From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932572AbcDNOWv (ORCPT ); Thu, 14 Apr 2016 10:22:51 -0400 Received: from szxga03-in.huawei.com ([119.145.14.66]:61643 "EHLO szxga03-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755867AbcDNOWq (ORCPT ); Thu, 14 Apr 2016 10:22:46 -0400 From: Wang Nan To: CC: , , Wang Nan , He Kuang , "Arnaldo Carvalho de Melo" , Adrian Hunter , Jiri Olsa , Masami Hiramatsu , Namhyung Kim , Zefan Li Subject: [PATCH v2 4/6] perf record: Disable buildid cache options by default in switch output mode Date: Thu, 14 Apr 2016 14:22:03 +0000 Message-ID: <1460643725-167413-5-git-send-email-wangnan0@huawei.com> X-Mailer: git-send-email 1.8.3.4 In-Reply-To: <1460643725-167413-1-git-send-email-wangnan0@huawei.com> References: <1460643725-167413-1-git-send-email-wangnan0@huawei.com> MIME-Version: 1.0 Content-Type: text/plain X-Originating-IP: [10.107.193.248] X-CFilter-Loop: Reflected X-Mirapoint-Virus-RAPID-Raw: score=unknown(0), refid=str=0001.0A020202.570FA7A1.01C6,ss=1,re=0.000,recu=0.000,reip=0.000,cl=1,cld=1,fgs=0, ip=0.0.0.0, so=2013-05-26 15:14:31, dmn=2013-03-21 17:37:32 X-Mirapoint-Loop-Id: c827f3a66afa11c90097bcf9664b0a2c Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Cost of buildid cache processing is high: reading all events in output perf.data, opening each elf file to read buildids then copying them into ~/.debug directory. In switch output mode, these heavy works block perf from receiving perf events for too long. Enable no-buildid and no-buildid-cache by default if --switch-output is provided. Still allow user use --no-no-buildid to explicitly enable buildid in this case. Signed-off-by: Wang Nan Signed-off-by: He Kuang Cc: Arnaldo Carvalho de Melo Cc: Adrian Hunter Cc: Jiri Olsa Cc: Masami Hiramatsu Cc: Namhyung Kim Cc: Zefan Li Cc: pi3orama@163.com --- tools/perf/builtin-record.c | 30 +++++++++++++++++++++++++++++- 1 file changed, 29 insertions(+), 1 deletion(-) diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c index 32db7a7..f561a1b 100644 --- a/tools/perf/builtin-record.c +++ b/tools/perf/builtin-record.c @@ -1374,8 +1374,36 @@ int cmd_record(int argc, const char **argv, const char *prefix __maybe_unused) "If some relocation was applied (e.g. kexec) symbols may be misresolved\n" "even with a suitable vmlinux or kallsyms file.\n\n"); - if (rec->no_buildid_cache || rec->no_buildid) + if (rec->no_buildid_cache || rec->no_buildid) { disable_buildid_cache(); + } else if (rec->switch_output) { + /* + * In 'perf record --switch-output', disable buildid + * generation by default to reduce data file switching + * overhead. Still generate buildid if they are required + * explicitly using + * + * perf record --signal-trigger --no-no-buildid \ + * --no-no-buildid-cache + * + * Following code equals to: + * + * if ((rec->no_buildid || !rec->no_buildid_set) && + * (rec->no_buildid_cache || !rec->no_buildid_cache_set)) + * disable_buildid_cache(); + */ + bool disable = true; + + if (rec->no_buildid_set && !rec->no_buildid) + disable = false; + if (rec->no_buildid_cache_set && !rec->no_buildid_cache) + disable = false; + if (disable) { + rec->no_buildid = true; + rec->no_buildid_cache = true; + disable_buildid_cache(); + } + } if (rec->evlist->nr_entries == 0 && perf_evlist__add_default(rec->evlist) < 0) { -- 1.8.3.4