From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750715AbdD0Fct (ORCPT ); Thu, 27 Apr 2017 01:32:49 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:58912 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1161945AbdD0Fce (ORCPT ); Thu, 27 Apr 2017 01:32:34 -0400 Date: Wed, 26 Apr 2017 22:32:28 -0700 From: "Paul E. McKenney" To: Mike Galbraith Cc: LKML Subject: Re: TREE_SRCU slows hotplug by factor ~16 Reply-To: paulmck@linux.vnet.ibm.com References: <1493220380.6176.2.camel@gmx.de> <20170426154402.GT3956@linux.vnet.ibm.com> <1493221799.6176.5.camel@gmx.de> <1493228757.4132.2.camel@gmx.de> <20170426175544.GW3956@linux.vnet.ibm.com> <20170426175610.GA6491@linux.vnet.ibm.com> <1493230330.4132.4.camel@gmx.de> <1493264639.4154.10.camel@gmx.de> <20170427041136.GA3956@linux.vnet.ibm.com> <1493266556.4154.11.camel@gmx.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1493266556.4154.11.camel@gmx.de> User-Agent: Mutt/1.5.21 (2010-09-15) X-TM-AS-GCONF: 00 x-cbid: 17042705-0040-0000-0000-00000327E24A X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00006981; HX=3.00000240; KW=3.00000007; PH=3.00000004; SC=3.00000208; SDB=6.00853057; UDB=6.00421732; IPR=6.00631893; BA=6.00005313; NDR=6.00000001; ZLA=6.00000005; ZF=6.00000009; ZB=6.00000000; ZP=6.00000000; ZH=6.00000000; ZU=6.00000002; MB=3.00015201; XFM=3.00000013; UTC=2017-04-27 05:32:30 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 17042705-0041-0000-0000-0000071BFCB3 Message-Id: <20170427053228.GA11107@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:,, definitions=2017-04-27_05:,, 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=8.0.1-1703280000 definitions=main-1704270089 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Apr 27, 2017 at 06:15:56AM +0200, Mike Galbraith wrote: > On Wed, 2017-04-26 at 21:11 -0700, Paul E. McKenney wrote: > > > This is with srcutree.exp_holdoff set to 25*1000? > > Yup. And please see below for the trivial patch, just for confirmation. May I add your Tested-by? Thanx, Paul ------------------------------------------------------------------------ diff --git a/kernel/rcu/srcutree.c b/kernel/rcu/srcutree.c index ccbe1fb84165..65f03bca5b32 100644 --- a/kernel/rcu/srcutree.c +++ b/kernel/rcu/srcutree.c @@ -39,7 +39,7 @@ #include "rcu.h" -ulong exp_holdoff = 50 * 1000; /* Holdoff (ns) for auto-expediting. */ +ulong exp_holdoff = 25 * 1000; /* Holdoff (ns) for auto-expediting. */ module_param(exp_holdoff, ulong, 0444); static void srcu_invoke_callbacks(struct work_struct *work);