Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934249AbcLMPdy (ORCPT ); Tue, 13 Dec 2016 10:33:54 -0500 Received: from mga07.intel.com ([134.134.136.100]:10125 "EHLO mga07.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933014AbcLMPdr (ORCPT ); Tue, 13 Dec 2016 10:33:47 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.33,342,1477983600"; d="scan'208";a="41874218" From: kan.liang@intel.com To: acme@kernel.org, linux-kernel@vger.kernel.org Cc: dima@secretsauce.net, jolsa@redhat.com, namhyung@kernel.org, andi@firstfloor.org, Kan Liang Subject: [PATCH] perf diff: bug fix, donot overwrite valid build id Date: Tue, 13 Dec 2016 10:29:44 -0500 Message-Id: <1481642984-13593-1-git-send-email-kan.liang@intel.com> X-Mailer: git-send-email 2.4.3 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1939 Lines: 57 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