From patchwork Fri Sep 17 15:43:44 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Daniel Bristot de Oliveira X-Patchwork-Id: 12502661 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=-14.0 required=3.0 tests=BAYES_00,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=unavailable 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 E441EC433F5 for ; Fri, 17 Sep 2021 15:45:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C5BB361241 for ; Fri, 17 Sep 2021 15:45:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S244216AbhIQPq5 convert rfc822-to-8bit (ORCPT ); Fri, 17 Sep 2021 11:46:57 -0400 Received: from us-smtp-delivery-44.mimecast.com ([205.139.111.44]:43826 "EHLO us-smtp-delivery-44.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S244477AbhIQPqy (ORCPT ); Fri, 17 Sep 2021 11:46:54 -0400 Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-314-F6Ozvx26PrGytP2uka6ung-1; Fri, 17 Sep 2021 11:45:26 -0400 X-MC-Unique: F6Ozvx26PrGytP2uka6ung-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 656F11006AA3; Fri, 17 Sep 2021 15:45:24 +0000 (UTC) Received: from x1.bristot.me.homenet.telecomitalia.it (unknown [10.22.17.200]) by smtp.corp.redhat.com (Postfix) with ESMTP id 9D6C05D9C6; Fri, 17 Sep 2021 15:45:21 +0000 (UTC) From: Daniel Bristot de Oliveira To: Steven Rostedt Cc: Jonathan Corbet , Kate Carcia , Daniel Bristot de Oliveira , Ingo Molnar , Tom Zanussi , Masami Hiramatsu , Juri Lelli , Clark Williams , Peter Zijlstra , Thomas Gleixner , Sebastian Andrzej Siewior , linux-rt-users@vger.kernel.org, linux-trace-devel@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [RFC 01/19] trace/osnoise: Do not follow tracing_cpumask Date: Fri, 17 Sep 2021 17:43:44 +0200 Message-Id: In-Reply-To: References: MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=bristot@kernel.org X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-trace-devel@vger.kernel.org In preparation to support multiple instances, decople the osnoise/timelat workload from instance specific tracing_cpumask. Different instances can have conflicing cpumasks, making osnoise workload management needlessly complex. Osnoise already have its global cpu mask. I also thought about using the first instance mask, but the "first" instance could be removed before the others. This also fixes the problem that changing the tracing_mask was not re-starting the trace. Cc: Steven Rostedt Cc: Ingo Molnar Cc: Tom Zanussi Cc: Masami Hiramatsu Cc: Juri Lelli Cc: Clark Williams Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: Sebastian Andrzej Siewior Cc: Daniel Bristot de Oliveira Cc: linux-rt-users@vger.kernel.org Cc: linux-trace-devel@vger.kernel.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Daniel Bristot de Oliveira --- kernel/trace/trace_osnoise.c | 25 +++++++------------------ 1 file changed, 7 insertions(+), 18 deletions(-) diff --git a/kernel/trace/trace_osnoise.c b/kernel/trace/trace_osnoise.c index ce053619f289..7b1f8187764c 100644 --- a/kernel/trace/trace_osnoise.c +++ b/kernel/trace/trace_osnoise.c @@ -1553,13 +1553,10 @@ static int start_per_cpu_kthreads(struct trace_array *tr) cpus_read_lock(); /* - * Run only on CPUs in which trace and osnoise are allowed to run. + * Run only on online CPUs in which trace and osnoise are allowed to + * run. */ - cpumask_and(current_mask, tr->tracing_cpumask, &osnoise_cpumask); - /* - * And the CPU is online. - */ - cpumask_and(current_mask, cpu_online_mask, current_mask); + cpumask_and(current_mask, cpu_online_mask, &osnoise_cpumask); for_each_possible_cpu(cpu) per_cpu(per_cpu_osnoise_var, cpu).kthread = NULL; @@ -1580,10 +1577,8 @@ static int start_per_cpu_kthreads(struct trace_array *tr) #ifdef CONFIG_HOTPLUG_CPU static void osnoise_hotplug_workfn(struct work_struct *dummy) { - struct trace_array *tr = osnoise_trace; unsigned int cpu = smp_processor_id(); - mutex_lock(&trace_types_lock); if (!osnoise_busy) @@ -1595,9 +1590,6 @@ static void osnoise_hotplug_workfn(struct work_struct *dummy) if (!cpumask_test_cpu(cpu, &osnoise_cpumask)) goto out_unlock; - if (!cpumask_test_cpu(cpu, tr->tracing_cpumask)) - goto out_unlock; - start_kthread(cpu); out_unlock: @@ -1700,13 +1692,10 @@ static void osnoise_tracer_stop(struct trace_array *tr); * interface to the osnoise trace. By default, it lists all CPUs, * in this way, allowing osnoise threads to run on any online CPU * of the system. It serves to restrict the execution of osnoise to the - * set of CPUs writing via this interface. Note that osnoise also - * respects the "tracing_cpumask." Hence, osnoise threads will run only - * on the set of CPUs allowed here AND on "tracing_cpumask." Why not - * have just "tracing_cpumask?" Because the user might be interested - * in tracing what is running on other CPUs. For instance, one might - * run osnoise in one HT CPU while observing what is running on the - * sibling HT CPU. + * set of CPUs writing via this interface. Why not use "tracing_cpumask"? + * Because the user might be interested in tracing what is running on + * other CPUs. For instance, one might run osnoise in one HT CPU + * while observing what is running on the sibling HT CPU. */ static ssize_t osnoise_cpus_write(struct file *filp, const char __user *ubuf, size_t count,