From mboxrd@z Thu Jan 1 00:00:00 1970 From: Carsten Emde Subject: Re: 2.6.23.1-rt4 and kvm 48 Date: Tue, 06 Nov 2007 10:53:54 +0100 Message-ID: <473039B2.1010106@osadl.org> References: <9c21eeae0710290709x527cf4fcq52bb410907ff496@mail.gmail.com> <47299C43.1070703@qumranet.com> <472F7CA7.8060707@osadl.org> <9c21eeae0711052122y483b06d8ycbcfbfb95fb36663@mail.gmail.com> <47302208.2090301@qumranet.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: kvm-devel-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org To: dor.laor-atKUWr5tajBWk0Htik3J/w@public.gmane.org Return-path: In-Reply-To: <47302208.2090301-atKUWr5tajBWk0Htik3J/w@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: kvm-devel-bounces-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org Errors-To: kvm-devel-bounces-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org List-Id: kvm.vger.kernel.org Dor, >>>> I tried to recreate your problem using 2.6.23-1 and latest rt patch >>>> (rt5). >>>> The problem is that the kernel is not stable at all, I can't even >>>> compile the code over vnc - >>>> my connection is constantly lost. So it might not be kvm problem? >>>> Can you try is with -no-kvm and see if it's working - then its just a >>>> regular userspace process. >>>> Anyway if all other things are stable on your end, can you send us >>>> dmesg/strace outputs? >>> Thanks, Dor, for offering help. >>> The most recent RT-Preempt patch (2.6.23.1-rt5) still has an SMP issue >>> which need to be sorted out first. >>> When a working RT-Preempt patch is available, I will be glad to send >>> dmesg outputs. We may then share our activities to create the next >>> "Latest stable" RT-Preempt kernel that includes kvm support. >> Wow, that smp issue may be a problem I've got a Intel Core 2 cpu with >> just 2 cores. >> but I've not seen a dump like this in a while (lustre?). We see this all the time when we try to run unmodified kvm in an rt-kernel, nothing special. >> I've updated to 2.6.23-rt5 and kvm-50 and I got this dump.... >> [..] >> BUG: scheduling while atomic: >> [..] >> This loops forever basically... >> I'm really confused about this one. I've got the full minicom.cap file >> from the session that produced this its attached zipped up. >> If you'd like any other information I'd be glad to post it. No, please not. Our log files are full of it. The "BUG: scheduling while atomic" problem is not related to the current SMP issue. It is the result of running rt-unaware code in an rt-kernel. > If the rt patch is not smp stable you can boot with single cpu and run > kvm there. > Maybe just pinning the guest to specific cpu will help although I had > troubles with X too. This does not fix the problem. Save your energy. We live with this situation since kvm-28. Please wait until 2.6.23.-rt is stable. Thereafter, let's create together a kvm version that works in an rt-kernel and let's make sure that from this moment onwards subsequent kvm upgrade changes are tested in an rt-kernel before being released. --cbe ------------------------------------------------------------------------- This SF.net email is sponsored by: Splunk Inc. Still grepping through log files to find problems? Stop. Now Search log events and configuration files using AJAX and a browser. Download your FREE copy of Splunk now >> http://get.splunk.com/