From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755513Ab2K3C7S (ORCPT ); Thu, 29 Nov 2012 21:59:18 -0500 Received: from mga01.intel.com ([192.55.52.88]:28661 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754971Ab2K3C7Q convert rfc822-to-8bit (ORCPT ); Thu, 29 Nov 2012 21:59:16 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.84,189,1355126400"; d="scan'208";a="255362449" From: "Luck, Tony" To: Mel Gorman , "H. Peter Anvin" CC: Jiang Liu , Tang Chen , "akpm@linux-foundation.org" , "rob@landley.net" , "isimatu.yasuaki@jp.fujitsu.com" , "laijs@cn.fujitsu.com" , "wency@cn.fujitsu.com" , "linfeng@cn.fujitsu.com" , "yinghai@kernel.org" , "kosaki.motohiro@jp.fujitsu.com" , "minchan.kim@gmail.com" , "rientjes@google.com" , "rusty@rustcorp.com.au" , "linux-kernel@vger.kernel.org" , "linux-mm@kvack.org" , "linux-doc@vger.kernel.org" , Len Brown , "Wang, Frank" Subject: RE: [PATCH v2 0/5] Add movablecore_map boot option Thread-Topic: [PATCH v2 0/5] Add movablecore_map boot option Thread-Index: AQHNzUWLbzufafl3KEuH3pSKrF3YJJf/w9zAgACJM4CAAOARgIAAg2Yg Date: Fri, 30 Nov 2012 02:58:40 +0000 Message-ID: <3908561D78D1C84285E8C5FCA982C28F1C95FF53@ORSMSX108.amr.corp.intel.com> References: <1353667445-7593-1-git-send-email-tangchen@cn.fujitsu.com> <50B5CFAE.80103@huawei.com> <3908561D78D1C84285E8C5FCA982C28F1C95EDCE@ORSMSX108.amr.corp.intel.com> <50B68467.5020008@zytor.com> <20121129110045.GX8218@suse.de> In-Reply-To: <20121129110045.GX8218@suse.de> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [10.22.254.138] Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 8BIT MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > If any significant percentage of memory is in ZONE_MOVABLE then the memory > hotplug people will have to deal with all the lowmem/highmem problems > that used to be faced by 32-bit x86 with PAE enabled. While these problems may still exist on large systems - I think it becomes harder to construct workloads that run into problems. In those bad old days a significant fraction of lowmem was consumed by the kernel ... so it was pretty easy to find meta-data intensive workloads that would push it over a cliff. Here we are talking about systems with say 128GB per node divided into 64GB moveable and 64GB non-moveable (and I'd regard this as a rather low-end machine). Unless the workload consists of zillions of tiny processes all mapping shared memory blocks, the percentage of memory allocated to the kernel is going to be tiny compared with the old 4GB days. -Tony From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx145.postini.com [74.125.245.145]) by kanga.kvack.org (Postfix) with SMTP id 049396B0074 for ; Thu, 29 Nov 2012 21:59:04 -0500 (EST) From: "Luck, Tony" Subject: RE: [PATCH v2 0/5] Add movablecore_map boot option Date: Fri, 30 Nov 2012 02:58:40 +0000 Message-ID: <3908561D78D1C84285E8C5FCA982C28F1C95FF53@ORSMSX108.amr.corp.intel.com> References: <1353667445-7593-1-git-send-email-tangchen@cn.fujitsu.com> <50B5CFAE.80103@huawei.com> <3908561D78D1C84285E8C5FCA982C28F1C95EDCE@ORSMSX108.amr.corp.intel.com> <50B68467.5020008@zytor.com> <20121129110045.GX8218@suse.de> In-Reply-To: <20121129110045.GX8218@suse.de> Content-Language: en-US Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Sender: owner-linux-mm@kvack.org List-ID: To: Mel Gorman , "H. Peter Anvin" Cc: Jiang Liu , Tang Chen , "akpm@linux-foundation.org" , "rob@landley.net" , "isimatu.yasuaki@jp.fujitsu.com" , "laijs@cn.fujitsu.com" , "wency@cn.fujitsu.com" , "linfeng@cn.fujitsu.com" , "yinghai@kernel.org" , "kosaki.motohiro@jp.fujitsu.com" , "minchan.kim@gmail.com" , "rientjes@google.com" , "rusty@rustcorp.com.au" , "linux-kernel@vger.kernel.org" , "linux-mm@kvack.org" , "linux-doc@vger.kernel.org" , Len Brown , "Wang, Frank" > If any significant percentage of memory is in ZONE_MOVABLE then the memor= y > hotplug people will have to deal with all the lowmem/highmem problems > that used to be faced by 32-bit x86 with PAE enabled.=20 While these problems may still exist on large systems - I think it becomes harder to construct workloads that run into problems. In those bad old day= s a significant fraction of lowmem was consumed by the kernel ... so it was pretty easy to find meta-data intensive workloads that would push it over a cliff. Here we are talking about systems with say 128GB per node divide= d into 64GB moveable and 64GB non-moveable (and I'd regard this as a rather low-end machine). Unless the workload consists of zillions of tiny process= es all mapping shared memory blocks, the percentage of memory allocated to the kernel is going to be tiny compared with the old 4GB days. -Tony -- 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