Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753219AbbKIFsC (ORCPT ); Mon, 9 Nov 2015 00:48:02 -0500 Received: from aserp1040.oracle.com ([141.146.126.69]:18969 "EHLO aserp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752889AbbKIFq4 (ORCPT ); Mon, 9 Nov 2015 00:46:56 -0500 Reply-To: zhenzhong.duan@oracle.com Subject: Re: Question with maxcpus= parameter. References: <563C3980.8060405@oracle.com> <20151106161459.GB4538@char.us.oracle.com> To: Konrad Rzeszutek Wilk Cc: rusty@rustcorp.com.au, ashok.raj@intel.com, LKML , Feng Jin From: Zhenzhong Duan Organization: Oracle Message-ID: <56403368.60603@oracle.com> Date: Mon, 9 Nov 2015 13:47:20 +0800 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:38.0) Gecko/20100101 Thunderbird/38.3.0 MIME-Version: 1.0 In-Reply-To: <20151106161459.GB4538@char.us.oracle.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-Source-IP: userv0021.oracle.com [156.151.31.71] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1383 Lines: 39 Tried nr_cpus=4, works. [root@rwssq01 ~]# cat /sys/devices/system/cpu/possible 0-3 [root@rwssq01 ~]# cat /sys/devices/system/cpu/present 0-3 [root@rwssq01 ~]# uname -a Linux rwssq01.us.oracle.com 3.8.13-44.1.1.el6uek.x86_64 #2 SMP Wed Sep 10 06:10:25 PDT 2014 x86_64 x86_64 x86_64 GNU/Linux zduan 在 2015/11/7 0:14, Konrad Rzeszutek Wilk 写道: > On Fri, Nov 06, 2015 at 01:24:16PM +0800, Zhenzhong Duan wrote: >> Hi Maintainers, >> >> Recently we faced an cpu online issue with maxcpus= parameter. > Did you try 'nr_cpus' ? >> We want to have 4 cpus onlined at bootup, test 3.8.13-stable on an 72 cpus >> env with maxcpus=4, I found more cpus than 4 are onlined. >> It's the udev scripts make them onlined. But below script exist for a long >> time. >> ACTION=="add", KERNEL=="cpu[0-9]*", RUN+="/bin/bash -c 'echo 1 > >> /sys/devices/system/cpu/%k/online'" >> >> maxcpu= parameter didn't take effect, so is this a kernel bug? Or that >> script should be removed? >> >> Btw: 2.6.39 works fine, I checked udev log, seems CPU ADD event is only sent >> for 4cpus. >> Why the difference between 2.6.39 and 3.8.13? >> >> thanks >> zduan -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/