From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S936061AbaH0W5q (ORCPT ); Wed, 27 Aug 2014 18:57:46 -0400 Received: from mail-wi0-f175.google.com ([209.85.212.175]:56142 "EHLO mail-wi0-f175.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S935948AbaH0W5p (ORCPT ); Wed, 27 Aug 2014 18:57:45 -0400 Date: Wed, 27 Aug 2014 23:57:39 +0100 From: Sitsofe Wheeler To: KY Srinivasan Cc: Dexuan Cui , Greg Kroah-Hartman , Haiyang Zhang , "devel@linuxdriverproject.org" , "linux-kernel@vger.kernel.org" Subject: Re: [PANIC, hyperv] BUG: unable to handle kernel paging request at ffff880077800004 (hv_ringbuffer_write) Message-ID: <20140827225739.GA24590@sucs.org> References: <20140820092630.GA1478@sucs.org> <20140825174132.GA17681@sucs.org> <20140827104408.GC1827@sucs.org> <20140827121559.GA14286@sucs.org> <20140827161900.GA25326@sucs.org> <51ae44fcae424365a6d78f3597175d77@BY2PR0301MB0711.namprd03.prod.outlook.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <51ae44fcae424365a6d78f3597175d77@BY2PR0301MB0711.namprd03.prod.outlook.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Aug 27, 2014 at 06:45:55PM +0000, KY Srinivasan wrote: > > > -----Original Message----- > > From: Sitsofe Wheeler [mailto:sitsofe@gmail.com] > > Sent: Wednesday, August 27, 2014 9:19 AM > > > > > BTW, with the patch below, hyperv_fb can work now, BUT, > > > *occasionally*, > > > storvsc_probe() -> ... -> vmbus_open() -> can fail due to > > > HV_STATUS_INVALID_ALIGNMENT... > > > > I applied your new patch on top of KY's pieces (it applied cleanly) > > and while it doesn't blow up, one warning is printed out and the UP > > boot seemed to stall after input: TPPS/2 message (but pressing > > ctrl-alt-delete allows the system to reboot cleanly). > > First let me thank you guys for looking into this issue. Looking at > your dmesg, it looked like storvsc probe failed as Dexuan had seen. > Since the failure appears to be alignment related, perhaps we could > test with allocating a page all the time (and getting rid of the > kmalloc). Sitsofe, here is a patch based on Dexuan's patch. If this > works, I will probably minimize failure cases by pre-allocating > per-cpu pages for this.: After some modifications to apply on top of your previous patches applying this latest patch has cured the issues surrounding hyperv_fb issues on boot. The only issue seen on boot now is similar to https://lkml.org/lkml/2014/8/19/227 ... How come previous alignment efforts weren't working out? -- Sitsofe | http://sucs.org/~sits/