Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757295Ab3DXQ5B (ORCPT ); Wed, 24 Apr 2013 12:57:01 -0400 Received: from relay3.sgi.com ([192.48.152.1]:49617 "EHLO relay.sgi.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1756574Ab3DXQ5A (ORCPT ); Wed, 24 Apr 2013 12:57:00 -0400 Message-ID: <51780EDA.3000003@sgi.com> Date: Wed, 24 Apr 2013 09:56:58 -0700 From: Mike Travis User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:17.0) Gecko/20130307 Thunderbird/17.0.4 MIME-Version: 1.0 To: Bjorn Helgaas CC: Bian LuLu , "linux-kernel@vger.kernel.org" , "linux-pci@vger.kernel.org" Subject: Re: [RFC] The meaning of local_cpulist and local_cpus References: In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1578 Lines: 44 On 4/24/2013 9:48 AM, Bjorn Helgaas wrote: > [+cc linux-pci, Mike] > > On Wed, Apr 24, 2013 at 4:06 AM, Bian LuLu wrote: >> Hi all, >> >> Recently, i read some codes of PCI portions. I think >> local_cpulist is a list about one kind of CPU and >> local_cpus is a mask of CPU. But i am not sure when >> and how i should use these two parameters. >> >> See http://lxr.linux.no/linux+v3.5.4/drivers/pci/pci-sysfs.c#L390 for >> details. >> >> Would anyone please give me some suggestions? >> Thanks in advance ;-) > > I don't know off-hand, but maybe Mike or somebody on linux-pci does. > It looks like Mike added local_cpulist with 39106dcf85. > It primarily comes into play when you have a large # of cpus. Here's the difference on a system that has 1024 cpu threads: harp31-sys:/sys/devices/system/node/node20 # cat cpulist 160-167,672-679 harp31-sys:/sys/devices/system/node/node20 # cat cpumap 00000000,00000000,00000000,00000000,00000000,00000000,00000000, 00000000,00000000,00000000,000000ff,00000000,00000000,00000000, 00000000,00000000,00000000,00000000,00000000,00000000,00000000, 00000000,00000000,00000000,00000000,00000000,000000ff,00000000, 00000000,00000000,00000000,00000000 Which is easier to interpret? :) But there are some older user side utilities that still use the mask format. -- 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/