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=-8.5 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_SANE_1 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 B9E03C06511 for ; Tue, 2 Jul 2019 05:11:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9D0A821721 for ; Tue, 2 Jul 2019 05:11:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726970AbfGBFLy (ORCPT ); Tue, 2 Jul 2019 01:11:54 -0400 Received: from lgeamrelo12.lge.com ([156.147.23.52]:36069 "EHLO lgeamrelo11.lge.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1725775AbfGBFLy (ORCPT ); Tue, 2 Jul 2019 01:11:54 -0400 Received: from unknown (HELO lgeamrelo02.lge.com) (156.147.1.126) by 156.147.23.52 with ESMTP; 2 Jul 2019 14:11:49 +0900 X-Original-SENDERIP: 156.147.1.126 X-Original-MAILFROM: byungchul.park@lge.com Received: from unknown (HELO X58A-UD3R) (10.177.222.33) by 156.147.1.126 with ESMTP; 2 Jul 2019 14:11:49 +0900 X-Original-SENDERIP: 10.177.222.33 X-Original-MAILFROM: byungchul.park@lge.com Date: Tue, 2 Jul 2019 14:11:03 +0900 From: Byungchul Park To: "Paul E. McKenney" Cc: josh@joshtriplett.org, rostedt@goodmis.org, mathieu.desnoyers@efficios.com, jiangshanlai@gmail.com, joel@joelfernandes.org, rcu@vger.kernel.org, linux-kernel@vger.kernel.org, kernel-team@lge.com Subject: Re: [PATCH v3] rcu: Change return type of rcu_spawn_one_boost_kthread() Message-ID: <20190702051103.GA13132@X58A-UD3R> References: <1561941639-14318-1-git-send-email-byungchul.park@lge.com> <20190701201216.GQ26519@linux.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190701201216.GQ26519@linux.ibm.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jul 01, 2019 at 01:12:16PM -0700, Paul E. McKenney wrote: > On Mon, Jul 01, 2019 at 09:40:39AM +0900, Byungchul Park wrote: > > Hello, > > > > I tested again if the WARN_ON_ONCE() is fired with my box. > > > > And it was OK. > > > > Thanks, > > Byungchul > > And it now applies just fine, so I have queued it, thank you! > > In the future, could you please use something like "git send-email" > to email a proper patch? When you do it this way, after I do "git am", > I have to hand-edit the commit to remove this preamble. Oh! Sorry to hear that. I've been always using "git send-email" with scissors in the body expecting you do "git am -c". Do you mean it's not a good way, right? I won't use the scissors again. > But while I was doing the hand-editing, I updated the commit log as > follows: > > rcu: Change return type of rcu_spawn_one_boost_kthread() > > The return value of rcu_spawn_one_boost_kthread() is not used > any longer. This commit therefore changes its return type from > int to void, and removes the cast to void from its callers. > > Does that work for you? Sure. Thank you. Thanks, Byungchul > Thanx, Paul > > > Changes from v2 > > -. Port the patch to a1af11a24cb0 (Paul's request) > > -. Add a few new lines for a better look > > > > Changes from v1 > > -. WARN_ON_ONCE() on failing to create rcu_boost_kthread. > > -. Changed title and commit message a bit. > > > > ---8<--- > > >From 20c934c5657a7a0f13ebb050ffd350d4174965d0 Mon Sep 17 00:00:00 2001 > > From: Byungchul Park > > Date: Mon, 1 Jul 2019 09:27:15 +0900 > > Subject: [PATCH v3] 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 | 20 +++++++++++--------- > > 1 file changed, 11 insertions(+), 9 deletions(-) > > > > diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h > > index c588ef9..b8eea22 100644 > > --- a/kernel/rcu/tree_plugin.h > > +++ b/kernel/rcu/tree_plugin.h > > @@ -1119,7 +1119,7 @@ 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; > > @@ -1127,25 +1127,27 @@ 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; > > } > > > > /* > > @@ -1186,7 +1188,7 @@ static void __init rcu_spawn_boost_kthreads(void) > > struct rcu_node *rnp; > > > > 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) > > @@ -1196,7 +1198,7 @@ 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 > >