From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752063AbdGYTTi (ORCPT ); Tue, 25 Jul 2017 15:19:38 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:47200 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751196AbdGYTTe (ORCPT ); Tue, 25 Jul 2017 15:19:34 -0400 Date: Tue, 25 Jul 2017 12:19:23 -0700 From: "Paul E. McKenney" To: Steven Rostedt Cc: linux-kernel@vger.kernel.org, mingo@kernel.org, jiangshanlai@gmail.com, dipankar@in.ibm.com, akpm@linux-foundation.org, mathieu.desnoyers@efficios.com, josh@joshtriplett.org, tglx@linutronix.de, peterz@infradead.org, dhowells@redhat.com, edumazet@google.com, fweisbec@gmail.com, oleg@redhat.com Subject: Re: [PATCH tip/core/rcu 03/15] rcu: Drive TASKS_RCU directly off of PREEMPT Reply-To: paulmck@linux.vnet.ibm.com References: <20170724214425.GA9665@linux.vnet.ibm.com> <1500932684-10469-3-git-send-email-paulmck@linux.vnet.ibm.com> <20170725141405.21979f48@vmware.local.home> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20170725141405.21979f48@vmware.local.home> User-Agent: Mutt/1.5.21 (2010-09-15) X-TM-AS-GCONF: 00 x-cbid: 17072519-0056-0000-0000-000003AC8EBC X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00007424; HX=3.00000241; KW=3.00000007; PH=3.00000004; SC=3.00000214; SDB=6.00892804; UDB=6.00446281; IPR=6.00672968; BA=6.00005492; NDR=6.00000001; ZLA=6.00000005; ZF=6.00000009; ZB=6.00000000; ZP=6.00000000; ZH=6.00000000; ZU=6.00000002; MB=3.00016375; XFM=3.00000015; UTC=2017-07-25 19:19:26 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 17072519-0057-0000-0000-000007E2ACB5 Message-Id: <20170725191923.GV3730@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:,, definitions=2017-07-25_08:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 suspectscore=0 malwarescore=0 phishscore=0 adultscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1706020000 definitions=main-1707250300 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jul 25, 2017 at 02:14:05PM -0400, Steven Rostedt wrote: > On Mon, 24 Jul 2017 14:44:32 -0700 > "Paul E. McKenney" wrote: > > > The actual use of TASKS_RCU is only when PREEMPT, otherwise RCU-sched > > is used instead. This commit therefore makes synchronize_rcu_tasks() > > and call_rcu_tasks() available always, but mapped to synchronize_sched() > > and call_rcu_sched(), respectively, when !PREEMPT. This approach also > > allows some #ifdefs to be removed from rcutorture. > > Hmm, I'll need to update ftrace. I believe I call synchronize_sched() > twice with !PREEMPT then. Does this mean that synchronize_rcu_tasks() should invoke synchronize_sched() twice? Easy change to make, if so. Thanx, Paul