From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1164531AbdDXDdA (ORCPT ); Sun, 23 Apr 2017 23:33:00 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:54169 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1164470AbdDXDcw (ORCPT ); Sun, 23 Apr 2017 23:32:52 -0400 Date: Sun, 23 Apr 2017 20:32:50 -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: <1493002089.4145.7.camel@gmx.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1493002089.4145.7.camel@gmx.de> User-Agent: Mutt/1.5.21 (2010-09-15) X-TM-AS-GCONF: 00 x-cbid: 17042403-0024-0000-0000-000002538D8E X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00006963; HX=3.00000240; KW=3.00000007; PH=3.00000004; SC=3.00000208; SDB=6.00851625; UDB=6.00420844; IPR=6.00630417; BA=6.00005307; NDR=6.00000001; ZLA=6.00000005; ZF=6.00000009; ZB=6.00000000; ZP=6.00000000; ZH=6.00000000; ZU=6.00000002; MB=3.00015150; XFM=3.00000013; UTC=2017-04-24 03:32:49 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 17042403-0025-0000-0000-0000439B7D3C Message-Id: <20170424033250.GX3956@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:,, definitions=2017-04-24_02:,, 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-1704240051 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Apr 24, 2017 at 04:48:09AM +0200, Mike Galbraith wrote: > Greetings, > > Running Steven's hotplug stress script in tip w. CLASSIC_SRCU takes 55s > in my i4790 box, whereas TREE_SRCU takes over 16m. (Master with the > same config does it in 39s.. but then lockdep isn't enabled in master) That doesn't sound good... But exactly which version are you using? There were some 8x slowdowns earlier this week that have since been fixed. Also, how many CPUs are on your system? Thanx, Paul