> -----Original Message----- > From: Richard Cochran [mailto:richardcochran@xxxxxxxxx] > Sent: Tuesday, October 14, 2014 9:26 PM > To: Thomas Shao > Cc: tglx@xxxxxxxxxxxxx; gregkh@xxxxxxxxxxxxxxxxxxx; linux- > kernel@xxxxxxxxxxxxxxx; devel@xxxxxxxxxxxxxxxxxxxxxx; olaf@xxxxxxxxx; > apw@xxxxxxxxxxxxx; jasowang@xxxxxxxxxx; KY Srinivasan > Subject: Re: [PATCH 2/2] hyperv: Implement Time Synchronization using host > time sample > > On Tue, Oct 14, 2014 at 01:04:35PM +0000, Thomas Shao wrote: > > > I really don't see the need for this. We have NTP. If the guests > > > want to, they may use it. Otherwise, they have a free running clock, just > like real machines. > > > > > Sometimes the user can't setup NTP. For example the guest OS didn't > > have network connection. And in some cases, they may want the guest > time sync with host. > > With the existing hyper-v time source, the system clock will has > > around 1.5 second time drift per day. If the workload in the host is heavy, > the number could be larger. > > So this feature is really useful for some scenarios. > > Any real machine without networking (and without GPS etc) will drift. That is > just life, tough as it is. Why should we treat these guests any differently than > real machines? > > Furthermore, without networking you really don't have a compelling need > for correct absolute time in the first place. The host machine can be configure with NTP. And in this case, making guest time sync with host is useful. > > Thanks, > Richard _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
