From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from root by ciao.gmane.org with local (Exim 4.43) id 1Kx1NS-0006fD-EQ for linux-mm@kvack.org; Mon, 03 Nov 2008 15:30:02 +0000 Received: from one.firstfloor.org ([213.235.205.2]) by main.gmane.org with esmtp (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Mon, 03 Nov 2008 15:30:02 +0000 Received: from andi by one.firstfloor.org with local (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Mon, 03 Nov 2008 15:30:02 +0000 From: Andi Kleen Subject: Re: [PATCH] [RESEND] x86: add memory hotremove config option Date: 03 Nov 2008 16:22:27 +0100 Message-ID: References: <20081031175203.GA7483@us.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: owner-linux-mm@kvack.org Return-Path: To: linux-mm@kvack.org Cc: linux-kernel@vger.kernel.org List-ID: Gary Hade writes: > > Memory hotremove functionality can currently be configured into > the ia64, powerpc, and s390 kernels. This patch makes it possible > to configure the memory hotremove functionality into the x86 > kernel as well. You still didn't say how this is actually going to work and what it is good for? See thread last time. The big difference is that the powerpc and s390 kernels have the needed Hypervisor interfaces, x86 has not (not sure about ia64) iirc the code is useless for hardware based memory hotplug (because it doesn't free full nodes) and not useful for hypervisor based memory hotplug without additional drivers (and actual hypervisor support of course) Enabling the sysfs interface now is just giving a promise to the user that you cannot hold. Also it makes the kernel bigger without actually giving useful functionality. If some x86 hypervisor gains support for this I think the interface shouldn't be through sysfs, but controlled through the respective PV drivers which need to be involved anyways. -Andi -- ak@linux.intel.com -- 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