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SubjectRe: [patch 11/14] timekeeper read clock helper functions
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On Thu, 2009-08-13 at 17:40 +0200, Martin Schwidefsky wrote:
> plain text document attachment (timekeeper-helper.diff)
> From: Martin Schwidefsky <schwidefsky@de.ibm.com>
>
> Add timekeeper_read_clock_ntp and timekeeper_read_clock_raw and use
> them for getnstimeofday, ktime_get, ktime_get_ts and getrawmonotonic.
>
> Cc: Ingo Molnar <mingo@elte.hu>
> Cc: Thomas Gleixner <tglx@linutronix.de>
> Cc: john stultz <johnstul@us.ibm.com>
> Cc: Daniel Walker <dwalker@fifo99.com>
> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
> ---
> kernel/time/timekeeping.c | 91 +++++++++++++++++++---------------------------
> 1 file changed, 38 insertions(+), 53 deletions(-)
>
> Index: linux-2.6/kernel/time/timekeeping.c
> ===================================================================
> --- linux-2.6.orig/kernel/time/timekeeping.c
> +++ linux-2.6/kernel/time/timekeeping.c
> @@ -95,6 +95,40 @@ static void timekeeper_setup_internals(s
> timekeeper.mult = clock->mult;
> }
>
> +/* Timekeeper helper functions. */
> +static inline s64 timekeeping_get_ns(void)
> +{
> + cycle_t cycle_now, cycle_delta;
> + struct clocksource *clock;
> +
> + /* read clocksource: */
> + clock = timekeeper.clock;
> + cycle_now = clock->read(clock);
> +
> + /* calculate the delta since the last update_wall_time: */
> + cycle_delta = (cycle_now - clock->cycle_last) & clock->mask;
> +
> + /* return delta convert to nanoseconds using ntp adjusted mult. */
> + return clocksource_cyc2ns(cycle_delta, timekeeper.mult,
> + timekeeper.shift);
> +}

Again, not a huge issue, but if we kept the read() out of this function
and instead passed the cycle_now value in as a argument, we could also
use this function in timekeeping_forward_now()


thanks
-john




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