From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752094AbeEOETV (ORCPT ); Tue, 15 May 2018 00:19:21 -0400 Received: from lgeamrelo13.lge.com ([156.147.23.53]:37805 "EHLO lgeamrelo11.lge.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1750759AbeEOETU (ORCPT ); Tue, 15 May 2018 00:19:20 -0400 X-Original-SENDERIP: 156.147.1.127 X-Original-MAILFROM: byungchul.park@lge.com X-Original-SENDERIP: 10.177.220.135 X-Original-MAILFROM: byungchul.park@lge.com Subject: Re: [PATCH] rcu: Report a quiescent state of TASKS_RCU on a tick from user To: paulmck@linux.vnet.ibm.com Cc: jiangshanlai@gmail.com, josh@joshtriplett.org, rostedt@goodmis.org, mathieu.desnoyers@efficios.com, linux-kernel@vger.kernel.org, kernel-team@lge.com, joel@joelfernandes.org References: <1526344426-31836-1-git-send-email-byungchul.park@lge.com> <20180515041111.GC26088@linux.vnet.ibm.com> From: Byungchul Park Message-ID: <28cb032c-1c44-41b2-4703-e6f942d073de@lge.com> Date: Tue, 15 May 2018 13:19:17 +0900 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:52.0) Gecko/20100101 Thunderbird/52.7.0 MIME-Version: 1.0 In-Reply-To: <20180515041111.GC26088@linux.vnet.ibm.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2018-05-15 13:11, Paul E. McKenney wrote: > On Tue, May 15, 2018 at 09:33:46AM +0900, Byungchul Park wrote: >> Hello Paul, >> >> You removed the reporing while simplifying the commit 508880df6 :) >> Fold this patch onto the commit or add, whatever you want. > > First, thank you for checking! > > But second, the removal was intentional. Tiny RCU only exists in > PREEMPT=n kernels, and in such kernels there can be no RCU-tasks. > This is the reason for this line in the new commit log: I see. Thank you. > [ paulmck: Simplify rcutiny portion given no RCU-tasks for !PREEMPT. ] > > Thanx, Paul > >> Thanks, >> Byungchul >> >> ----->8----- >> >From 18a2d8da3baf79d0edd5ccf94abe6f989da5b1c1 Mon Sep 17 00:00:00 2001 >> From: Byungchul Park >> Date: Tue, 15 May 2018 09:21:43 +0900 >> Subject: [PATCH] rcu: Report a quiescent state of TASKS_RCU on a tick from >> user >> >> The reporting was removed while simplifying the commit 508880df6 (rcu: >> Improve rcu_note_voluntary_context_switch() reporting). Add it back. >> >> Signed-off-by: Byungchul Park >> --- >> kernel/rcu/tiny.c | 4 +++- >> 1 file changed, 3 insertions(+), 1 deletion(-) >> >> diff --git a/kernel/rcu/tiny.c b/kernel/rcu/tiny.c >> index befc932..3345596 100644 >> --- a/kernel/rcu/tiny.c >> +++ b/kernel/rcu/tiny.c >> @@ -120,8 +120,10 @@ void rcu_bh_qs(void) >> */ >> void rcu_check_callbacks(int user) >> { >> - if (user) >> + if (user) { >> rcu_sched_qs(); >> + rcu_tasks_qs(); >> + } >> if (user || !in_softirq()) >> rcu_bh_qs(); >> } >> -- >> 1.9.1 >> > > -- Thanks, Byungchul