: Arnaldo Carvalho de Melo Signed-off-by: Sasha Levin --- tools/perf/util/callchain.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/tools/perf/util/callchain.c b/tools/perf/util/callchain.c index 6031933d811c..3cc51e852cf0 100644 --- a/tools/perf/util/callchain.c +++ b/tools/perf/util/callchain.c @@ -697,6 +697,14 @@ static enum match_result match_chain(struct callchain_cursor_node *node, } if (cnode->ms.sym && sym && callchain_param.key == CCKEY_FUNCTION) { + /* + * Compare inlined frames based on their symbol name because + * different inlined frames will have the same symbol start + */ + if (cnode->ms.sym->inlined || node->sym->inlined) + return match_chain_strings(cnode->ms.sym->name, + node->sym->name); + left = cnode->ms.sym->start; right = sym->start; left_dso = cnode->ms.map->dso; -- 2.11.0