From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-11.5 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_2 autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0D3E0C433E3 for ; Fri, 17 Jul 2020 15:05:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E7E742076D for ; Fri, 17 Jul 2020 15:05:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726233AbgGQPFH (ORCPT ); Fri, 17 Jul 2020 11:05:07 -0400 Received: from mail.kernel.org ([198.145.29.99]:37320 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726198AbgGQPFH (ORCPT ); Fri, 17 Jul 2020 11:05:07 -0400 Received: from oasis.local.home (cpe-66-24-58-225.stny.res.rr.com [66.24.58.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 3CCDE206F4; Fri, 17 Jul 2020 15:05:06 +0000 (UTC) Date: Fri, 17 Jul 2020 11:05:04 -0400 From: Steven Rostedt To: Changbin Du Cc: Jiri Olsa , Arnaldo Carvalho de Melo , Peter Zijlstra , Ingo Molnar , Namhyung Kim , linux-kernel@vger.kernel.org, "linux-trace-devel@vger.kernel.org" Subject: Re: [PATCH v5 02/17] perf ftrace: add option '-F/--funcs' to list available functions Message-ID: <20200717110504.1650fbdc@oasis.local.home> In-Reply-To: <20200711124035.6513-3-changbin.du@gmail.com> References: <20200711124035.6513-1-changbin.du@gmail.com> <20200711124035.6513-3-changbin.du@gmail.com> X-Mailer: Claws Mail 3.17.3 (GTK+ 2.24.32; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-trace-devel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-trace-devel@vger.kernel.org On Sat, 11 Jul 2020 20:40:20 +0800 Changbin Du wrote: > This adds an option '-F/--funcs' to list all available functions to trace, > which is read from tracing file 'available_filter_functions'. > > $ sudo ./perf ftrace -F | head > trace_initcall_finish_cb > initcall_blacklisted > do_one_initcall > do_one_initcall > trace_initcall_start_cb > run_init_process > try_to_run_init_process > match_dev_by_label > match_dev_by_uuid > rootfs_init_fs_context > > Signed-off-by: Changbin Du > > --- > v2: option name '-l/--list-functions' -> '-F/--funcs' > --- > tools/perf/Documentation/perf-ftrace.txt | 4 +++ > tools/perf/builtin-ftrace.c | 43 ++++++++++++++++++++++++ > 2 files changed, 47 insertions(+) > > diff --git a/tools/perf/Documentation/perf-ftrace.txt b/tools/perf/Documentation/perf-ftrace.txt > index 952e46669168..d79560dea19f 100644 > --- a/tools/perf/Documentation/perf-ftrace.txt > +++ b/tools/perf/Documentation/perf-ftrace.txt > @@ -30,6 +30,10 @@ OPTIONS > --verbose=:: > Verbosity level. > > +-F:: > +--funcs:: > + List all available functions to trace. > + > -p:: > --pid=:: > Trace on existing process id (comma separated list). > diff --git a/tools/perf/builtin-ftrace.c b/tools/perf/builtin-ftrace.c > index 5f53da87040d..244cc8e6bd60 100644 > --- a/tools/perf/builtin-ftrace.c > +++ b/tools/perf/builtin-ftrace.c > @@ -32,6 +32,7 @@ struct perf_ftrace { > struct evlist *evlist; > struct target target; > const char *tracer; > + bool list_avail_functions; > struct list_head filters; > struct list_head notrace; > struct list_head graph_funcs; > @@ -127,6 +128,43 @@ static int append_tracing_file(const char *name, const char *val) > return __write_tracing_file(name, val, true); > } > > +static int read_tracing_file_to_stdout(const char *name) > +{ All this is looking like its duplicating code that we are working on for libtracefs. Would you like to start contributing to that, and when we get the libtracefs.so packed in distributions, we can easily create the perf ftrace without having to rewrite the wheel 10 times? -- Steve > + char buf[4096]; > + char *file; > + int fd; > + int ret = -1; > + > + file = get_tracing_file(name); > + if (!file) { > + pr_debug("cannot get tracing file: %s\n", name); > + return -1; > + } > + > + fd = open(file, O_RDONLY); > + if (fd < 0) { > + pr_debug("cannot open tracing file: %s: %s\n", > + name, str_error_r(errno, buf, sizeof(buf))); > + goto out; > + } > + > + /* read contents to stdout */ > + while (true) { > + int n = read(fd, buf, sizeof(buf)); > + if (n <= 0) > + goto out_close; > + if (fwrite(buf, n, 1, stdout) != 1) > + goto out_close; > + } > + ret = 0; > + > +out_close: > + close(fd); > +out: > + put_tracing_file(file); > + return ret; > +} > + > static int reset_tracing_cpu(void); > static void reset_tracing_filters(void); > > @@ -301,6 +339,9 @@ static int __cmd_ftrace(struct perf_ftrace *ftrace, int argc, const char **argv) > signal(SIGCHLD, sig_handler); > signal(SIGPIPE, sig_handler); > > + if (ftrace->list_avail_functions) > + return read_tracing_file_to_stdout("available_filter_functions"); > + > if (reset_tracing_files(ftrace) < 0) { > pr_err("failed to reset ftrace\n"); > goto out; > @@ -470,6 +511,8 @@ int cmd_ftrace(int argc, const char **argv) > const struct option ftrace_options[] = { > OPT_STRING('t', "tracer", &ftrace.tracer, "tracer", > "tracer to use: function or function_graph (This option is deprecated)"), > + OPT_BOOLEAN('F', "funcs", &ftrace.list_avail_functions, > + "Show available functions to filter"), > OPT_STRING('p', "pid", &ftrace.target.pid, "pid", > "trace on existing process id"), > OPT_INCR('v', "verbose", &verbose,