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=-6.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,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 A72DAC433DF for ; Tue, 7 Jul 2020 15:16:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7FC8E20663 for ; Tue, 7 Jul 2020 15:16:03 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="a8V/2Meg" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728874AbgGGPQB (ORCPT ); Tue, 7 Jul 2020 11:16:01 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59628 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728100AbgGGPQA (ORCPT ); Tue, 7 Jul 2020 11:16:00 -0400 Received: from mail-pg1-x542.google.com (mail-pg1-x542.google.com [IPv6:2607:f8b0:4864:20::542]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 76D89C061755 for ; Tue, 7 Jul 2020 08:16:00 -0700 (PDT) Received: by mail-pg1-x542.google.com with SMTP id j19so13282636pgm.11 for ; Tue, 07 Jul 2020 08:16:00 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=v+GP/QfgjGR3mjxU9s42DqxMpQEDri5uHWLzxTvF4II=; b=a8V/2Megc0AlbIJy0BpS4/HUT4ZrPEDL7dS41uTS9obgKmvWjnxedjcHCNbxg8m04U vgxo1QlMfZcIziru05ft0EwjYTF4Wt8mNH7Cnu4LVs8QvoBjL3Tosg5gOEOeBXOAddB4 54uP0IrrVNB0KND2cUhamY5Iunf4Qb5pdxIJFxlbxliXPgHD6s1ZQGNL3zsqs/rszhyg yxlQT0ewFZPHQy95JIRj5kF+HzW9lCTLeBupvqyO9X6sAH3YMvwXkw2CHNTEuvsXjVdT BX1ev+dTLA7wikmQmGtKzmjFWp5QmwWC4VbABNjIKypILdarHgjbAiN8CjhqOgY+icbr xUXA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=v+GP/QfgjGR3mjxU9s42DqxMpQEDri5uHWLzxTvF4II=; b=qRR2JaPfYH4cPA26PaotxVUfwtHIj0atEBEyjo6ASSonQv172r+3RqyoNDd9ivWFIC c6nGomFxLtqVDmi5cYbK81ShRyb5ytgNBAcppOZIDd6heUsFcOM1Qwc/C7/CIeqow54R vzOuhwdQpIiKKkQLx5sqxi8rvIMtAYsTFvhk6NdkYLiHR4nJktsrWI5WyHP35lKdxn4t NFZTZSAshVEmjhKfZibhofYY1WtOqg827SuJ54x9mv7j3CobZxX/f08w8Ug2aVxAfvoW T70DnYfhdIIteeVMKiU51oWhUwiY0XsW9+ckgTT4mKuTYJsVeWxiC5lQayCpSvJKtls7 WcmA== X-Gm-Message-State: AOAM532i2+SwYZi0kKe+sGbCT+z2FbwK6Yky3iZfyvc0FRdPH3LI2YEW rD8ZRm8acAHCbn4Ni59gavI= X-Google-Smtp-Source: ABdhPJzIQU08zY/vwhj5vkqtlNcOPrKuwA8GEKqF+ctz9lRxShzJxVZwubE4tzMQYQcC9OEg/iVx1w== X-Received: by 2002:a62:cfc1:: with SMTP id b184mr12171884pfg.153.1594134959979; Tue, 07 Jul 2020 08:15:59 -0700 (PDT) Received: from mail.google.com ([149.248.10.52]) by smtp.gmail.com with ESMTPSA id m92sm2978112pje.13.2020.07.07.08.15.43 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 07 Jul 2020 08:15:59 -0700 (PDT) Date: Tue, 7 Jul 2020 23:15:38 +0800 From: Changbin Du To: Namhyung Kim Cc: Changbin Du , Jiri Olsa , Arnaldo Carvalho de Melo , Peter Zijlstra , Ingo Molnar , Steven Rostedt , linux-kernel Subject: Re: [PATCH v2 02/15] perf ftrace: add option '-F/--funcs' to list available functions Message-ID: <20200707151538.ga65xtkwhqegckud@mail.google.com> References: <20200627133654.64863-1-changbin.du@gmail.com> <20200627133654.64863-3-changbin.du@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Jul 03, 2020 at 02:58:19PM +0900, Namhyung Kim wrote: > On Sat, Jun 27, 2020 at 10:37 PM 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 c5718503eded..e793118e83a9 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) > > +{ > > + 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; > > It seems the return value cannot be 0? > If all above success, the return value is 0. > Thanks > Namhyung > > > + > > +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, > > -- > > 2.25.1 > > -- Cheers, Changbin Du