Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933375AbaGURmG (ORCPT ); Mon, 21 Jul 2014 13:42:06 -0400 Received: from mail-vc0-f176.google.com ([209.85.220.176]:33756 "EHLO mail-vc0-f176.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933261AbaGURmD (ORCPT ); Mon, 21 Jul 2014 13:42:03 -0400 MIME-Version: 1.0 In-Reply-To: <20140721172331.GB4156@linux.vnet.ibm.com> References: <1405064267-11678-1-git-send-email-jiang.liu@linux.intel.com> <20140721172331.GB4156@linux.vnet.ibm.com> Date: Mon, 21 Jul 2014 10:41:59 -0700 Message-ID: Subject: Re: [RFC Patch V1 00/30] Enable memoryless node on x86 platforms From: Tony Luck To: Nishanth Aravamudan Cc: Jiang Liu , Andrew Morton , Mel Gorman , David Rientjes , Mike Galbraith , Peter Zijlstra , "Rafael J . Wysocki" , "linux-mm@kvack.org" , linux-hotplug@vger.kernel.org, Linux Kernel Mailing List Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jul 21, 2014 at 10:23 AM, Nishanth Aravamudan wrote: > It seems like the issue is the order of onlining of resources on a > specific x86 platform? Yes. When we online a node the BIOS hits us with some ACPI hotplug events: First: Here are some new cpus Next: Here is some new memory Last; Here are some new I/O things (PCIe root ports, PCIe devices, IOAPICs, IOMMUs, ...) So there is a period where the node is memoryless - although that will generally be resolved when the memory hot plug event arrives ... that isn't guaranteed to occur (there might not be any memory on the node, or what memory there is may have failed self-test and been disabled). -Tony -- 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/