From nobody Mon Feb 9 01:22:45 2026 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 C1D89C76195 for ; Fri, 24 Mar 2023 03:29:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230369AbjCXD3E (ORCPT ); Thu, 23 Mar 2023 23:29:04 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46250 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229484AbjCXD3B (ORCPT ); Thu, 23 Mar 2023 23:29:01 -0400 Received: from szxga02-in.huawei.com (szxga02-in.huawei.com [45.249.212.188]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9EDEA212A4; Thu, 23 Mar 2023 20:28:59 -0700 (PDT) Received: from kwepemm600003.china.huawei.com (unknown [172.30.72.57]) by szxga02-in.huawei.com (SkyGuard) with ESMTP id 4PjSJn5BpGzSp8n; Fri, 24 Mar 2023 11:25:29 +0800 (CST) Received: from localhost.localdomain (10.67.174.95) by kwepemm600003.china.huawei.com (7.193.23.202) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.21; Fri, 24 Mar 2023 11:28:57 +0800 From: Yang Jihong To: , , , , , , , , , , CC: Subject: [PATCH] perf ftrace: Make system wide the default target for latency subcommand Date: Fri, 24 Mar 2023 03:27:02 +0000 Message-ID: <20230324032702.109964-1-yangjihong1@huawei.com> X-Mailer: git-send-email 2.30.GIT MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Originating-IP: [10.67.174.95] X-ClientProxiedBy: dggems705-chm.china.huawei.com (10.3.19.182) To kwepemm600003.china.huawei.com (7.193.23.202) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" If no target is specified for 'latency' subcommand, the execution fails because - 1 (invalid value) is written to set_ftrace_pid tracefs file. Make system wide the default target, which is the same as the default behavior of 'trace' subcommand. Before the fix: # perf ftrace latency -T schedule failed to set ftrace pid After the fix: # perf ftrace latency -T schedule ^C# DURATION | COUNT | GRAPH = | 0 - 1 us | 0 | = | 1 - 2 us | 0 | = | 2 - 4 us | 0 | = | 4 - 8 us | 2828 | #### = | 8 - 16 us | 23953 | ######################################## = | 16 - 32 us | 408 | = | 32 - 64 us | 318 | = | 64 - 128 us | 4 | = | 128 - 256 us | 3 | = | 256 - 512 us | 0 | = | 512 - 1024 us | 1 | = | 1 - 2 ms | 4 | = | 2 - 4 ms | 0 | = | 4 - 8 ms | 0 | = | 8 - 16 ms | 0 | = | 16 - 32 ms | 0 | = | 32 - 64 ms | 0 | = | 64 - 128 ms | 0 | = | 128 - 256 ms | 4 | = | 256 - 512 ms | 2 | = | 512 - 1024 ms | 0 | = | 1 - ... s | 0 | = | Fixes: 53be50282269 ("perf ftrace: Add 'latency' subcommand") Signed-off-by: Yang Jihong Acked-by: Namhyung Kim --- tools/perf/builtin-ftrace.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/tools/perf/builtin-ftrace.c b/tools/perf/builtin-ftrace.c index d7fe00f66b83..fb1b66ef2e16 100644 --- a/tools/perf/builtin-ftrace.c +++ b/tools/perf/builtin-ftrace.c @@ -1228,10 +1228,12 @@ int cmd_ftrace(int argc, const char **argv) goto out_delete_filters; } =20 + /* Make system wide (-a) the default target. */ + if (!argc && target__none(&ftrace.target)) + ftrace.target.system_wide =3D true; + switch (subcmd) { case PERF_FTRACE_TRACE: - if (!argc && target__none(&ftrace.target)) - ftrace.target.system_wide =3D true; cmd_func =3D __cmd_ftrace; break; case PERF_FTRACE_LATENCY: --=20 2.30.GIT