Re: O(1) scheduler seems to lock up on sched_FIFO and sched_RR tasks
Joe Korty (email@example.com)
Wed, 18 Jun 2003 15:34:02 -0400
On Wed, Jun 18, 2003 at 09:47:24AM -0700, george anzinger wrote:
> It seems that once a SCHED_FIFO or SCHED_RR tasks gets control it does
> not yield to other tasks of higher priority.
> Attached is a test program (busyloop) that just loops doing
> gettimeofday() for the requested time and a little utility (rt) to run
> programs at real time priorities.
> Here is an annoted example of the problem:
> First, become root then:
> > rt 90 bash <-- run bash at priority 90 SCHED_RR
> > rt -f 30 busyloop 10 & <-- busyloop 10 at priority 30 SCHED_FIFO
> At this point the bash at priority 90 should be available, but is not.
> When the 10 second busyloop completes, bash returns.
When I boost the priority of each of the per-cpu 'events/%d' daemon to
96, the problem goes away.
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