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=ham 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 F3C1BC433E1 for ; Fri, 14 Aug 2020 11:35:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CEB7020829 for ; Fri, 14 Aug 2020 11:35:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1597404942; bh=+SScuk5qKesicxoXWFToSaNdAgaR48N+FzRr69hLNUI=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=UvIbUHrR+yRl2Fr8iG5u4/aas8SBsCsywO2WGIDBo7+p2Ueccw0q6EmCrQHItCTNf 6o50YQ6JIAyVJiK+kjuyGZKt8RW6hECWdmp+eN8gnwZJqipoQ8DVzV03UDnmN/tWsh rb3i7dfw7FOw2Yxj1qvs/v+k5Q8cL3NJBcGztdbo= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728028AbgHNLfj (ORCPT ); Fri, 14 Aug 2020 07:35:39 -0400 Received: from mail.kernel.org ([198.145.29.99]:57250 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726185AbgHNLfh (ORCPT ); Fri, 14 Aug 2020 07:35:37 -0400 Received: from quaco.ghostprotocols.net (177.207.136.251.dynamic.adsl.gvt.net.br [177.207.136.251]) (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 688A320771; Fri, 14 Aug 2020 11:35:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1597404937; bh=+SScuk5qKesicxoXWFToSaNdAgaR48N+FzRr69hLNUI=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=0F5u6IEWSPAtra/Ni8o34VKtJ2v8tUrF+3882Ir3HYULk1ap8G1+qPhlQODEay0cm szuRKEm2y+mXi/wU0G3qjGBrnAiKN28fv89YTxJ/tYe/0rPr1aR6ZX4xQs3ExZagyO hMmnqZ0DMB27PdStrUngtiXoHVsn1fqN2QugX4Ak= Received: by quaco.ghostprotocols.net (Postfix, from userid 1000) id 7F2FD4097F; Fri, 14 Aug 2020 08:35:35 -0300 (-03) Date: Fri, 14 Aug 2020 08:35:35 -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 v8 02/18] perf ftrace: add option '-F/--funcs' to list available functions Message-ID: <20200814113535.GS13995@kernel.org> References: <20200808023141.14227-1-changbin.du@gmail.com> <20200808023141.14227-3-changbin.du@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200808023141.14227-3-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 Sat, Aug 08, 2020 at 10:31:25AM +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'. > > $ 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 821d4d334a09..4f5628445a63 100644 > --- a/tools/perf/Documentation/perf-ftrace.txt > +++ b/tools/perf/Documentation/perf-ftrace.txt > @@ -31,6 +31,10 @@ 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 048a11192b59..1ebf71ecc1a8 100644 > --- a/tools/perf/builtin-ftrace.c > +++ b/tools/perf/builtin-ftrace.c > @@ -33,6 +33,7 @@ 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; > @@ -128,6 +129,46 @@ 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); > > @@ -302,6 +343,9 @@ 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; > @@ -487,6 +531,8 @@ int cmd_ftrace(int argc, const char **argv) > const struct option ftrace_options[] = { > OPT_STRING('t', "tracer", &ftrace.tracer, "tracer", > "tracer to use: function_graph(default) or function"), > + OPT_BOOLEAN('F', "funcs", &ftrace.list_avail_functions, > + "Show available functions to filter"), A boolean? I guess this can be a first step, but why not do it like 'perf probe' and accept a patterna? Allows for less typing: # perf probe -h -F -F, --funcs <[FILTER]> Show potential probe-able functions. [root@quaco ~]# # perf probe -F '*btf_parse*' btf_parse_hdr btf_parse_str_sec btf_parse_vmlinux # # perf ftrace -F | grep btf_parse btf_parse_str_sec btf_parse_hdr btf_parse_vmlinux # I'm applying this to make progress, but please consider sending a patch to make this behave in the same way as 'perf probe'. - Arnaldo > OPT_STRING('p', "pid", &ftrace.target.pid, "pid", > "trace on existing process id"), > OPT_INCR('v', "verbose", &verbose, > -- > 2.25.1 > -- - Arnaldo