From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Vrabel Subject: Re: BUG: using smp_processor_id() in preemptible [00000000] code: blkback.1.xvdb/9138 caller is decrease_reservation Date: Wed, 11 Sep 2013 11:09:05 +0100 Message-ID: <52304141.7040309@citrix.com> References: <1323058712.20130910201353@eikelenboom.it> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from mail6.bemta14.messagelabs.com ([193.109.254.103]) by lists.xen.org with esmtp (Exim 4.72) (envelope-from ) id 1VJhMI-0005qj-DT for xen-devel@lists.xenproject.org; Wed, 11 Sep 2013 10:09:14 +0000 In-Reply-To: <1323058712.20130910201353@eikelenboom.it> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Sander Eikelenboom Cc: xen-devel , Stefano Stabellini , Wei Liu List-Id: xen-devel@lists.xenproject.org On 10/09/13 19:13, Sander Eikelenboom wrote: > Hi Wei, > > Just back from holiday i tried running a new xen-unstable and linux > kernel (current Linus his tree + Konrad's last pull request merged on top). > I saw a thread and patch about a bug_on in increase_reservation ... > i'm seeing the splat below in dom0 when guests get started. Yes, the use of __per_cpu() in decrease_reservation is not safe. Stefano, what testing did you give "xen/balloon: set a mapping for ballooned out pages" (cd9151e2). The number of critical problems it's had suggests not a lot? I'm also becoming less happy with the inconsistency between the p2m updates between the different (non-)auto_translated_physmap guest types. I think it (and all the attempts to fix it) should be reverted at this stage and we should try again for 3.13 which some more through testing and a more careful look at what updates to the p2m are needed. David