From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753387AbcEYNqA (ORCPT ); Wed, 25 May 2016 09:46:00 -0400 Received: from szxga03-in.huawei.com ([119.145.14.66]:35692 "EHLO szxga03-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753039AbcEYNp5 (ORCPT ); Wed, 25 May 2016 09:45:57 -0400 From: Wang Nan To: CC: , , Wang Nan , He Kuang , "Arnaldo Carvalho de Melo" , Jiri Olsa , Masami Hiramatsu , Namhyung Kim , "Zefan Li" Subject: [PATCH v6 08/10] perf tools: Check write_backward during evlist config Date: Wed, 25 May 2016 13:44:56 +0000 Message-ID: <1464183898-174512-9-git-send-email-wangnan0@huawei.com> X-Mailer: git-send-email 1.8.3.4 In-Reply-To: <1464183898-174512-1-git-send-email-wangnan0@huawei.com> References: <1464183898-174512-1-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=0001.0A020204.5745AC6A.0211,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: 823cbcf67d25be984f65f54ded55ac2e Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Before this patch, when using overwritable ring buffer on an old kernel, error message is misleading: # ~/perf record -m 1 -e raw_syscalls:*/overwrite/ -a Error: The raw_syscalls:sys_enter event is not supported. This patch output clear error message to tell user his/her kernel is too old: # ~/perf record -m 1 -e raw_syscalls:*/overwrite/ -a Reading from overwrite event is not supported by this kernel Error: The raw_syscalls:sys_enter event is not supported. Signed-off-by: Wang Nan Cc: 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/util/evsel.c | 17 +++++------------ tools/perf/util/evsel.h | 13 +++++++++++++ tools/perf/util/record.c | 17 +++++++++++++++++ 3 files changed, 35 insertions(+), 12 deletions(-) diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c index 6330a4f..994310f 100644 --- a/tools/perf/util/evsel.c +++ b/tools/perf/util/evsel.c @@ -29,17 +29,7 @@ #include "trace-event.h" #include "stat.h" -static struct { - bool sample_id_all; - bool exclude_guest; - bool mmap2; - bool cloexec; - bool clockid; - bool clockid_wrong; - bool lbr_flags; - bool write_backward; -} perf_missing_features; - +struct perf_missing_features perf_missing_features; static clockid_t clockid; static int perf_evsel__no_extra_init(struct perf_evsel *evsel __maybe_unused) @@ -684,8 +674,11 @@ static void apply_config_terms(struct perf_evsel *evsel, * possible to set overwrite globally, without config * terms. */ - if (evsel->overwrite) + if (evsel->overwrite) { + WARN_ONCE(perf_missing_features.write_backward, + "Reading from overwrite event is not supported by this kernel\n"); attr->write_backward = 1; + } /* User explicitly set per-event callgraph, clear the old setting and reset. */ if ((callgraph_buf != NULL) || (dump_size > 0)) { diff --git a/tools/perf/util/evsel.h b/tools/perf/util/evsel.h index bce99fa..c9b6716 100644 --- a/tools/perf/util/evsel.h +++ b/tools/perf/util/evsel.h @@ -11,6 +11,19 @@ #include "cpumap.h" #include "counts.h" +struct perf_missing_features { + bool sample_id_all; + bool exclude_guest; + bool mmap2; + bool cloexec; + bool clockid; + bool clockid_wrong; + bool lbr_flags; + bool write_backward; +}; + +extern struct perf_missing_features perf_missing_features; + struct perf_evsel; /* diff --git a/tools/perf/util/record.c b/tools/perf/util/record.c index 481792c..e3ab812 100644 --- a/tools/perf/util/record.c +++ b/tools/perf/util/record.c @@ -90,6 +90,11 @@ static void perf_probe_context_switch(struct perf_evsel *evsel) evsel->attr.context_switch = 1; } +static void perf_probe_write_backward(struct perf_evsel *evsel) +{ + evsel->attr.write_backward = 1; +} + bool perf_can_sample_identifier(void) { return perf_probe_api(perf_probe_sample_identifier); @@ -129,6 +134,17 @@ bool perf_can_record_cpu_wide(void) return true; } +static void perf_check_write_backward(void) +{ + static bool checked = false; + + if (!checked) { + perf_missing_features.write_backward = + !perf_probe_api(perf_probe_write_backward); + checked = true; + } +} + void perf_evlist__config(struct perf_evlist *evlist, struct record_opts *opts, struct callchain_param *callchain) { @@ -136,6 +152,7 @@ void perf_evlist__config(struct perf_evlist *evlist, struct record_opts *opts, bool use_sample_identifier = false; bool use_comm_exec; + perf_check_write_backward(); /* * Set the evsel leader links before we configure attributes, * since some might depend on this info. -- 1.8.3.4