From mboxrd@z Thu Jan 1 00:00:00 1970 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=-8.7 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT 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 3B4A7C48BD6 for ; Thu, 27 Jun 2019 07:08:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1B0EE2054F for ; Thu, 27 Jun 2019 07:08:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726500AbfF0HIa (ORCPT ); Thu, 27 Jun 2019 03:08:30 -0400 Received: from lgeamrelo12.lge.com ([156.147.23.52]:48569 "EHLO lgeamrelo11.lge.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1725787AbfF0HIa (ORCPT ); Thu, 27 Jun 2019 03:08:30 -0400 Received: from unknown (HELO lgeamrelo02.lge.com) (156.147.1.126) by 156.147.23.52 with ESMTP; 27 Jun 2019 16:08:27 +0900 X-Original-SENDERIP: 156.147.1.126 X-Original-MAILFROM: byungchul.park@lge.com Received: from unknown (HELO localhost.localdomain) (10.177.222.33) by 156.147.1.126 with ESMTP; 27 Jun 2019 16:08:27 +0900 X-Original-SENDERIP: 10.177.222.33 X-Original-MAILFROM: byungchul.park@lge.com From: Byungchul Park To: paulmck@linux.ibm.com, josh@joshtriplett.org, rostedt@goodmis.org, mathieu.desnoyers@efficios.com, jiangshanlai@gmail.com, joel@joelfernandes.org, rcu@vger.kernel.org Cc: linux-kernel@vger.kernel.org, kernel-team@lge.com Subject: [PATCH v2] rcu: Change return type of rcu_spawn_one_boost_kthread() Date: Thu, 27 Jun 2019 16:07:46 +0900 Message-Id: <1561619266-8850-1-git-send-email-byungchul.park@lge.com> X-Mailer: git-send-email 1.9.1 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello, I tested if the WARN_ON_ONCE() is fired with my box and it was ok. Thanks, Byungchul Changes from v1 -. WARN_ON_ONCE() on failing to create rcu_boost_kthread. -. Changed title and commit message a bit. ---8<--- >From 7100fcf82202f063f70f45def208ea5198412f5a Mon Sep 17 00:00:00 2001 From: Byungchul Park Date: Thu, 27 Jun 2019 15:58:10 +0900 Subject: [PATCH v2] rcu: Change return type of rcu_spawn_one_boost_kthread() The return value of rcu_spawn_one_boost_kthread() is not used any longer. Change return type of that function from int to void. Signed-off-by: Byungchul Park --- kernel/rcu/tree_plugin.h | 17 ++++++++--------- 1 file changed, 8 insertions(+), 9 deletions(-) diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h index 1102765..3c8444e 100644 --- a/kernel/rcu/tree_plugin.h +++ b/kernel/rcu/tree_plugin.h @@ -1131,7 +1131,7 @@ static void rcu_preempt_boost_start_gp(struct rcu_node *rnp) * already exist. We only create this kthread for preemptible RCU. * Returns zero if all is well, a negated errno otherwise. */ -static int rcu_spawn_one_boost_kthread(struct rcu_node *rnp) +static void rcu_spawn_one_boost_kthread(struct rcu_node *rnp) { int rnp_index = rnp - rcu_get_root(); unsigned long flags; @@ -1139,25 +1139,24 @@ static int rcu_spawn_one_boost_kthread(struct rcu_node *rnp) struct task_struct *t; if (!IS_ENABLED(CONFIG_PREEMPT_RCU)) - return 0; + return; if (!rcu_scheduler_fully_active || rcu_rnp_online_cpus(rnp) == 0) - return 0; + return; rcu_state.boost = 1; if (rnp->boost_kthread_task != NULL) - return 0; + return; t = kthread_create(rcu_boost_kthread, (void *)rnp, "rcub/%d", rnp_index); - if (IS_ERR(t)) - return PTR_ERR(t); + if (WARN_ON_ONCE(IS_ERR(t))) + return; raw_spin_lock_irqsave_rcu_node(rnp, flags); rnp->boost_kthread_task = t; raw_spin_unlock_irqrestore_rcu_node(rnp, flags); sp.sched_priority = kthread_prio; sched_setscheduler_nocheck(t, SCHED_FIFO, &sp); wake_up_process(t); /* get to TASK_INTERRUPTIBLE quickly. */ - return 0; } static void rcu_cpu_kthread_setup(unsigned int cpu) @@ -1265,7 +1264,7 @@ static void __init rcu_spawn_boost_kthreads(void) if (WARN_ONCE(smpboot_register_percpu_thread(&rcu_cpu_thread_spec), "%s: Could not start rcub kthread, OOM is now expected behavior\n", __func__)) return; rcu_for_each_leaf_node(rnp) - (void)rcu_spawn_one_boost_kthread(rnp); + rcu_spawn_one_boost_kthread(rnp); } static void rcu_prepare_kthreads(int cpu) @@ -1275,7 +1274,7 @@ static void rcu_prepare_kthreads(int cpu) /* Fire up the incoming CPU's kthread and leaf rcu_node kthread. */ if (rcu_scheduler_fully_active) - (void)rcu_spawn_one_boost_kthread(rnp); + rcu_spawn_one_boost_kthread(rnp); } #else /* #ifdef CONFIG_RCU_BOOST */ -- 1.9.1