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    SubjectRe: [PATCH 1/8] posix clocks: introduce a syscall for clock tuning.
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    On Thu, 2010-09-23 at 19:31 +0200, Richard Cochran wrote:
    > A new syscall is introduced that allows tuning of a POSIX clock. The
    > syscall is implemented for four architectures: arm, blackfin, powerpc,
    > and x86.
    >
    > The new syscall, clock_adjtime, takes two parameters, the clock ID,
    > and a pointer to a struct timex. The semantics of the timex struct
    > have been expanded by one additional mode flag, which allows an
    > absolute offset correction. When specificied, the clock offset is
    > immediately corrected by adding the given time value to the current
    > time value.


    So I'd still split this patch up a little bit more.

    1) Patch that implements the ADJ_SETOFFSET (*and its implementation*)
    in do_adjtimex.

    2) Patch that adds the new syscall and clock_id multiplexing.

    3) Patches that wire it up to the rest of the architectures (there's
    still a bunch missing here).



    And one little nit in the code:

    > diff --git a/kernel/posix-timers.c b/kernel/posix-timers.c
    > index 9ca4973..446b566 100644
    > --- a/kernel/posix-timers.c
    > +++ b/kernel/posix-timers.c
    > @@ -197,6 +197,14 @@ static int common_timer_create(struct k_itimer *new_timer)
    > return 0;
    > }
    >
    > +static inline int common_clock_adj(const clockid_t which_clock, struct timex *t)
    > +{
    > + if (CLOCK_REALTIME == which_clock)
    > + return do_adjtimex(t);
    > + else
    > + return -EOPNOTSUPP;
    > +}


    Would it make sense to point to the do_adjtimex() in the k_clock
    definition for CLOCK_REALTIME rather then conditionalizing it here?



    thanks
    -john



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