From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-yk0-f170.google.com (mail-yk0-f170.google.com [209.85.160.170]) by kanga.kvack.org (Postfix) with ESMTP id B7B2428027E for ; Wed, 15 Jul 2015 18:06:28 -0400 (EDT) Received: by ykeo3 with SMTP id o3so48846059yke.0 for ; Wed, 15 Jul 2015 15:06:28 -0700 (PDT) Received: from mail-yk0-x22e.google.com (mail-yk0-x22e.google.com. [2607:f8b0:4002:c07::22e]) by mx.google.com with ESMTPS id k184si4055887ywf.180.2015.07.15.15.06.27 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 15 Jul 2015 15:06:28 -0700 (PDT) Received: by ykay190 with SMTP id y190so48971032yka.3 for ; Wed, 15 Jul 2015 15:06:27 -0700 (PDT) Date: Wed, 15 Jul 2015 18:06:25 -0400 From: Tejun Heo Subject: Re: [PATCH 4/5] x86, acpi, cpu-hotplug: Enable MADT APIs to return disabled apicid. Message-ID: <20150715220625.GN15934@mtj.duckdns.org> References: <1436261425-29881-1-git-send-email-tangchen@cn.fujitsu.com> <1436261425-29881-5-git-send-email-tangchen@cn.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1436261425-29881-5-git-send-email-tangchen@cn.fujitsu.com> Sender: owner-linux-mm@kvack.org List-ID: To: Tang Chen Cc: mingo@redhat.com, akpm@linux-foundation.org, rjw@rjwysocki.net, hpa@zytor.com, laijs@cn.fujitsu.com, yasu.isimatu@gmail.com, isimatu.yasuaki@jp.fujitsu.com, kamezawa.hiroyu@jp.fujitsu.com, izumi.taku@jp.fujitsu.com, gongzhaogang@inspur.com, qiaonuohan@cn.fujitsu.com, x86@kernel.org, linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, Gu Zheng Hello, On Tue, Jul 07, 2015 at 05:30:24PM +0800, Tang Chen wrote: > From: Gu Zheng > > All processors' apicids can be obtained by _MAT method or from MADT in ACPI. > The current code ignores disabled processors and returns -ENODEV. > > After this patch, a new parameter will be added to MADT APIs so that caller > is able to control if disabled processors are ignored. This describes what the patch does but doesn't really explain what the patch is trying to achieve. > @@ -282,8 +282,11 @@ static int acpi_processor_get_info(struct acpi_device *device) > * Extra Processor objects may be enumerated on MP systems with > * less than the max # of CPUs. They should be ignored _iff > * they are physically not present. > + * > + * NOTE: Even if the processor has a cpuid, it may not present because ^ be > + * cpuid <-> apicid mapping is persistent now. Saying "now" is kinda weird as this is how the code is gonna be forever. Thanks. -- tejun -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org