From patchwork Mon Jul 17 18:11:34 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Paul E. McKenney" X-Patchwork-Id: 13316225 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 7CC84C001DE for ; Mon, 17 Jul 2023 18:11:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231308AbjGQSLr (ORCPT ); Mon, 17 Jul 2023 14:11:47 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42236 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231142AbjGQSLo (ORCPT ); Mon, 17 Jul 2023 14:11:44 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 12CA3E6F; Mon, 17 Jul 2023 11:11:42 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 28082611E8; Mon, 17 Jul 2023 18:11:41 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 64B34C4339A; Mon, 17 Jul 2023 18:11:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1689617500; bh=WXMDNs0NKjgJYxezPeNZXXRf2T8Uz/q0zB/XGeUalEU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=qYVZQXwY1x+p2SFAg3b1Yi2EeSpc9tdtf1QRvIbUgJj5SfFvEALvdNSaswcUGc7tq aMYc2cK2zzcoAjCTMJdEL6xwLnPOc89KURa0OlTbv1fJGXRaAlMRH2xOW1CyZ53O/9 JWtYVrqtq9ZuMrM/7W4RVig3+e3yNrbhi/g856QBdqcnE1hxWUA+yhTvEjJTcvmggM A35Oh0mJPKeW1u8NoVFW53qGVRN5Z3tg7X2aPtdu550UM9l7SuSQLoM0h5v03NguO6 R1+F3WXzINVmVibHJeWZZNamiy1oBKcdue10uaYVrBJ7LWEzcj8rpW3sB29cxbiaHv +re2b2aT20CVg== Received: by paulmck-ThinkPad-P17-Gen-1.home (Postfix, from userid 1000) id C04EFCE097F; Mon, 17 Jul 2023 11:11:39 -0700 (PDT) From: "Paul E. McKenney" To: rcu@vger.kernel.org Cc: linux-kernel@vger.kernel.org, kernel-team@meta.com, rostedt@goodmis.org, "Paul E. McKenney" Subject: [PATCH rcu 09/13] rcuscale: Measure RCU Tasks Trace grace-period kthread CPU time Date: Mon, 17 Jul 2023 11:11:34 -0700 Message-Id: <20230717181138.1098063-9-paulmck@kernel.org> X-Mailer: git-send-email 2.40.1 In-Reply-To: References: MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: rcu@vger.kernel.org This commit causes RCU Tasks Trace to output the CPU time consumed by its grace-period kthread. The CPU time is whatever is in the designated task's current->stime field, and thus is controlled by whatever CPU-time accounting scheme is in effect. This output appears in microseconds as follows on the console: rcu_scale: Grace-period kthread CPU time: 42367.037 [ paulmck: Apply Willy Tarreau feedback. ] Signed-off-by: Paul E. McKenney --- kernel/rcu/rcu.h | 3 +++ kernel/rcu/rcuscale.c | 1 + kernel/rcu/tasks.h | 6 ++++++ 3 files changed, 10 insertions(+) diff --git a/kernel/rcu/rcu.h b/kernel/rcu/rcu.h index 98c1544cf572..d58bc0e86769 100644 --- a/kernel/rcu/rcu.h +++ b/kernel/rcu/rcu.h @@ -505,6 +505,9 @@ void rcu_async_relax(void); void rcupdate_announce_bootup_oddness(void); #ifdef CONFIG_TASKS_RCU_GENERIC void show_rcu_tasks_gp_kthreads(void); +# ifdef CONFIG_TASKS_RCU +struct task_struct *get_rcu_tasks_gp_kthread(void); +# endif // # ifdef CONFIG_TASKS_RCU #else /* #ifdef CONFIG_TASKS_RCU_GENERIC */ static inline void show_rcu_tasks_gp_kthreads(void) {} #endif /* #else #ifdef CONFIG_TASKS_RCU_GENERIC */ diff --git a/kernel/rcu/rcuscale.c b/kernel/rcu/rcuscale.c index 7fba3ab66e35..35e06c86acc9 100644 --- a/kernel/rcu/rcuscale.c +++ b/kernel/rcu/rcuscale.c @@ -298,6 +298,7 @@ static struct rcu_scale_ops tasks_ops = { .gp_barrier = rcu_barrier_tasks, .sync = synchronize_rcu_tasks, .exp_sync = synchronize_rcu_tasks, + .rso_gp_kthread = get_rcu_tasks_gp_kthread, .name = "tasks" }; diff --git a/kernel/rcu/tasks.h b/kernel/rcu/tasks.h index 990a6cf5fa35..0f03de023097 100644 --- a/kernel/rcu/tasks.h +++ b/kernel/rcu/tasks.h @@ -1042,6 +1042,12 @@ void show_rcu_tasks_classic_gp_kthread(void) EXPORT_SYMBOL_GPL(show_rcu_tasks_classic_gp_kthread); #endif // !defined(CONFIG_TINY_RCU) +struct task_struct *get_rcu_tasks_gp_kthread(void) +{ + return rcu_tasks.kthread_ptr; +} +EXPORT_SYMBOL_GPL(get_rcu_tasks_gp_kthread); + /* * Contribute to protect against tasklist scan blind spot while the * task is exiting and may be removed from the tasklist. See