From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tejun Heo Subject: Re: [PATCH 20/21] x86, numa, acpi, memory-hotplug: Make movablecore=acpi have higher priority. Date: Tue, 23 Jul 2013 17:21:08 -0400 Message-ID: <20130723212108.GX21100@mtj.dyndns.org> References: <1374220774-29974-1-git-send-email-tangchen@cn.fujitsu.com> <1374220774-29974-21-git-send-email-tangchen@cn.fujitsu.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from mail-gg0-f171.google.com ([209.85.161.171]:40986 "EHLO mail-gg0-f171.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756516Ab3GWVVQ (ORCPT ); Tue, 23 Jul 2013 17:21:16 -0400 Content-Disposition: inline In-Reply-To: <1374220774-29974-21-git-send-email-tangchen@cn.fujitsu.com> Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org To: Tang Chen Cc: tglx@linutronix.de, mingo@elte.hu, hpa@zytor.com, akpm@linux-foundation.org, trenn@suse.de, yinghai@kernel.org, jiang.liu@huawei.com, wency@cn.fujitsu.com, laijs@cn.fujitsu.com, isimatu.yasuaki@jp.fujitsu.com, izumi.taku@jp.fujitsu.com, mgorman@suse.de, minchan@kernel.org, mina86@mina86.com, gong.chen@linux.intel.com, vasilis.liaskovitis@profitbricks.com, lwoodman@redhat.com, riel@redhat.com, jweiner@redhat.com, prarit@redhat.com, zhangyanfei@cn.fujitsu.com, yanghy@cn.fujitsu.com, x86@kernel.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-acpi@vger.kernel.org On Fri, Jul 19, 2013 at 03:59:33PM +0800, Tang Chen wrote: > Arrange hotpluggable memory as ZONE_MOVABLE will cause NUMA performance down > because the kernel cannot use movable memory. For users who don't use memory > hotplug and who don't want to lose their NUMA performance, they need a way to > disable this functionality. So we improved movablecore boot option. > > If users specify the original movablecore=nn@ss boot option, the kernel will > arrange [ss, ss+nn) as ZONE_MOVABLE. The kernelcore=nn@ss boot option is similar > except it specifies ZONE_NORMAL ranges. > > Now, if users specify "movablecore=acpi" in kernel commandline, the kernel will > arrange hotpluggable memory in SRAT as ZONE_MOVABLE. And if users do this, all > the other movablecore=nn@ss and kernelcore=nn@ss options should be ignored. > > For those who don't want this, just specify nothing. The kernel will act as > before. As I wrote before, I find movablecore=acpi rather weird. Shouldn't it be memory_hotplug enable/disable switch instead and movablecore, if specified, overriding information provided by firmware? Thanks. -- tejun