Messages in this thread |  | | Date | Tue, 21 Oct 2014 10:23:40 +0200 (CEST) | From | Thomas Gleixner <> | Subject | RE: [PATCH v2 1/2] timekeeping: add EXPORT_SYMBOL_GPL for do_adjtimex() |
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On Tue, 21 Oct 2014, Thomas Shao wrote: > I didn't find a way to detect whether NTPd is running in the hyper-v module.
And you better do not try at all.
> In http://doc.ntp.org/4.1.0/ntpd.htm, it mentioned: Normally, the > time is slewed if the offset is less than the step threshold, which > is 128 ms by default, and stepped if above the threshold. > > In my implementation, I use 100ms as the threshold (maybe I should > change to 128?). If the time difference is less than 100ms, I just > do nothing. So, if NTPd is running, ideally it could keep the time > drift less than 128, so the adjustment in my patch will not get > triggered.
Your implementation has nothing to do with NTP at all. It's not even close to NTP. It's a random hack to inject host time or slew into timekeeping with the precision of a random number generator.
> And moreover, by default, the guest-host time sync is turn > off. There is a module parameter to control it. We'll also document > customer that do not turn on this if NTP is configured.
Pretty well thought out mechanism to ensure that people will get it wrong in the first place.
Thanks,
tglx
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