From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751839AbdG0Oql (ORCPT ); Thu, 27 Jul 2017 10:46:41 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:47451 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751446AbdG0Oqk (ORCPT ); Thu, 27 Jul 2017 10:46:40 -0400 Date: Thu, 27 Jul 2017 07:46:34 -0700 From: "Paul E. McKenney" To: Peter Zijlstra 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, rostedt@goodmis.org, dhowells@redhat.com, edumazet@google.com, fweisbec@gmail.com, oleg@redhat.com, will.deacon@arm.com Subject: Re: [PATCH tip/core/rcu 4/5] sys_membarrier: Add expedited option Reply-To: paulmck@linux.vnet.ibm.com References: <20170725211926.GA3730@linux.vnet.ibm.com> <20170725215510.GD28975@worktop> <20170725235936.GC3730@linux.vnet.ibm.com> <20170726074128.ybb3e4flnjkrpi74@hirez.programming.kicks-ass.net> <20170726154110.GN3730@linux.vnet.ibm.com> <20170727083003.ivb2fr47vepa2g6t@hirez.programming.kicks-ass.net> <20170727130816.GP3730@linux.vnet.ibm.com> <20170727134908.6jiv6rm4tetmrapi@hirez.programming.kicks-ass.net> <20170727143205.GU3730@linux.vnet.ibm.com> <20170727143624.oghezky7owivouy7@hirez.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20170727143624.oghezky7owivouy7@hirez.programming.kicks-ass.net> User-Agent: Mutt/1.5.21 (2010-09-15) X-TM-AS-GCONF: 00 x-cbid: 17072714-0056-0000-0000-000003AD8E0F X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00007435; HX=3.00000241; KW=3.00000007; PH=3.00000004; SC=3.00000214; SDB=6.00893673; UDB=6.00446802; IPR=6.00673833; 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=3.00016409; XFM=3.00000015; UTC=2017-07-27 14:46:37 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 17072714-0057-0000-0000-000007E3ADDC Message-Id: <20170727144634.GY3730@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:,, definitions=2017-07-27_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-1707270231 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jul 27, 2017 at 04:36:24PM +0200, Peter Zijlstra wrote: > On Thu, Jul 27, 2017 at 07:32:05AM -0700, Paul E. McKenney wrote: > > > as per your proposed patch, will spray IPIs to all CPUs and at high > > > rates. > > > > OK, I have updated my patch to do throttling. > > But not respect cpusets. Which is the other important point. > > The scheduler based IPIs are limited to where we are allowed to place > tasks (as are the TLB ones for that matter, for the exact same reason). Yes, these are disadvantages, no argument there. But I will nevertheless be carrying some variant of this patch until something better exists, including that something being tested and found satisfactory by the various people asking for this. Thanx, Paul