From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754297Ab2ALQm1 (ORCPT ); Thu, 12 Jan 2012 11:42:27 -0500 Received: from rcsinet15.oracle.com ([148.87.113.117]:49536 "EHLO rcsinet15.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751514Ab2ALQmY (ORCPT ); Thu, 12 Jan 2012 11:42:24 -0500 Date: Thu, 12 Jan 2012 11:40:25 -0500 From: Konrad Rzeszutek Wilk To: Kay Sievers Cc: Sander Eikelenboom , linux-kernel@vger.kernel.org, xen-devel Subject: Re: linux 3.3-pre-rc1: Starting domU fails with Error: Failed to query current memory allocation of dom0. Message-ID: <20120112164025.GA22773@phenom.dumpdata.com> References: <498097597.20120112133832@eikelenboom.it> <20120112154613.GA10148@phenom.dumpdata.com> <20120112161204.GC10269@phenom.dumpdata.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20120112161204.GC10269@phenom.dumpdata.com> User-Agent: Mutt/1.5.21 (2010-09-15) X-Source-IP: acsinet22.oracle.com [141.146.126.238] X-Auth-Type: Internal IP X-CT-RefId: str=0001.0A090201.4F0F0D6C.0032,ss=1,re=0.000,fgs=0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jan 12, 2012 at 11:12:04AM -0500, Konrad Rzeszutek Wilk wrote: > On Thu, Jan 12, 2012 at 05:05:34PM +0100, Kay Sievers wrote: > > On Thu, Jan 12, 2012 at 16:46, Konrad Rzeszutek Wilk > > wrote: > > > On Thu, Jan 12, 2012 at 01:38:32PM +0100, Sander Eikelenboom wrote: > > > > >> Today i tried linuses tree of today (last commit is 4c4d285ad5665bfbd983b95fde8d7a477d24a361). > > >> > > >> It boots dom0 fine, but it fails to start any domU with: "Error: Failed to query current memory allocation of dom0." > > >> With my previous 3.1.5 kernel everything is fine, nothing else changed in config in between. > > > Your patch that converts the xen-balloon to use the regular device bus driver > > > (070680218379e15c1901f4bf21b98e3cbf12b527) has some not-so-happy consequences. > > > > > > The toolstack (xen-tools) use: > > > > > > /sys/devices/system/xen_memory/xen_memory0 > > > > > > But with the change, it is now: > > > > > > /sys/devices/xen_memory0/target_kb > > > > Urks, seems like a mistake on my side. > > > > Please try if changing: > > bus_unregister(&balloon_subsys); > > to: > > subsys_system_register(&balloon_subsys, NULL); > > in: > > drivers/xen/xen-balloon.c > > fixes the issue. > > Heh. I was *just* looking at d369a5d8fc70710236ae2d06a0e42dce483712df > ("clocksource: convert sysdev_class to a regular subsystem") and typed up this patch > to try it out: Kay, are you Acking this patch? (I can send it to Linus for rc0 or rc1) commit 4e6f161986678a25c9e76af98df928408c734a27 Author: Konrad Rzeszutek Wilk Date: Thu Jan 12 11:35:50 2012 -0500 xen/balloon: Move the registration from device to subsystem. With git commit 070680218379e15c1901f4bf21b98e3cbf12b527 "xen-balloon: convert sysdev_class to a regular subsystem" we would end up with the attributes being put in: /sys/devices/xen_memory0/target_kb instead of /sys/devices/system/xen_memory/xen_memory0/target_kb Making the tools unable to deflate the kernel to make more space for launching another guest and printing: Error: Failed to query current memory allocation of dom0 Reported-by: Sander Eikelenboom Suggested-by: Kay Sievers Signed-off-by: Konrad Rzeszutek Wilk diff --git a/drivers/xen/xen-balloon.c b/drivers/xen/xen-balloon.c index 3832e30..596e6a7 100644 --- a/drivers/xen/xen-balloon.c +++ b/drivers/xen/xen-balloon.c @@ -221,7 +221,7 @@ static int register_balloon(struct device *dev) { int i, error; - error = bus_register(&balloon_subsys); + error = subsys_system_register(&balloon_subsys, NULL); if (error) return error;