From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-we0-f178.google.com (mail-we0-f178.google.com [74.125.82.178]) by kanga.kvack.org (Postfix) with ESMTP id 9581E6B0038 for ; Mon, 21 Jul 2014 16:06:33 -0400 (EDT) Received: by mail-we0-f178.google.com with SMTP id w61so8076227wes.23 for ; Mon, 21 Jul 2014 13:06:33 -0700 (PDT) Received: from casper.infradead.org (casper.infradead.org. [2001:770:15f::2]) by mx.google.com with ESMTPS id ef9si30233292wjd.148.2014.07.21.13.06.31 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 21 Jul 2014 13:06:32 -0700 (PDT) Date: Mon, 21 Jul 2014 22:06:25 +0200 From: Peter Zijlstra Subject: Re: [RFC Patch V1 00/30] Enable memoryless node on x86 platforms Message-ID: <20140721200625.GR3935@laptop> References: <1405064267-11678-1-git-send-email-jiang.liu@linux.intel.com> <20140721172331.GB4156@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: owner-linux-mm@kvack.org List-ID: To: Tony Luck Cc: Nishanth Aravamudan , Jiang Liu , Andrew Morton , Mel Gorman , David Rientjes , Mike Galbraith , "Rafael J . Wysocki" , "linux-mm@kvack.org" , linux-hotplug@vger.kernel.org, Linux Kernel Mailing List On Mon, Jul 21, 2014 at 10:41:59AM -0700, Tony Luck wrote: > 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). Right, but we could 'easily' capture that in arch code and make it look like it was done in a 'sane' order. No need to wreck the rest of the kernel to support this particular BIOS fuckup. -- 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