On 8/21/2014 3:47 PM, Chris Johns wrote: > On 21/08/2014 11:51 pm, Gedare Bloom wrote: >> On Thu, Aug 21, 2014 at 3:03 AM, Sebastian Huber >> <sebastian.hu...@embedded-brains.de> wrote: >>> On 20/08/14 16:05, Joel Sherrill wrote: >>> The clock handling is entirely broken on SMP and not scalable. Our clock >>> infrastructure is only good enough for uni-processor systems, but even here >>> the usage of nanosecond timestamps is suboptimal. I would rather use >>> something like the FreeBSD time hands: >>> >>> http://phk.freebsd.dk/pubs/timecounter.pdf >>> >> Nice. It looks like it would take: >> 1) Convert the 64-bit timestamps into bintime: a split time_t >> 'seconds' + uint64_t 'frac' format. The math is shown in the paper. >> 2) A lock-free ring buffer for the timehands. >> 3) The timecounter structure that describes the hw clock source, and a >> way to register timecounters from BSPs. >> 4) Rewrite tick handling to do the refresh operation. >> >> Did I miss anything? >> > If we implement this it would be nice to get NTP working cleanly with > RTEMS. The RSB is now building NTP. PHK has bounced some email with myself, Harlan Stenn, and Chris. He may be willing to help review. > Chris > _______________________________________________ > devel mailing list > devel@rtems.org > http://lists.rtems.org/mailman/listinfo/devel
-- Joel Sherrill, Ph.D. Director of Research & Development joel.sherr...@oarcorp.com On-Line Applications Research Ask me about RTEMS: a free RTOS Huntsville AL 35805 Support Available (256) 722-9985 _______________________________________________ devel mailing list devel@rtems.org http://lists.rtems.org/mailman/listinfo/devel
