I think that most of the hangup was a lack of agreement on how the API should work wrt leap seconds.
I've always thought that the Right Way to represent a UTC time is nanoseconds since some epoch, where every potential leap second counts. Pros: - Unambiguously convertible to and from year/month/day/hour/minute/second/nanosecond. - Monotonic - Compact Cons: - Computing differences between timestamps requires a table. (Note: y/m/d/h/m/s/ns has the same problem.) - Weird: no one does this - If you naively subtract times, you end up with jumps forward. (But jumps forward are much less likely to break things than jumps backwards.) - Almost, but not quite, compatible with timespec, so it could cause confusion. If someone wants a hard problem, find a way to implement clock_gettime that almost never spins or otherwise block and is continuous. I've thought about it a bit and have something that almost works. --Andy On Wed, Sep 4, 2013 at 2:18 AM, Arun Sharma <asha...@fb.com> wrote: > A couple of years ago Andy posted this patch series: > > http://thread.gmane.org/gmane.linux.kernel/1233209/ > > These patches have been in use at facebook for a couple of years and along > with a vDSO implementation of thread_cpu_time(), they have proven useful for > our profilers. > > I didn't see any arguments against this patch series. Did I miss some > discussion on the topic? > > -Arun -- Andy Lutomirski AMA Capital Management, LLC -- 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/
