From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754063Ab0AMB5A (ORCPT ); Tue, 12 Jan 2010 20:57:00 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753170Ab0AMB47 (ORCPT ); Tue, 12 Jan 2010 20:56:59 -0500 Received: from hera.kernel.org ([140.211.167.34]:42713 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753159Ab0AMB47 (ORCPT ); Tue, 12 Jan 2010 20:56:59 -0500 Message-ID: <4B4D2811.7000001@kernel.org> Date: Tue, 12 Jan 2010 17:55:29 -0800 From: Yinghai Lu User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.5) Gecko/20091130 SUSE/3.0.0-1.1.1 Thunderbird/3.0 MIME-Version: 1.0 To: Suresh Siddha CC: Linus Torvalds , "ananth@in.ibm.com" , Ingo Molnar , Thomas Gleixner , "H. Peter Anvin" , Andrew Morton , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH -v2 5/5] x86: use dmi check to treat disabled cpus as hotplug cpus. References: <1263338274-6485-1-git-send-email-yinghai@kernel.org> <1263338274-6485-5-git-send-email-yinghai@kernel.org> <1263340563.2854.1011.camel@sbs-t61.sc.intel.com> <4B4D0E39.10200@kernel.org> <1263347315.2854.1296.camel@sbs-t61.sc.intel.com> In-Reply-To: <1263347315.2854.1296.camel@sbs-t61.sc.intel.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 01/12/2010 05:48 PM, Suresh Siddha wrote: > On Tue, 2010-01-12 at 16:05 -0800, Yinghai Lu wrote: >> On 01/12/2010 03:56 PM, Suresh Siddha wrote: >>> On Tue, 2010-01-12 at 15:17 -0800, Yinghai Lu wrote: >>>> some systems that have disable cpus entries because same >>>> BIOS will support 2 sockets and 4 sockets and more at >>>> same time, BIOS just leave some disable entries, but >>>> those system do not support cpu hotplug. we don't need >>>> treat disabled_cpus as hotplug cpus. >>>> so we can make nr_cpu_ids smaller and save more space >>>> (pcpu data allocations), and could make some systems run >>>> with logical flat instead of physical flat apic mode >>>> >>>> -v2: change to black list instead >>> >>> I don't think this list will work because every HT system with HT >>> disabled in the bios shows that logical cpu as disabled. >> >> so you want to treat those disabled cpus in the those system as hotplug cpus or not? > > They are really not hot plug cpus, so they can also take advantage of > what you are trying to provide with this patch. you mean this blacklist could be too long? switch to whitelist for the box can treat disabled cpus as hotplug cpus? > > Also I am very confused with what exactly you are doing with the dmi > list.. > > + printk(KERN_NOTICE "%s detected: treat disabled cpus as hotplug ones\n", d->ident); > + treat_disabled_cpus_as_hotplug = 0; > sorry, forget to change the print out. YH