From: Stephen Hemminger <stephen@networkplumber.org>
To: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: "Alex Ng \(LIS\)" <alexng@microsoft.com>,
Haiyang Zhang <haiyangz@microsoft.com>,
"linux-kernel\@vger.kernel.org" <linux-kernel@vger.kernel.org>,
John Stultz <john.stultz@linaro.org>,
"devel\@linuxdriverproject.org" <devel@linuxdriverproject.org>,
Thomas Gleixner <tglx@linutronix.de>
Subject: Re: [PATCH 3/4] hv_util: use do_adjtimex() to update system time
Date: Mon, 9 Jan 2017 09:58:27 -0800 [thread overview]
Message-ID: <20170109095827.0cc364ad@xeon-e3> (raw)
In-Reply-To: <87lguk6sjk.fsf@vitty.brq.redhat.com>
On Mon, 09 Jan 2017 18:40:15 +0100
Vitaly Kuznetsov <vkuznets@redhat.com> wrote:
> Stephen Hemminger <stephen@networkplumber.org> 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.
next prev parent reply other threads:[~2017-01-09 17:58 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-01-02 19:41 [PATCH 0/4] hv_util: adjust system time smoothly Vitaly Kuznetsov
2017-01-02 19:41 ` [PATCH 1/4] timekeeping: export do_adjtimex() to modules Vitaly Kuznetsov
2017-01-02 19:41 ` [PATCH 2/4] hv_util: switch to using timespec64 Vitaly Kuznetsov
2017-01-02 19:41 ` [PATCH 3/4] hv_util: use do_adjtimex() to update system time Vitaly Kuznetsov
2017-01-02 23:24 ` Alex Ng (LIS)
2017-01-03 12:32 ` Vitaly Kuznetsov
2017-01-03 19:48 ` Alex Ng (LIS)
2017-01-09 17:19 ` Stephen Hemminger
2017-01-09 17:40 ` Vitaly Kuznetsov
2017-01-09 17:58 ` Stephen Hemminger [this message]
2017-01-09 18:14 ` Vitaly Kuznetsov
2017-01-09 18:31 ` Stephen Hemminger
2017-01-02 19:41 ` [PATCH 4/4] hv_util: improve time adjustment accuracy by disabling interrupts Vitaly Kuznetsov
2017-01-02 19:50 ` Stephen Hemminger
2017-01-03 12:28 ` Vitaly Kuznetsov
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