[RFC/RFT] calloutng
Alexander Motin
mav at FreeBSD.org
Thu Jan 3 16:12:26 UTC 2013
On 03.01.2013 16:45, Bruce Evans wrote:
> On Wed, 2 Jan 2013, Alexander Motin wrote:
>> More important for scheduling fairness thread's CPU percentage is also
>> based on hardclock() and hiding from it was trivial before, since all
>> sleep primitives were strictly aligned to hardclock(). Now it is
>> slightly less trivial, since this alignment was removed and user-level
>> APIs provide no easy way to enforce it.
>
> %cpu is actually based on statclock(), and not even used for scheduling.
May be for SCHED_4BSD, but not for SCHED_ULE. In SCHED_ULE both %cpu
and thread priority based on the same ts_ticks counter, that is based on
hardclock() as time source. Interactivity calculation uses alike logic
and uses the same time source.
--
Alexander Motin
More information about the freebsd-arch
mailing list