From patchwork Mon Feb 22 09:11:06 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Wang Nan X-Patchwork-Id: 62514 Delivered-To: patch@linaro.org Received: by 10.112.43.199 with SMTP id y7csp1117841lbl; Mon, 22 Feb 2016 01:29:45 -0800 (PST) X-Received: by 10.66.140.14 with SMTP id rc14mr36784617pab.65.1456133385436; Mon, 22 Feb 2016 01:29:45 -0800 (PST) Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id hq1si38608501pac.56.2016.02.22.01.29.45; Mon, 22 Feb 2016 01:29:45 -0800 (PST) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754128AbcBVJ3f (ORCPT + 30 others); Mon, 22 Feb 2016 04:29:35 -0500 Received: from szxga02-in.huawei.com ([119.145.14.65]:56079 "EHLO szxga02-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753558AbcBVJOC (ORCPT ); Mon, 22 Feb 2016 04:14:02 -0500 Received: from 172.24.1.48 (EHLO szxeml431-hub.china.huawei.com) ([172.24.1.48]) by szxrg02-dlp.huawei.com (MOS 4.3.7-GA FastPath queued) with ESMTP id DBU58526; Mon, 22 Feb 2016 17:12:14 +0800 (CST) Received: from linux-4hy3.site (10.107.193.248) by szxeml431-hub.china.huawei.com (10.82.67.208) with Microsoft SMTP Server id 14.3.235.1; Mon, 22 Feb 2016 17:12:05 +0800 From: Wang Nan To: Alexei Starovoitov , Arnaldo Carvalho de Melo , Arnaldo Carvalho de Melo , Brendan Gregg CC: Adrian Hunter , Cody P Schafer , "David S. Miller" , He Kuang , =?UTF-8?q?J=C3=A9r=C3=A9mie=20Galarneau?= , Jiri Olsa , Kirill Smelkov , Li Zefan , Masami Hiramatsu , Namhyung Kim , Peter Zijlstra , , Wang Nan , Subject: [PATCH 39/48] perf tools: Detect avalibility of write_backward Date: Mon, 22 Feb 2016 09:11:06 +0000 Message-ID: <1456132275-98875-40-git-send-email-wangnan0@huawei.com> X-Mailer: git-send-email 1.8.3.4 In-Reply-To: <1456132275-98875-1-git-send-email-wangnan0@huawei.com> References: <1456132275-98875-1-git-send-email-wangnan0@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.107.193.248] X-CFilter-Loop: Reflected X-Mirapoint-Virus-RAPID-Raw: score=unknown(0), refid=str=0001.0A020202.56CAD0EF.010E, ss=1, re=0.000, recu=0.000, reip=0.000, cl=1, cld=1, fgs=0, ip=0.0.0.0, so=2013-06-18 04:22:30, dmn=2013-03-21 17:37:32 X-Mirapoint-Loop-Id: c57983f0faa4a9ce5cc2c4cbf2660017 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Detect avalibility of write_backward and save the result into record_opts. With write_backward the start pointer of a ring buffer mapped read only can be found reliably. Signed-off-by: Wang Nan Signed-off-by: He Kuang Cc: Arnaldo Carvalho de Melo Cc: Jiri Olsa Cc: Masami Hiramatsu Cc: Namhyung Kim Cc: Zefan Li Cc: pi3orama@163.com --- tools/perf/perf.h | 1 + tools/perf/util/record.c | 11 +++++++++++ 2 files changed, 12 insertions(+) -- 1.8.3.4 diff --git a/tools/perf/perf.h b/tools/perf/perf.h index 5381a01..198345e 100644 --- a/tools/perf/perf.h +++ b/tools/perf/perf.h @@ -73,6 +73,7 @@ struct record_opts { bool sample_transaction; unsigned initial_delay; bool use_clockid; + bool has_write_backward; clockid_t clockid; unsigned int proc_map_timeout; }; diff --git a/tools/perf/util/record.c b/tools/perf/util/record.c index 0467367..d01f155 100644 --- a/tools/perf/util/record.c +++ b/tools/perf/util/record.c @@ -85,6 +85,11 @@ static void perf_probe_comm_exec(struct perf_evsel *evsel) evsel->attr.comm_exec = 1; } +static void perf_probe_write_backward(struct perf_evsel *evsel) +{ + evsel->attr.write_backward = 1; +} + static void perf_probe_context_switch(struct perf_evsel *evsel) { evsel->attr.context_switch = 1; @@ -105,6 +110,11 @@ bool perf_can_record_switch_events(void) return perf_probe_api(perf_probe_context_switch); } +static bool perf_can_write_backward(void) +{ + return perf_probe_api(perf_probe_write_backward); +} + bool perf_can_record_cpu_wide(void) { struct perf_event_attr attr = { @@ -235,6 +245,7 @@ static int record_opts__config_freq(struct record_opts *opts) int record_opts__config(struct record_opts *opts) { + opts->has_write_backward = perf_can_write_backward(); return record_opts__config_freq(opts); }