on 17/12/2011 23:20 Adrian Chadd said the following: > Erm, just as a random question - since device drivers (and GEOM) run > as separate threads, has anyone looked into what kind of effects the > scheduler has on these? > > I definitely have measurable throughput/responsiveness differences > between ULE and 4BSD (and preempt/non-preempt on 4BSD) on my MIPS > boards when they're bridging traffic. I wonder if there's something > strange going on with the scheduling and preemption of driver netisrs, > taskqueues, the fast interrupt handlers, etc. > > This may -not- be a userland specific problem..
That's an interesting idea. From the recent discussion about USB I can conclude that USB threads run at higher priority than GEOM threads: PI_NET/PI_DISK vs PRIBIO. The former is from the ithread range, the latter is from the regular kernel range. Maybe it would make sense to give the GEOM threads a priority from the ithread range too - given their role and importance. -- Andriy Gapon _______________________________________________ freebsd-stable@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-stable To unsubscribe, send any mail to "freebsd-stable-unsubscr...@freebsd.org"
