From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dor Laor Subject: Re: Windows 2003: ping -n doesn't wait Date: Sat, 24 Jan 2009 01:53:46 +0200 Message-ID: <497A588A.40209@redhat.com> References: <20090123205512.GA3911@amt.cnet> Reply-To: dlaor@redhat.com Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: Sven Rudolph , kvm@vger.kernel.org, "Roedel, Joerg" To: Marcelo Tosatti Return-path: Received: from mx2.redhat.com ([66.187.237.31]:46013 "EHLO mx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753062AbZAWXxe (ORCPT ); Fri, 23 Jan 2009 18:53:34 -0500 In-Reply-To: <20090123205512.GA3911@amt.cnet> Sender: kvm-owner@vger.kernel.org List-ID: Marcelo Tosatti wrote: > On Tue, Jan 20, 2009 at 03:53:06PM +0100, Sven Rudolph wrote: > >> Hello, >> >> first the facts required by bug reporting guidelines: >> >> - two Quad-Core AMD Opteron(tm) Processors 2352 >> - kvm-83 (both kernel and userland) >> - Host kernel: 2.6.28.1, x86_64 >> - guest: >> - 4 CPUs assigned to this guest (-smp 4) >> - Microsoft Windows 2003 Server, Standard Edition, Service Pack 2 >> - qemu command line: >> qemu-system-x86_64 -m 4096 -boot c -hda hda.dat -smp 4 \ >> -net nic,macaddr=00:50:56:24:0b:37,model=virtio \ >> -net tap,ifname=vm03,script=no,downscript=no >> >> The problem: When running "ping -n 3 localhost" on the guest it should >> wait one second between each ping request and the time needed should >> be non-negative and below 10 ms. Instead, ping does not actually wait >> between sending the packets, and the time for the requests ist often >> displayed to be too large or negative. Simple examples: >> >> [WinNT] ping -n 3 localhost >> >> Ping wird ausgefhrt fr localhost [127.0.0.1] mit 32 Bytes Daten: >> >> Antwort von 127.0.0.1: Bytes=32 Zeit=-465ms TTL=128 >> Antwort von 127.0.0.1: Bytes=32 Zeit=-613ms TTL=128 >> Antwort von 127.0.0.1: Bytes=32 Zeit=-465ms TTL=128 >> > > Sven, Dor, > > Can you try to use the AMD CPU drivers for Windows? > > Take a look at http://forums.citrix.com/thread.jspa?threadID=93813 > > http://www.therightstuff.de/2007/06/05/The-Case-Of-The-Negative-Ping.aspx > > I don't doubt the KVM tsc syncing code for AMD is not involved, though. > > Installing AMD's driver for powerNow solves this issue. Joerg, can you please supply us some explanations? Thanks, Dor > -- > To unsubscribe from this list: send the line "unsubscribe kvm" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html >