> >That 0.1% kills me though. do you mean, that every 1 second, 1 >will be 1ms >off? And for every second thereafter, leaving me with 1 second >drift after >only 1000 seconds? >
Oh, that is not my intension :-( I just put a rought estimation here. In old Xen time, I know there are ~10-30 seconds shift after ~10 hours. >With the KVM 22 userspace and KVM 46 kernelspace I am 20 >seconds off, after >uptime of 33 minutes. That uptime is wrong by 20 seconds I >take, but it's >around 0.1% (relatively exactly even), so it's not what you >consider a bug? If you see same thing with KVM-46 user space, I think we should file a bug to track the issue. But I don't remeber how many changes happen since KVM-22 in user level. > >I am looking for an absolute value for time difference between >guest and host >that is supposed to be small over longer periods. Is that not >achievable for >a paravirtual guest?! I really need gettimeofday() calls to be >near exactly >the same value for applications in guest and host even after months. Except adding a hypercall to get host time (i.e. pv timer), or using network time, I think cetain amount of shift will be always there. > >To give a bit background: We are maintainers of an air traffic >management >system that receives UTC dated input from the outside, and >makes estimates >about flight positions based on that information. In order to >make correct >estimates about current position, the current time and the >observation time >must be compared, and errors in the current time easily will >lead to an error >in the range of miles. > thx,eddie ------------------------------------------------------------------------- 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/ _______________________________________________ kvm-devel mailing list kvm-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/kvm-devel
