kse: high prio threads starving low prio threads

Daniel Eischen deischen at freebsd.org
Tue Jan 31 17:28:45 PST 2006

On Tue, 31 Jan 2006, Kurt Miller wrote:

> I'm working on 1.5 jdk certification on 5.4 and 6.0. One of the
> jck tests hangs because a high priority thread that is yielding
> is starving the lower priority threads. The following program
> demonstrates this problem. Using libthr the program finishes.
> Using kse hangs using all three scheduling policies.
> Is this the expected behavior of kse?

It is the expected behavior for any POSIX threads library
that supports SCHED_FIFO and priorities and also running
on a system with one scheduling allocation domain (one CPU).
libthr does not support posix priority scheduling.

> Is there a work-around to the starving issue?

It is working as it should.  Recode it not to use priorities
if that is what you want.


More information about the freebsd-threads mailing list