Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933612AbcLSSiF (ORCPT ); Mon, 19 Dec 2016 13:38:05 -0500 Received: from mail.kernel.org ([198.145.29.136]:48978 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932619AbcLSSiF (ORCPT ); Mon, 19 Dec 2016 13:38:05 -0500 Date: Mon, 19 Dec 2016 15:37:58 -0300 From: "acme@kernel.org" To: "Liang, Kan" Cc: "linux-kernel@vger.kernel.org" , "dima@secretsauce.net" , "jolsa@redhat.com" , "namhyung@kernel.org" , "andi@firstfloor.org" Subject: Re: [PATCH] perf diff: bug fix, donot overwrite valid build id Message-ID: <20161219183758.GC551@kernel.org> References: <1481642984-13593-1-git-send-email-kan.liang@intel.com> <37D7C6CF3E00A74B8858931C1DB2F07753682E46@SHSMSX103.ccr.corp.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <37D7C6CF3E00A74B8858931C1DB2F07753682E46@SHSMSX103.ccr.corp.intel.com> X-Url: http://acmel.wordpress.com User-Agent: Mutt/1.7.1 (2016-10-04) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2343 Lines: 70 Em Mon, Dec 19, 2016 at 02:53:30PM +0000, Liang, Kan escreveu: > Hi Arnaldo, > > Ping > > Are you OK with the fix? Yeah, looks ok, will merge it. - Arnaldo > Thanks, > Kan > > > > > From: Kan Liang > > > > Fixes a perf diff regression issue which was introduced by commit > > 5baecbcd9c9a ("perf symbols: we can now read separate debug-info files > > based on a build ID") > > > > The binary name could be same when perf diff different binaries. Build id is > > used to distinguish between them. > > However, the previous patch assumes the same binary name has same > > build id. So it overwrites the build id according to the binary name, > > regardless of whether the build id is set or not. > > > > Check the has_build_id in dso__load. If the build id is already set, use it. > > > > Before the fix applies, > > sudo ./perf diff 1.perf.data 2.perf.data # Event 'cycles' > > # > > # Baseline Delta Shared Object Symbol > > # ........ ....... ................ ............................. > > # > > 99.83% -99.80% tchain_edit [.] f2 > > 0.12% +99.81% tchain_edit [.] f3 > > 0.02% -0.01% [ixgbe] [k] ixgbe_read_reg > > > > After the fix applies, > > sudo ./perf diff 1.perf.data 2.perf.data # Event 'cycles' > > # > > # Baseline Delta Shared Object Symbol > > # ........ ....... ................ ............................. > > # > > 99.83% +0.10% tchain_edit [.] f3 > > 0.12% -0.08% tchain_edit [.] f2 > > > > Signed-off-by: Kan Liang > > --- > > tools/perf/util/symbol.c | 3 ++- > > 1 file changed, 2 insertions(+), 1 deletion(-) > > > > diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c index > > df2482b..dc93940 100644 > > --- a/tools/perf/util/symbol.c > > +++ b/tools/perf/util/symbol.c > > @@ -1459,7 +1459,8 @@ int dso__load(struct dso *dso, struct map *map) > > * Read the build id if possible. This is required for > > * DSO_BINARY_TYPE__BUILDID_DEBUGINFO to work > > */ > > - if (is_regular_file(dso->long_name) && > > + if (!dso->has_build_id && > > + is_regular_file(dso->long_name) && > > filename__read_build_id(dso->long_name, build_id, > > BUILD_ID_SIZE) > 0) > > dso__set_build_id(dso, build_id); > > > > -- > > 2.4.3