On Tue, 2006-12-19 at 17:32 -0800, john stultz wrote:
> On Wed, 2006-12-13 at 21:40 +0100, Roman Zippel wrote:
> > On Wed, 13 Dec 2006, john stultz wrote:
> > > > You don't have to introduce anything new, it's tick_length that changes
> > > > and HZ that becomes a variable in this function.
> > >
> > > So, forgive me for rehashing this, but it seems we're cross talking
> > > again. The context here is the dynticks code. Where HZ doesn't change,
> > > but we get interrupts at much reduced rates.
> >
> > I know and all you have to change in the ntp and some related code is to
> > replace HZ there with a variable, thus make it changable, so you can
> > increase the update interval (i.e. it becomes 1s/hz instead of 1s/HZ).
>
> Untested patch below. Does this vibe better with you are suggesting?
And here would be the follow on patch (again *untested*) for
CONFIG_NO_HZ slowing the time accumulation down to once per second.
thanks
-john
diff --git a/include/linux/timex.h b/include/linux/timex.h
index 8241e6e..3beb539 100644
--- a/include/linux/timex.h
+++ b/include/linux/timex.h
@@ -286,7 +286,11 @@ #endif /* !CONFIG_TIME_INTERPOLATION */
#define TICK_LENGTH_SHIFT 32
+#ifdef CONFIG_NO_HZ
+#define NTP_INTERVAL_FREQ (1)
+#else
#define NTP_INTERVAL_FREQ (HZ)
+#endif
#define NTP_INTERVAL_LENGTH (NSEC_PER_SEC/NTP_INTERVAL_FREQ)
/* Returns how long ticks are at present, in ns / 2^(SHIFT_SCALE-10). */
diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c
index d0ba190..53979a9 100644
--- a/kernel/hrtimer.c
+++ b/kernel/hrtimer.c
@@ -127,12 +127,14 @@ EXPORT_SYMBOL_GPL(ktime_get_ts);
*/
static void hrtimer_get_softirq_time(struct hrtimer_base *base)
{
+ struct timespec ts;
ktime_t xtim, tomono;
unsigned long seq;
do {
seq = read_seqbegin(&xtime_lock);
- xtim = timespec_to_ktime(xtime);
+ getnstimeofday(&ts);
+ xtim = timespec_to_ktime(ts);
tomono = timespec_to_ktime(wall_to_monotonic);
} while (read_seqretry(&xtime_lock, seq));
-
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