[Linux-fbdev-devel] [PATCH 1/4 (updated)] ps3fb: thread updates

[Geert Uytterhoeven]

On Mon, 19 Feb 2007, Geert Uytterhoeven wrote:
> On Fri, 16 Feb 2007, Geert Uytterhoeven wrote:
> > On Fri, 16 Feb 2007, Christoph Hellwig wrote:
> > > > +	DEFINE_WAIT(wait);
> > > > +	DECLARE_WAIT_QUEUE_HEAD(wq);
> > > > +
> > > > +	while (!kthread_should_stop()) {
> > > > +		prepare_to_wait(&wq, &wait, TASK_INTERRUPTIBLE);
> > > > +		if (!ps3fb.is_kicked)
> > > > +			schedule();
> > > > +		finish_wait(&wq, &wait);
> > > > +		ps3fb.is_kicked = 0;
> > > > +		ps3fb_sync(0);	/* single buffer */
> > > 
> > > should probably be just:
> > > 
> > > 	while (!kthread_should_stop()) {
> > > 		ps3fb_sync(0);
> > > 		schedule();
> > > 	}
> > > 
> > > given that you don't need a waitqueue and a spurious wakeup here
> > > seems harmless.
> > 
> > Not always. If flipping is disabled, or external flip is enabled, you don't
> > want a spurious flip.
> 
> Looks like the waitqueue is needed. Without it ps3fbd runs at 100% CPU and +15
> million loops per second.

Nope, adding `set_current_state(TASK_INTERRUPTIBLE);' fixed it. Stay tuned for
a new patch.

Gr{oetje,eeting}s,

						Geert

--
Geert Uytterhoeven -- Sony Network and Software Technology Center Europe (NSCE)
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