On Thu, 2010-08-19 at 22:07 -1000, Zachary Amsden wrote: > Add a kernel call to get the number of nanoseconds since boot. This > is generally useful enough to make it a generic call. Few comments here. > Signed-off-by: Zachary Amsden <zamsden@xxxxxxxxxx> > --- > include/linux/time.h | 1 + > kernel/time/timekeeping.c | 27 +++++++++++++++++++++++++++ > 2 files changed, 28 insertions(+), 0 deletions(-) > > diff --git a/include/linux/time.h b/include/linux/time.h > index ea3559f..5d04108 100644 > --- a/include/linux/time.h > +++ b/include/linux/time.h > @@ -145,6 +145,7 @@ extern void getnstimeofday(struct timespec *tv); > extern void getrawmonotonic(struct timespec *ts); > extern void getboottime(struct timespec *ts); > extern void monotonic_to_bootbased(struct timespec *ts); > +extern s64 getnsboottime(void); So instead of converting the timespec from getboottime, why did you add a new interface? Also if not a timespec, why did you pick a s64 instead of a ktime_t? > extern struct timespec timespec_trunc(struct timespec t, unsigned gran); > extern int timekeeping_valid_for_hres(void); > diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c > index caf8d4d..d250f0a 100644 > --- a/kernel/time/timekeeping.c > +++ b/kernel/time/timekeeping.c > @@ -285,6 +285,33 @@ void ktime_get_ts(struct timespec *ts) > } > EXPORT_SYMBOL_GPL(ktime_get_ts); > > + > +/** > + * getnsboottime - get the bootbased clock in nsec format > + * > + * The function calculates the bootbased clock from the realtime > + * clock and the wall_to_monotonic offset and stores the result > + * in normalized timespec format in the variable pointed to by @ts. > + */ > +s64 getnsboottime(void) > +{ > + unsigned int seq; > + s64 secs, nsecs; > + > + WARN_ON(timekeeping_suspended); > + > + do { > + seq = read_seqbegin(&xtime_lock); > + secs = xtime.tv_sec + wall_to_monotonic.tv_sec; > + secs += total_sleep_time.tv_sec; > + nsecs = xtime.tv_nsec + wall_to_monotonic.tv_nsec; > + nsecs += total_sleep_time.tv_nsec + timekeeping_get_ns(); > + > + } while (read_seqretry(&xtime_lock, seq)); > + return nsecs + (secs * NSEC_PER_SEC); > +} > +EXPORT_SYMBOL_GPL(getnsboottime); You forgot to include the boottime.tv_sec/nsec offset in this. Take a look again at getboottime() thanks -john -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html