Re: [PATCH V7 1/8] ntp: add ADJ_SETOFFSET mode bit

From: Alexander Gordeev
Date: Wed Dec 22 2010 - 04:58:37 EST


Ð Tue, 21 Dec 2010 13:59:44 -0800
john stultz <johnstul@xxxxxxxxxx> ÐÐÑÐÑ:

> On Wed, 2010-12-22 at 06:13 +0900, Kuwahara,T. wrote:
> > On Wed, Dec 22, 2010 at 4:37 AM, john stultz <johnstul@xxxxxxxxxx> wrote:
> > > adjtimex is a linux specific interface, which is compatible but not
> > > identical to the ntp specified interfaces. The ntp client code already
> > > has Linux specific modifications, so I don't think we have to worry
> > > about 0x40 specifically being reserved by the NTP client.
> >
> > But struct timex is not linux-specific...
>
> It is if you're compiling against linux's timex.h file.
>
> We already have a number of differences compared with BSD's timex mode
> definitions:
> We have ADJ_TICK: 0x4000, which is MOD_CLKB in FreeBSD.
> We also have ADJ_OFFSET_SINGLESHOT and ADJ_OFFSET_SS_READ which allow
> adjtimex act like the original ntp_adjtime.
>
> The key bit is that we map the shared MOD_* definitions that the NTP
> client uses to the linux specific ADJ_* values in the linux timex.h
>
> However, your concern does bring up a good point: 0x40 is MOD_PPSMAX in
> BSD, and we should at-least check to make sure that the PPS code that is
> currently floating around on the lists and is in akpm's tree hasn't
> already reserved that bit.
>
> Rodolfo, Alexander: Any comments here?

No, it is used neither in my patches nor in the original code. The only
change my patches do to timex.h is adding hardpps().

--
Alexander

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