From nobody Sat Feb 7 21:20:38 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 8BAC6C43217 for ; Thu, 24 Nov 2022 14:51:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229931AbiKXOv1 (ORCPT ); Thu, 24 Nov 2022 09:51:27 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55140 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229526AbiKXOvA (ORCPT ); Thu, 24 Nov 2022 09:51:00 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EE6C4134118 for ; Thu, 24 Nov 2022 06:50:49 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id AE47CB82846 for ; Thu, 24 Nov 2022 14:50:48 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4A27CC4314D; Thu, 24 Nov 2022 14:50:47 +0000 (UTC) Received: from rostedt by gandalf.local.home with local (Exim 4.96) (envelope-from ) id 1oyDYs-001X50-1L; Thu, 24 Nov 2022 09:50:46 -0500 Message-ID: <20221124145046.301211304@goodmis.org> User-Agent: quilt/0.66 Date: Thu, 24 Nov 2022 09:50:25 -0500 From: Steven Rostedt To: linux-kernel@vger.kernel.org Cc: Masami Hiramatsu , Andrew Morton , Daniel Bristot de Oliveira , Jonathan Corbet Subject: [for-next][PATCH 06/11] tracing/osnoise: Add OSNOISE_WORKLOAD option References: <20221124145019.782980678@goodmis.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" From: Daniel Bristot de Oliveira The osnoise tracer is not only a tracer, and a set of tracepoints, but also a workload dispatcher. In preparation for having other workloads, e.g., in user-space, add an option to avoid dispatching the workload. By not dispatching the workload, the osnoise: tracepoints become generic events to measure the execution time of *any* task on Linux. For example: # cd /sys/kernel/tracing/ # cat osnoise/options DEFAULTS OSNOISE_WORKLOAD # echo NO_OSNOISE_WORKLOAD > osnoise/options # cat osnoise/options NO_DEFAULTS NO_OSNOISE_WORKLOAD # echo osnoise > set_event # echo osnoise > current_tracer # tail -8 trace make-94722 [002] d..3. 1371.794507: thread_noise: make:94722 s= tart 1371.794302286 duration 200897 ns sh-121042 [020] d..3. 1371.794534: thread_noise: sh:121042 = start 1371.781610976 duration 8943683 ns make-121097 [005] d..3. 1371.794542: thread_noise: make:121097 = start 1371.794481522 duration 60444 ns <...>-40 [005] d..3. 1371.794550: thread_noise: migration/5:40 s= tart 1371.794542256 duration 7154 ns -0 [018] dNh2. 1371.794554: irq_noise: reschedule:253 star= t 1371.794553547 duration 40 ns -0 [018] dNh2. 1371.794561: irq_noise: local_timer:236 sta= rt 1371.794556222 duration 4890 ns -0 [018] .Ns2. 1371.794563: softirq_noise: SCHED:7 star= t 1371.794561803 duration 992 ns -0 [018] d..3. 1371.794566: thread_noise: swapper/18:0 sta= rt 1371.781368110 duration 13191798 ns In preparation for the rtla exec_time tracer/tool and rtla osnoise --user option. Link: https://lkml.kernel.org/r/f5cfbd37aefd419eefe9243b4d2fc38ed5753fe4.16= 68692096.git.bristot@kernel.org Cc: Daniel Bristot de Oliveira Cc: Masami Hiramatsu Cc: Jonathan Corbet Signed-off-by: Daniel Bristot de Oliveira Signed-off-by: Steven Rostedt (Google) --- kernel/trace/trace_osnoise.c | 28 ++++++++++++++++++++++------ 1 file changed, 22 insertions(+), 6 deletions(-) diff --git a/kernel/trace/trace_osnoise.c b/kernel/trace/trace_osnoise.c index 17b77fe3950b..3f10dd1f2f1c 100644 --- a/kernel/trace/trace_osnoise.c +++ b/kernel/trace/trace_osnoise.c @@ -53,12 +53,13 @@ */ enum osnoise_options_index { OSN_DEFAULTS =3D 0, + OSN_WORKLOAD, OSN_MAX }; =20 -static const char * const osnoise_options_str[OSN_MAX] =3D { "DEFAULTS" }; +static const char * const osnoise_options_str[OSN_MAX] =3D { "DEFAULTS", "= OSNOISE_WORKLOAD" }; =20 -#define OSN_DEFAULT_OPTIONS 0 +#define OSN_DEFAULT_OPTIONS 0x2 unsigned long osnoise_options =3D OSN_DEFAULT_OPTIONS; =20 /* @@ -1186,11 +1187,12 @@ trace_sched_switch_callback(void *data, bool preemp= t, unsigned int prev_state) { struct osnoise_variables *osn_var =3D this_cpu_osn_var(); + int workload =3D test_bit(OSN_WORKLOAD, &osnoise_options); =20 - if (p->pid !=3D osn_var->pid) + if ((p->pid !=3D osn_var->pid) || !workload) thread_exit(osn_var, p); =20 - if (n->pid !=3D osn_var->pid) + if ((n->pid !=3D osn_var->pid) || !workload) thread_entry(osn_var, n); } =20 @@ -1723,9 +1725,16 @@ static void stop_kthread(unsigned int cpu) struct task_struct *kthread; =20 kthread =3D per_cpu(per_cpu_osnoise_var, cpu).kthread; - if (kthread) + if (kthread) { kthread_stop(kthread); - per_cpu(per_cpu_osnoise_var, cpu).kthread =3D NULL; + per_cpu(per_cpu_osnoise_var, cpu).kthread =3D NULL; + } else { + if (!test_bit(OSN_WORKLOAD, &osnoise_options)) { + per_cpu(per_cpu_osnoise_var, cpu).sampling =3D false; + barrier(); + return; + } + } } =20 /* @@ -1759,6 +1768,13 @@ static int start_kthread(unsigned int cpu) snprintf(comm, 24, "timerlat/%d", cpu); main =3D timerlat_main; } else { + /* if no workload, just return */ + if (!test_bit(OSN_WORKLOAD, &osnoise_options)) { + per_cpu(per_cpu_osnoise_var, cpu).sampling =3D true; + barrier(); + return 0; + } + snprintf(comm, 24, "osnoise/%d", cpu); } =20 --=20 2.35.1