From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx118.postini.com [74.125.245.118]) by kanga.kvack.org (Postfix) with SMTP id 93B836B0081 for ; Fri, 30 Nov 2012 05:19:52 -0500 (EST) Message-ID: <50B88835.80805@parallels.com> Date: Fri, 30 Nov 2012 14:19:33 +0400 From: Glauber Costa MIME-Version: 1.0 Subject: Re: [PATCH v2 0/5] Add movablecore_map boot option 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> <3908561D78D1C84285E8C5FCA982C28F1C95FF53@ORSMSX108.amr.corp.intel.com> In-Reply-To: <3908561D78D1C84285E8C5FCA982C28F1C95FF53@ORSMSX108.amr.corp.intel.com> Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: "Luck, Tony" Cc: Mel Gorman , "H. Peter Anvin" , 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" On 11/30/2012 06:58 AM, Luck, Tony wrote: >> 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. > Which is a perfectly common workload for containers, where you can have hundreds of machines (per node) being sold out to third parties, a lot of them consuming every single bit of metadata they can. -- 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