Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758673Ab3JNUv1 (ORCPT ); Mon, 14 Oct 2013 16:51:27 -0400 Received: from terminus.zytor.com ([198.137.202.10]:56989 "EHLO mail.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757423Ab3JNUtt (ORCPT ); Mon, 14 Oct 2013 16:49:49 -0400 Message-ID: <525C58D3.1060705@zytor.com> Date: Mon, 14 Oct 2013 13:49:23 -0700 From: "H. Peter Anvin" User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130625 Thunderbird/17.0.7 MIME-Version: 1.0 To: Yinghai Lu CC: Zhang Yanfei , Tejun Heo , Zhang Yanfei , Toshi Kani , Ingo Molnar , Andrew Morton , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH part2 v2 0/8] Arrange hotpluggable memory as ZONE_MOVABLE References: <5258E560.5050506@cn.fujitsu.com> <525B19C3.9040907@gmail.com> <20131014133835.GG4722@htj.dyndns.org> <525BFCF3.5010908@gmail.com> <20131014142719.GI4722@htj.dyndns.org> <525C02DC.4050706@gmail.com> <20131014145131.GJ4722@htj.dyndns.org> <525C0866.2010808@gmail.com> <20131014151902.GL4722@htj.dyndns.org> <525C0EFE.2010409@gmail.com> <525C55A6.1030406@zytor.com> In-Reply-To: X-Enigmail-Version: 1.5.2 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 826 Lines: 23 On 10/14/2013 01:42 PM, Yinghai Lu wrote: >> >> However, I don't understand how we can avoid #2, given that it is >> fundamentally a sysadmin-driven tradeoff between performance and >> reliability. > > If we make all numa systems support nodes hot-remove logically. > like we boot system with node0, and hot add other nodes one by one, > we should hot remove them later. > No, it doesn't work that way for memory. You can't do nonmovable allocations from a node that you may need to yank, unless you can migrate that memory node transparently (which hardware can do.) -hpa -- 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/