From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: [PATCH] Lazy FPU save/restore Date: Mon, 19 Feb 2007 10:13:26 +0200 Message-ID: <45D95C26.9050309@qumranet.com> References: <45D502A1.5000303@codemonkey.ws> <45D81EB6.9010407@qumranet.com> <45D861CD.4020207@qumranet.com> <45D87B22.6070403@codemonkey.ws> <45D87C2E.2090806@qumranet.com> <45D89917.9090003@qumranet.com> <45D8D96B.50104@codemonkey.ws> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: kvm-devel To: Anthony Liguori Return-path: In-Reply-To: <45D8D96B.50104-rdkfGonbjUSkNkDKm+mE6A@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 Anthony Liguori wrote: > Avi Kivity wrote: >> Avi Kivity wrote: >>>> >>>> I'll have to try and setup a 64 bit system. I cannot reproduce on >>>> my 32bit system with your test program. >>> >>> It may be related to 64-bit (as that uses sse for floating point), >>> or to the fact that I use ssh on a remote host, which causes more >>> context switches. I'll try to reproduce on 32 bits with my setup. >>> >> >> It doesn't reproduce on a 32-bit host. However, it does reproduce on >> a 32-bit guest on a 64-bit host, and on a 32-bit user load running in >> a 64-bit guest on a 64-bit host. > > Thanks, I'll setup a 64 bit partition and start debugging. I'm a bit > confused though, I thought CR0.TS even covers SIMD instructions? It does, and the fact that a 32-bit guest suffers from the same issue indicate that sse is not the cause. Locking the vcpu to a cpu does not change the failures, so it isn't related to vcpu migration. -- Do not meddle in the internals of kernels, for they are subtle and quick to panic. ------------------------------------------------------------------------- Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT & business topics through brief surveys-and earn cash http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV