Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1030534AbWBIJwH (ORCPT ); Thu, 9 Feb 2006 04:52:07 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1030523AbWBIJwH (ORCPT ); Thu, 9 Feb 2006 04:52:07 -0500 Received: from fgwmail6.fujitsu.co.jp ([192.51.44.36]:54216 "EHLO fgwmail6.fujitsu.co.jp") by vger.kernel.org with ESMTP id S1030345AbWBIJwE (ORCPT ); Thu, 9 Feb 2006 04:52:04 -0500 Date: Thu, 09 Feb 2006 18:50:35 +0900 From: Yasunori Goto To: "Tolentino, Matthew E" , Andi Kleen Subject: Re: [RFC:PATCH(003/003)] Memory add to onlined node. (ver. 2) (For x86_64) Cc: "Brown, Len" , naveen.b.s@intel.com, Bjorn Helgaas , Linux Kernel ML , ACPI-ML , x86-64 Discuss , Linux Hotplug Memory Support In-Reply-To: <20060209153803.6CF4.Y-GOTO@jp.fujitsu.com> References: <20060209153803.6CF4.Y-GOTO@jp.fujitsu.com> X-Mailer-Plugin: BkASPil for Becky!2 Ver.2.063 Message-Id: <20060209164036.6CFC.Y-GOTO@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit X-Mailer: Becky! ver. 2.24.02 [ja] Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1234 Lines: 39 BTW, I have 2 question about x86_64's memory hot-add. Q1) > int add_memory(u64 start, u64 size) > { > - struct pglist_data *pgdat = NODE_DATA(0); > - struct zone *zone = pgdat->node_zones + MAX_NR_ZONES-2; Current code adds memory to ZONE_NORMAL like this. But, ZONE_DMA32 is available on 2.6.15. So, I'm afraid there are 2 types trouble. a) When new memory is added to < 4GB, this should be added to Zone_DMA32. Are there any real machine which allow to add memory under 4GB? b) If machine boots up with under 4GB memory, and new memory is added to over 4GB, then kernel might panic due to Zone Normal's initialization is imcomplete. Q2) Are there any real machine which can add memory with NUMA feature? Or will be there? In my patch, I assume that DSDT is defined well for NUMA by firmware. (Container device, Memory device...). But, if firmware doesn't define it, my patch is nonsense.. (Oh, I'm silly.....) -- Yasunori Goto - 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/