Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751834AbcDUIj5 (ORCPT ); Thu, 21 Apr 2016 04:39:57 -0400 Received: from torres.zugschlus.de ([85.214.131.164]:60166 "EHLO torres.zugschlus.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751282AbcDUIjy (ORCPT ); Thu, 21 Apr 2016 04:39:54 -0400 Date: Thu, 21 Apr 2016 10:39:48 +0200 From: Marc Haber To: Paolo Bonzini Cc: Borislav Petkov , linux-kernel@vger.kernel.org, kvm ML Subject: Re: Major KVM issues with kernel 4.5 on the host Message-ID: <20160421083948.GF21755@torres.zugschlus.de> References: <20160317165435.GB3022@torres.zugschlus.de> <20160317181128.GA30324@pd.tnic> <56EBD20A.1020608@redhat.com> <20160413183701.GC7600@torres.zugschlus.de> <570EADD2.8030300@redhat.com> <20160413222942.GD7600@torres.zugschlus.de> <570EEF6D.40307@redhat.com> <20160414052220.GE7600@torres.zugschlus.de> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20160414052220.GE7600@torres.zugschlus.de> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2219 Lines: 47 On Thu, Apr 14, 2016 at 07:22:20AM +0200, Marc Haber wrote: > On Thu, Apr 14, 2016 at 03:16:29AM +0200, Paolo Bonzini wrote: > > On 14/04/2016 00:29, Marc Haber wrote: > > > On Wed, Apr 13, 2016 at 10:36:34PM +0200, Paolo Bonzini wrote: > > >> Didn't help, but a fresh look at the list of 4.5 patches helped. > > >> What the hell was I thinking, I missed write_rdtscp_aux who > > >> obviously uses MSR_TSC_AUX. > > > > > > I applied this patch to 4.5, which didn't go cleanly, I had to do it > > > manually, and there is no change in behavior. Sometimes, the Vm just > > > crashes, but most times the filesystem is remounted ro. > > > > Ok, then I guess bisection is needed. Please first try commit > > 45bdbcfdf241. If it fails, then the bug come together with KVM's merge > > window changes for 4.5-rc1. Please apply the patch I sent here when > > bisection is past 46896c73c1a4dde527c3a3cc43379deeb41985a1 (which means > > that probably that should be the commit you try second; the bisection > > then becomes much easier). > > I have never bisected this deeply. Can you please give more advice, > with which two commits to start? And how do I find out whether I am > "past" a commit? I am als not a git expert, a few command lines would > be appreciated. I have tried bisecting, and finally bisect says that the bad commit is 0e749e54244eec87b2a3cd0a4314e60bc6781115 dax: increase granularity of dax_clear_blocks() operations However, a kernel built after $ git checkout 0e749e54244eec87b2a3cd0a4314e60bc6781115 seems to be fine, at least my VM is running for 15 hours now. I guess I need to start over again with git bisect good 0e749e54244eec87b2a3cd0a4314e60bc6781115 and git bisect bad v4.5. Currently, I cannot explain how this has happened, I must have flagged an actually good kernel as bad from my understanding of git bisect. Can you give advice how to continue here? Greetings Marc -- ----------------------------------------------------------------------------- Marc Haber | "I don't trust Computers. They | Mailadresse im Header Leimen, Germany | lose things." Winona Ryder | Fon: *49 6224 1600402 Nordisch by Nature | How to make an American Quilt | Fax: *49 6224 1600421