On Wednesday 29 October 2014 10:21:18 Thomas Gleixner wrote:
> On Wed, 29 Oct 2014, Heena Sirwani wrote:
> > +time64_t ktime_get_seconds(void)
> > +{
> > + time64_t seconds;
> > + struct timekeeper *tk = &tk_core.timekeeper;
> > + unsigned int seq;
> > +
> > + WARN_ON(timekeeping_suspended);
>
> You want to have the same 64bit logic as you did for
> ktime_get_real_seconds. So on 64bit it boils down to return
> tk->ktime_sec.
>
> > +
> > + do {
> > + seq = read_seqcount_begin(&tk_core.seq);
> > + seconds = tk->ktime_sec;
> > +
> > + } while (read_seqcount_retry(&tk_core.seq, seq));
>
I wonder if we should just make tk->ktime_sec 'unsigned long' and
avoid the lock for 32-bit as well. Are there any theoretical
cases where the monotonic time could overflow a 32-bit integer?
As a minor optimization 's64 nsec_offset' could also be 'long',
since that only stores a number that is known to be less than
1000000000.
Arnd
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
