From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dong Liu Subject: Re: RT patch and XEN Date: Wed, 27 Jun 2012 23:16:42 -0400 Message-ID: <4FEBCC9A.8070505@gmail.com> References: <4FEB729E.2080508@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: linux-rt-users@vger.kernel.org To: Sven-Thorsten Dietrich Return-path: Received: from mail-vc0-f174.google.com ([209.85.220.174]:40633 "EHLO mail-vc0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754206Ab2F1DQs (ORCPT ); Wed, 27 Jun 2012 23:16:48 -0400 Received: by vcbf11 with SMTP id f11so1219210vcb.19 for ; Wed, 27 Jun 2012 20:16:47 -0700 (PDT) In-Reply-To: Sender: linux-rt-users-owner@vger.kernel.org List-ID: On 6/27/12 7:04 PM, Sven-Thorsten Dietrich wrote: > > On Jun 27, 2012, at 1:52 PM, Dong Liu wrote: > >> Hi, >> >> I tried to run PREEMPT_RT patch under XEN, but running into some problem. >> >> My kernel is 3.4.3 with -r11 patch. XEN is 4.1.2. The kernel is running file as dom0. But as a Paravirtual (PV) domU, the system crashes normal when there is network traffic. kernel message indicates is kernel/rtmutex_common.h:75, which is, >> >> BUG_ON(w->lock != lock); >> >> Is this a known problem? > > I would consider this hopeless. > > Xen will not get you RT performance nor full preemption, so there is no point in running RT on Xen. > > Use KVM > > Sven > I also thought of that, because the RT performance or full preemption also depends on Xen's code, scheduler and spin lock etc. But I just want to have a system for benchmark comparison. Running the RT kernel as HVM guest is fine. Thanks! Dong