From nobody Wed Dec 31 16:53:39 2025 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 922BEC4332F for ; Tue, 31 Oct 2023 10:57:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231283AbjJaK5m (ORCPT ); Tue, 31 Oct 2023 06:57:42 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58344 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229436AbjJaK5k (ORCPT ); Tue, 31 Oct 2023 06:57:40 -0400 Received: from szxga08-in.huawei.com (szxga08-in.huawei.com [45.249.212.255]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 23EBE83; Tue, 31 Oct 2023 03:57:37 -0700 (PDT) Received: from kwepemm000003.china.huawei.com (unknown [172.30.72.56]) by szxga08-in.huawei.com (SkyGuard) with ESMTP id 4SKRpy59WRz1P7f8; Tue, 31 Oct 2023 18:54:34 +0800 (CST) Received: from ubuntu2204.huawei.com (10.67.174.22) by kwepemm000003.china.huawei.com (7.193.23.66) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.31; Tue, 31 Oct 2023 18:57:34 +0800 From: Yang Jihong To: , , , , , , , , , , CC: Subject: [PATCH] perf tools: Add --debug-file option to redirect debug output Date: Tue, 31 Oct 2023 10:55:23 +0000 Message-ID: <20231031105523.1472558-1-yangjihong1@huawei.com> X-Mailer: git-send-email 2.34.1 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Originating-IP: [10.67.174.22] X-ClientProxiedBy: dggems705-chm.china.huawei.com (10.3.19.182) To kwepemm000003.china.huawei.com (7.193.23.66) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" Currently, debug messages is output to stderr, add --debug-file option to support redirection to a specified file. Some test scenarios: # perf --list-opts --help --version --exec-path --html-path --paginate --no-pager --debugfs-= dir --buildid-dir --list-cmds --list-opts --debug --debug-file # perf --debug-file No path given for --debug-file. Usage: perf [--version] [--help] [OPTIONS] COMMAND [ARGS] # perf --debug-file /sys/perf.log record -v true Open debug file '/sys/perf.log' failed: Permission denied Usage: perf [--version] [--help] [OPTIONS] COMMAND [ARGS] # perf --debug-file /tmp/perf.log record -v true [ perf record: Woken up 1 times to write data ] [ perf record: Captured and wrote 0.013 MB perf.data (26 samples) ] # cat /tmp/perf.log DEBUGINFOD_URLS=3D Using CPUID GenuineIntel-6-3E-4 nr_cblocks: 0 affinity: SYS mmap flush: 1 comp level: 0 mmap size 528384B Control descriptor is not initialized mmap size 528384B Looking at the vmlinux_path (8 entries long) Using /proc/kcore for kernel data Using /proc/kallsyms for symbols symbol:unmap_start file:(null) line:0 offset:0 return:0 lazy:(null) symbol:unmap_complete file:(null) line:0 offset:0 return:0 lazy:(null) symbol:map_start file:(null) line:0 offset:0 return:0 lazy:(null) symbol:map_complete file:(null) line:0 offset:0 return:0 lazy:(null) symbol:reloc_start file:(null) line:0 offset:0 return:0 lazy:(null) symbol:reloc_complete file:(null) line:0 offset:0 return:0 lazy:(null) symbol:init_start file:(null) line:0 offset:0 return:0 lazy:(null) symbol:init_complete file:(null) line:0 offset:0 return:0 lazy:(null) symbol:lll_lock_wait_private file:(null) line:0 offset:0 return:0 lazy:(n= ull) symbol:lll_lock_wait file:(null) line:0 offset:0 return:0 lazy:(null) symbol:setjmp file:(null) line:0 offset:0 return:0 lazy:(null) symbol:longjmp file:(null) line:0 offset:0 return:0 lazy:(null) symbol:longjmp_target file:(null) line:0 offset:0 return:0 lazy:(null) failed to write feature HYBRID_TOPOLOGY Signed-off-by: Yang Jihong Acked-by: Arnaldo Carvalho de Melo --- tools/perf/Documentation/perf.txt | 3 +++ tools/perf/perf.c | 30 ++++++++++++++++++++++++++++++ 2 files changed, 33 insertions(+) diff --git a/tools/perf/Documentation/perf.txt b/tools/perf/Documentation/p= erf.txt index ba3df49c169d..a7cf7bc2f968 100644 --- a/tools/perf/Documentation/perf.txt +++ b/tools/perf/Documentation/perf.txt @@ -64,6 +64,9 @@ OPTIONS perf-event-open - Print perf_event_open() arguments and return value =20 +--debug-file:: + Write debug output to a specified file. + DESCRIPTION ----------- Performance counters for Linux are a new kernel-based subsystem diff --git a/tools/perf/perf.c b/tools/perf/perf.c index d3fc8090413c..921bee0a6437 100644 --- a/tools/perf/perf.c +++ b/tools/perf/perf.c @@ -39,6 +39,7 @@ #include =20 static int use_pager =3D -1; +static FILE *debug_fp =3D NULL; =20 struct cmd_struct { const char *cmd; @@ -162,6 +163,19 @@ static void commit_pager_choice(void) } } =20 +static int set_debug_file(const char *path) +{ + debug_fp =3D fopen(path, "w"); + if (!debug_fp) { + fprintf(stderr, "Open debug file '%s' failed: %s\n", + path, strerror(errno)); + return -1; + } + + debug_set_file(debug_fp); + return 0; +} + struct option options[] =3D { OPT_ARGUMENT("help", "help"), OPT_ARGUMENT("version", "version"), @@ -174,6 +188,7 @@ struct option options[] =3D { OPT_ARGUMENT("list-cmds", "list-cmds"), OPT_ARGUMENT("list-opts", "list-opts"), OPT_ARGUMENT("debug", "debug"), + OPT_ARGUMENT("debug-file", "debug-file"), OPT_END() }; =20 @@ -287,6 +302,18 @@ static int handle_options(const char ***argv, int *arg= c, int *envchanged) =20 (*argv)++; (*argc)--; + } else if (!strcmp(cmd, "--debug-file")) { + if (*argc < 2) { + fprintf(stderr, "No path given for --debug-file.\n"); + usage(perf_usage_string); + } + + if (set_debug_file((*argv)[1])) + usage(perf_usage_string); + + (*argv)++; + (*argc)--; + } else { fprintf(stderr, "Unknown option: %s\n", cmd); usage(perf_usage_string); @@ -547,5 +574,8 @@ int main(int argc, const char **argv) fprintf(stderr, "Failed to run command '%s': %s\n", cmd, str_error_r(errno, sbuf, sizeof(sbuf))); out: + if (debug_fp) + fclose(debug_fp); + return 1; } --=20 2.34.1