From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail137.messagelabs.com (mail137.messagelabs.com [216.82.249.19]) by kanga.kvack.org (Postfix) with ESMTP id 7E9AD6B00EE for ; Tue, 6 Sep 2011 07:34:51 -0400 (EDT) Received: by bkbzt4 with SMTP id zt4so6527481bkb.14 for ; Tue, 06 Sep 2011 04:34:47 -0700 (PDT) Date: Tue, 6 Sep 2011 13:36:06 +0200 From: Vasilis Liaskovitis Subject: Memory unplug question Message-ID: <20110906113606.GA6121@dhcp-192-168-178-175.profitbricks.localdomain> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Sender: owner-linux-mm@kvack.org List-ID: To: linux-mm@kvack.org Hi, I am trying to get memory-unplug to work on a kvm host/guest scenario. This is for an x86_64 kvm Linux guest running 3.1.0 kernel. The host is running a modified qemu-kvm and seabios to support memory hotplug (see https://patchwork.kernel.org/patch/1057612/ for details) I have managed to hotplug memory in 128MB chunks, above the 4GB limit. E.g. adding a 128MB memory range at 4GB physical offset results in the following dmesg output in the guest: [ 42.028288] Hotplug Mem Device [ 42.028580] init_memory_mapping: 0000000100000000-0000000108000000 [ 42.028633] 0100000000 - 0108000000 page 2M And the memory device can be onlined and normally used. On memory unplug, I always get the followings failure [ 71.907689] memory offlining 100000 to 108000 failed [ 71.908438] ACPI:memory_hp:Disable memory device (I have not onlined the memory device in the OS when trying the unplug) Specifically the callpath is: acpi_memory_disable_device() remove_memory() offline_pages() check_pages_isolated() returns a negative value. Is this expected behaviour? Can the pluggable memory pages be moved to a different memory zone so that they can be later isolated? I 've seen mention of ZONE_MOVABLE or a retry parameter in old memory-unplug patchsets. thanks for any suggestions, - Vasilis -- 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/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org