Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752586AbbLJT0a (ORCPT ); Thu, 10 Dec 2015 14:26:30 -0500 Received: from mail.kernel.org ([198.145.29.136]:46298 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752422AbbLJT02 (ORCPT ); Thu, 10 Dec 2015 14:26:28 -0500 Date: Thu, 10 Dec 2015 16:26:19 -0300 From: "'Arnaldo Carvalho de Melo'" To: =?utf-8?B?5bmz5p2+6ZuF5bezIC8gSElSQU1BVFXvvIxNQVNBTUk=?= Cc: Peter Zijlstra , Adrian Hunter , "linux-kernel@vger.kernel.org" , "linux-perf-users@vger.kernel.org" , Ingo Molnar , Namhyung Kim , Jiri Olsa Subject: Re: [PATCH perf/core 14/22] perf: Fix dso__load_sym to put dso Message-ID: <20151210192619.GK17996@kernel.org> References: <20151209021047.10245.8918.stgit@localhost.localdomain> <20151209021118.10245.49869.stgit@localhost.localdomain> <20151209141601.GE15864@kernel.org> <50399556C9727B4D88A595C8584AAB375264F788@GSjpTKYDCembx32.service.hitachi.net> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <50399556C9727B4D88A595C8584AAB375264F788@GSjpTKYDCembx32.service.hitachi.net> X-Url: http://acmel.wordpress.com User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2166 Lines: 51 Em Thu, Dec 10, 2015 at 08:52:46AM +0000, 平松雅巳 / HIRAMATU，MASAMI escreveu: > From: Arnaldo Carvalho de Melo [mailto:acme@kernel.org] > > > >Em Wed, Dec 09, 2015 at 11:11:18AM +0900, Masami Hiramatsu escreveu: > >> +++ b/tools/perf/util/symbol-elf.c > >> @@ -1045,6 +1045,8 @@ int dso__load_sym(struct dso *dso, struct map *map, > >> /* kmaps already got it */ > >> map__put(curr_map); > >> dsos__add(&map->groups->machine->dsos, curr_dso); > >> + /* curr_map and machine->dsos already got it */ > >> + dso__put(curr_dso); > >> dso__set_loaded(curr_dso, map->type); > >> } else > >> curr_dso = curr_map->dso; > > > >Right, to make the code smaller, how about doing it this way, i.e. drop > >the reference once we have that curr_dso object with a ref held by > >curr_map, if curr_map doesn't get it, then we don't need and will drop > >it anyway: > > But as above code, curr_dso is passed to dsos__add after curr_map is put. > Even if the curr_map is hold by kmaps, isn't the kmaps controlled by other pthreads? > If no, I'm OK if we move above dsos__add() before map__put() for safety, because > curr_dso is held by curr_map at that point. Good catch, so I'll do as you suggest and move dsos__add() to before we drop that map reference, as then we're sure that we hold it and it holds the dso. > Thank you, > > > > >diff --git a/tools/perf/util/symbol-elf.c b/tools/perf/util/symbol-elf.c > >index 53f19968bfa2..84d787074152 100644 > >--- a/tools/perf/util/symbol-elf.c > >+++ b/tools/perf/util/symbol-elf.c > >@@ -1026,8 +1026,8 @@ int dso__load_sym(struct dso *dso, struct map *map, > > curr_dso->long_name_len = dso->long_name_len; > > curr_map = map__new2(start, curr_dso, > > map->type); > >+ dso__put(curr_dso); > > if (curr_map == NULL) { > >- dso__put(curr_dso); > > goto out_elf_end; > > } > > if (adjust_kernel_syms) { -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/