From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail190.messagelabs.com (mail190.messagelabs.com [216.82.249.51]) by kanga.kvack.org (Postfix) with SMTP id B01546B010C for ; Wed, 13 Oct 2010 04:45:14 -0400 (EDT) Received: from m6.gw.fujitsu.co.jp ([10.0.50.76]) by fgwmail6.fujitsu.co.jp (Fujitsu Gateway) with ESMTP id o9D8jBR5018976 for (envelope-from kamezawa.hiroyu@jp.fujitsu.com); Wed, 13 Oct 2010 17:45:12 +0900 Received: from smail (m6 [127.0.0.1]) by outgoing.m6.gw.fujitsu.co.jp (Postfix) with ESMTP id 99F0345DE52 for ; Wed, 13 Oct 2010 17:45:11 +0900 (JST) Received: from s6.gw.fujitsu.co.jp (s6.gw.fujitsu.co.jp [10.0.50.96]) by m6.gw.fujitsu.co.jp (Postfix) with ESMTP id 7EE8645DD71 for ; Wed, 13 Oct 2010 17:45:11 +0900 (JST) Received: from s6.gw.fujitsu.co.jp (localhost.localdomain [127.0.0.1]) by s6.gw.fujitsu.co.jp (Postfix) with ESMTP id 680BC1DB8012 for ; Wed, 13 Oct 2010 17:45:11 +0900 (JST) Received: from ml13.s.css.fujitsu.com (ml13.s.css.fujitsu.com [10.249.87.103]) by s6.gw.fujitsu.co.jp (Postfix) with ESMTP id 1C328E38001 for ; Wed, 13 Oct 2010 17:45:11 +0900 (JST) Date: Wed, 13 Oct 2010 17:39:50 +0900 From: KAMEZAWA Hiroyuki Subject: Re: [RFC][PATCH 1/3] contigous big page allocator Message-Id: <20101013173950.0521c849.kamezawa.hiroyu@jp.fujitsu.com> In-Reply-To: <87ocay1obe.fsf@basil.nowhere.org> References: <20101013121527.8ec6a769.kamezawa.hiroyu@jp.fujitsu.com> <87sk0a1sq0.fsf@basil.nowhere.org> <20101013161206.c29df8ea.kamezawa.hiroyu@jp.fujitsu.com> <87ocay1obe.fsf@basil.nowhere.org> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org To: Andi Kleen Cc: "linux-mm@kvack.org" , "linux-kernel@vger.kernel.org" , "minchan.kim@gmail.com" , fujita.tomonori@lab.ntt.co.jp List-ID: On Wed, 13 Oct 2010 10:36:53 +0200 Andi Kleen wrote: > KAMEZAWA Hiroyuki writes: > > >> > My intention is not for allocating HUGEPAGE(> MAX_ORDER). > >> > >> I still believe using this for 1GB pages would be one of the more > >> interesting use cases. > >> > > > > I'm successfully allocating 1GB of continous pages at test. But I'm not sure > > requirements and users. How quick this allocation should be ? > > This will always be slow. Huge pages are always pre allocated > even today through a sysctl. The use case would be have > > echo XXX > /proc/sys/vm/nr_hugepages > > at runtime working for 1GB too, instead of requiring a reboot > for this. > > I think it's ok if that is somewhat slow, as long as it is not > incredible slow. Ideally it shouldn't cause a swap storm either > > (maybe we need some way to indicate how hard the freeing code should > try?) > yes. I think this patch should be update to do a precice control of memory pressure. It will improve memory hotplug's memory allocation, too. > I guess it would only really work well if you predefine > movable zones at boot time. > I think so, too. But maybe enough for embeded guys and very special systems which need to use 1G page. Thanks, -Kame -- 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