Re: [PATCH 3/4] hv_util: use do_adjtimex() to update system time

From: Stephen Hemminger
Date: Mon Jan 09 2017 - 12:58:40 EST


On Mon, 09 Jan 2017 18:40:15 +0100
Vitaly Kuznetsov <vkuznets@xxxxxxxxxx> wrote:

> Stephen Hemminger <stephen@xxxxxxxxxxxxxxxxxx> writes:
>
> > An alternative would be for hyper-v util to provide a clocksource device and
> > let NTP manage the adjustment. The advantage of this would be HV util not fighting
> > with NTP, and using standard API's. The downside would be the complexity of configuring
> > NTP, and difficulty of writing a clock source pseudo device.
>
> Yes, I see this option. But as I wrote to John I'm afraid we'll have to
> come up with a custom interface from hv_util to userspace which no NTP
> server will want to support (because, first of all, it's not about
> 'network time' any more). We can write our own daemon which will read
> from this interface and do adjtimex but in this case I don't see much
> value in this data traveling from kernel to userspace and back...
>

Master NTP servers are connected to authoritative clock sources. I have no idea how
that is configured, but it should be possible.