From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751676AbdG0Rd7 (ORCPT ); Thu, 27 Jul 2017 13:33:59 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:42796 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751452AbdG0Rd5 (ORCPT ); Thu, 27 Jul 2017 13:33:57 -0400 Date: Thu, 27 Jul 2017 10:33:51 -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 02/15] rcu: Use timer as backstop for NOCB deferred wakeups Reply-To: paulmck@linux.vnet.ibm.com References: <20170724214425.GA9665@linux.vnet.ibm.com> <1500932684-10469-2-git-send-email-paulmck@linux.vnet.ibm.com> <20170725141220.4d2d968e@vmware.local.home> <20170725191814.GU3730@linux.vnet.ibm.com> <20170725181710.44cd1002@vmware.local.home> <20170726000540.GE3730@linux.vnet.ibm.com> <20170726171801.5da044c3@vmware.local.home> <20170726214741.GD3730@linux.vnet.ibm.com> <20170726190934.1807e761@vmware.local.home> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20170726190934.1807e761@vmware.local.home> User-Agent: Mutt/1.5.21 (2010-09-15) X-TM-AS-GCONF: 00 x-cbid: 17072717-0040-0000-0000-000003869DE7 X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00007436; HX=3.00000241; KW=3.00000007; PH=3.00000004; SC=3.00000214; SDB=6.00893729; UDB=6.00446835; IPR=6.00673889; BA=6.00005495; NDR=6.00000001; ZLA=6.00000005; ZF=6.00000009; ZB=6.00000000; ZP=6.00000000; ZH=6.00000000; ZU=6.00000002; MB=3.00016410; XFM=3.00000015; UTC=2017-07-27 17:33:54 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 17072717-0041-0000-0000-0000077ABDFB Message-Id: <20170727173351.GF3730@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:,, definitions=2017-07-27_10:,, 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-1707270274 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jul 26, 2017 at 07:09:34PM -0400, Steven Rostedt wrote: > On Wed, 26 Jul 2017 14:47:41 -0700 > "Paul E. McKenney" wrote: > > > > > It is much lighter weight than a timer setup. > > > > How much lighter weight? In other words, what fraction of the > > timers have to avoid being cancelled for irq_work to break even? > > No idea. I guess that would be a nice academic exercise ;-) Hmmm... I guess I should try it and see what it does, though that would be some merge window after the upcoming one. If it is indeed simpler, I might forgive some possible performance shortcomings... Thanx, Paul