Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750936AbVKDVj3 (ORCPT ); Fri, 4 Nov 2005 16:39:29 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750937AbVKDVj3 (ORCPT ); Fri, 4 Nov 2005 16:39:29 -0500 Received: from smtp.osdl.org ([65.172.181.4]:64185 "EHLO smtp.osdl.org") by vger.kernel.org with ESMTP id S1750934AbVKDVj2 (ORCPT ); Fri, 4 Nov 2005 16:39:28 -0500 Date: Fri, 4 Nov 2005 13:39:06 -0800 (PST) From: Linus Torvalds To: Andy Nelson cc: mingo@elte.hu, akpm@osdl.org, arjan@infradead.org, arjanv@infradead.org, haveblue@us.ibm.com, kravetz@us.ibm.com, lhms-devel@lists.sourceforge.net, linux-kernel@vger.kernel.org, linux-mm@kvack.org, mbligh@mbligh.org, mel@csn.ul.ie, nickpiggin@yahoo.com.au Subject: Re: [Lhms-devel] [PATCH 0/7] Fragmentation Avoidance V19 In-Reply-To: Message-ID: References: <20051104210418.BC56F184739@thermo.lanl.gov> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1436 Lines: 33 On Fri, 4 Nov 2005, Linus Torvalds wrote: > > But the hint can be pretty friendly. Especially if it's an option to just > load a lot of memory into the boxes, and none of the loads are expected to > want to really be excessively close to memory limits (ie you could just > buy an extra 16GB to allow for "slop"). One of the issues _will_ be how to allocate things on NUMA. Right now "hugetlb" only allows us to say "this much memory for hugetlb", and it probably needs to be per-zone. Some uses might want to allocate all of the local memory on one node to huge-page usage (and specialized programs would then also like to run pinned to that node), others migth want to spread it out. So the maintenance would need to decide that. The good news is that you can boot up with almost all zones being "big page" zones, and you could turn them into "normal zones" dynamically. It's only going the other way that is hard. So from a maintenance standpoint if you manage lots of machines, you could have them all uniformly boot up with lots of memory set aside for large pages, and then use user-space tools to individually turn the zones into regular allocation zones. Linus - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/