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=-10.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS 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 507B0C433E2 for ; Fri, 17 Jul 2020 14:52:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2C30920734 for ; Fri, 17 Jul 2020 14:52:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1594997562; bh=2od25Q1VdQOA69Zrte8drsEjwehuDeHLS7JyAaKmumc=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=w8HDYAgJLcardNCKinCbPwDds5lrWynfX/E6JQinRpOCCGio4NAHWIzE1RKAwGJmC A+rfZcL8AGKb4ffd5ML4kuczPpEbVYqH7QVaILgD36vqzq01wXonukhGUjvwLxgU0A ZqXaZD389yEp6XdYObsoQKQkb601bnj1CRvsz9zU= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726780AbgGQOwk (ORCPT ); Fri, 17 Jul 2020 10:52:40 -0400 Received: from mail.kernel.org ([198.145.29.99]:58162 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726335AbgGQOwk (ORCPT ); Fri, 17 Jul 2020 10:52:40 -0400 Received: from quaco.ghostprotocols.net (unknown [179.97.37.151]) (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 168422070E; Fri, 17 Jul 2020 14:52:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1594997559; bh=2od25Q1VdQOA69Zrte8drsEjwehuDeHLS7JyAaKmumc=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=05gnnOnNZ9i2ge2z54hbQaoELtKOXzoXJQEuxtV6+SKBLuwqYqqEQPa696RHzOnZu ukCWvZweXtnko3BtRp2OctMgF1D0dmgvYS7ho5donabouQVFgvHpmatrQrreLnMrOk BJYRGPxA7Z708A16+8gh+MEgoaoaPeOmT4S6r1aw= Received: by quaco.ghostprotocols.net (Postfix, from userid 1000) id EA3D540482; Fri, 17 Jul 2020 11:52:36 -0300 (-03) Date: Fri, 17 Jul 2020 11:52:36 -0300 From: Arnaldo Carvalho de Melo To: Changbin Du Cc: Jiri Olsa , Peter Zijlstra , Ingo Molnar , Namhyung Kim , Steven Rostedt , linux-kernel@vger.kernel.org Subject: Re: [PATCH v6 02/17] perf ftrace: add option '-F/--funcs' to list available functions Message-ID: <20200717145236.GA712240@kernel.org> References: <20200717143628.47721-1-changbin.du@gmail.com> <20200717143628.47721-3-changbin.du@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200717143628.47721-3-changbin.du@gmail.com> X-Url: http://acmel.wordpress.com Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Em Fri, Jul 17, 2020 at 10:36:13PM +0800, Changbin Du escreveu: > This adds an option '-F/--funcs' to list all available functions to trace, > which is read from tracing file 'available_filter_functions'. I'll apply and add a comment stating that this is the same workflow as for 'perf probe', i.e. stress that the value in 'perf ftrace' as opposed to use 'trace-cmd' or plain using the debugfs/tracefs interface is to have a consistent set of options and procedures accross perf and ftrace, one that allows users to go from: perf trace --pid 1234 to: perf ftrace --pid 1234 to: perf stat --pid 1234 to: perf top --pid 1234 to: perf record --pid 1234 to: perf script --pid 1234 etc and get different views, for live or postmortem analysis. - Arnaldo > $ 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 > > --- > v3: fix return value issue. > v2: option name '-l/--list-functions' -> '-F/--funcs' > --- > tools/perf/Documentation/perf-ftrace.txt | 4 +++ > tools/perf/builtin-ftrace.c | 46 ++++++++++++++++++++++++ > 2 files changed, 50 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..3c0e60fdfe0f 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 +128,46 @@ 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) > +{ > + 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) > + break; > + else 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 +342,9 @@ 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 +514,8 @@ 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, > -- > 2.25.1 > -- - Arnaldo