[Cbe-oss-dev] [PATCH 3/3] spu sched: forced preemption at execution

[Christoph Hellwig]

On Sat, Feb 24, 2007 at 11:29:49AM -0300, Luke Browning wrote:
> > Currently these fields are never updated after the context creation,
> > so the lock is not needed.  But once we're doing dynamic timeslicing
> > we will need to introduce locking here.
> >
> 
> Hmm, the application should be able to change the priority and policy of a
> ctx, if it
> changes the priority of the controlling entity (ie. kernel thread or
> process).  The
> scheduling parameters should be able to be changed dynamically.

In Linux all scheduling information (priority, policy) is per-thread.
That means the syscall to set it can't run concurrently to us beeing
in this forced preemption code which is always run from the controlling
thread in spu_run.  That beeing said we should update the scheduling
information at ævery spu_run, which is a small change I've written
up and that will be sent out soon.