On Thu, 4 Oct 2007, Daniel Eischen wrote: > On Thu, 4 Oct 2007, Jeff Roberson wrote: > >> On Thu, 4 Oct 2007, Daniel Eischen wrote: >> >>> On Thu, 4 Oct 2007, Jeff Roberson wrote: >>> >>>> >>>> I believe I have fixed this bug in the enclosed patch. It is rooted from >>>> /usr/src/sys so you should cd there to apply it. >>> >>> This doesn't break realtime threads doing a sched_yield() does >>> it? I couldn't easily see how the priority gets set back into >>> the realtime class range. But then, maybe I'm a dummy ;-) >> >> Well the historical behavior was for sched_yield() to not adjust >> priorities. It just requeues at the back of the queue for that priority. Xu >> changed this in 7.0 but he didn't answer my mail as to why. We have a >> yield() call that does drop to the max timeshare priority, however, it >> doesn't seem to have a man page. >> >> The code removed was this: >> >> - if (td->td_pri_class == PRI_TIMESHARE) >> - sched_prio(td, PRI_MAX_TIMESHARE); >> >> >> So it really only effected timesharing threads. > > As I read the change, now it affects real-time (which is the > desired behavior since it is a POSIX real-time extension). > But it should have POSIX-defined behavior, which is to requeue > at the back of the queue for that priority. It effected real-time before. There is a mi_switch() after that priority adjustment. That switch re-adds the thread at the back of the queue for that priority. This patch just removes the priority adjustment for timeshare threads. > > -- > DE > _______________________________________________ > freebsd-current_at_freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-current > To unsubscribe, send any mail to "freebsd-current-unsubscribe_at_freebsd.org" >Received on Fri Oct 05 2007 - 00:08:20 UTC
This archive was generated by hypermail 2.4.0 : Wed May 19 2021 - 11:39:18 UTC