On Wed, Jan 2, 2013 at 2:06 PM, Alexander Motin <m...@freebsd.org> wrote: > On 02.01.2013 18:08, Adrian Chadd wrote: >> >> .. I'm pretty damned sure we're going to need to enforce a "never >> earlier than X" latency. > > > Do you mean here that we should never wake up before specified time (just as > specified by the most of existing APIs), or that we should not allow sleep > shorter then some value to avoid DoS? At least on x86 nanosleep(0) doesn't > allow to block the system. Also there is already present mechanism for > specifying minimum timer programming interval in eventtimers(9) KPI.
I can see serious performance issues with some hardware (wireless comes to mind) if things happen too quickly. Intuition is that it could also play hob with VMs. I believe that the proper way is to wake between T_X and T_X + D. This assumes that D is max_wake_delay, not deviation, which leaves us at the original of (T_X) =< event_time =< (T_X + D). -- R. Kevin Oberman, Network Engineer E-mail: kob6...@gmail.com _______________________________________________ freebsd-current@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-current To unsubscribe, send any mail to "freebsd-current-unsubscr...@freebsd.org"
