On Tue, May 08, 2007 at 12:29:19PM +0900, Satoru Takeuchi wrote:
> > We used to be able to create kernel threads higher than any userspace
> > priority. If this is no longer true, I think that's OK: equal priority
> > still means we'll get scheduled, right?
>
> IF SCHED_RR, yes. However, if SCHED_FIFO, no. Such process doen't have timeslice
> and only relinquish CPU time voluntarily.
yeah ..this is truly a problem if SCHED_FIFO user-space cpu hog task is
running at MAX_USER_RT_PRIO (which happens to be same as max real-time
priority kernel threads can attain - MAX_RT_PRIO).
One option is to make MAX_USER_RT_PRIO < MAX_RT_PRIO. I am not sure what
semantics that will break (perhaps the real-time folks can clarify
that).
The other easier option is to add a wake_up_process_to_front() API in
sched.c, which essentially wakes up the process and enqueues the task to
the front of runqueue.
> # Hence this problem is complicated ;-(
--
Regards,
vatsa
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
[Index of Archives]
[Kernel Newbies]
[Netfilter]
[Bugtraq]
[Photo]
[Stuff]
[Gimp]
[Yosemite News]
[MIPS Linux]
[ARM Linux]
[Linux Security]
[Linux RAID]
[Video 4 Linux]
[Linux for the blind]
[Linux Resources]
