On Tue, Jan 12, 2016 at 03:07:03PM +0100, Daniel Vetter wrote: > On Tue, Jan 12, 2016 at 11:19:26AM +0000, John Harrison wrote: > > On 11/01/2016 22:16, Chris Wilson wrote: > > >On Mon, Jan 11, 2016 at 06:42:39PM +0000, John.C.Harrison@xxxxxxxxx wrote: > > >>From: John Harrison <John.C.Harrison@xxxxxxxxx> > > >> > > >>MMIO flips are the preferred mechanism now but more importantly, > > >Says who? > > > > I asked this exact question at the linux architecture forum quite some time > > ago - does the scheduler need to worry about managing non-batch buffer work > > such as page flips. The answer from everyone present was no, MMIO flips are > > the way to go so don't over complicate the scheduler trying to support ring > > flips. Indeed, execlist mode already forces MMIO flips anyway. Two wrongs do not make a right, as they say. CS flips work very nicely with execlists. > Atomic will kill CS flips. We can mourn them and scream about the loss, > but imo best is to just skip that all and move on to acceptance. So mmio > flips (or well, atomic flips) is still the way to go for everything. The real issue I think here is that not trying to feed a request into the scheduler for the flip has lead to a poor interface into the scheduler. For a CS flip request, we know the ordering, it's contents, we have to choose the context though, but we have a good idea of the deadline which gives a good challenge to a scheduler. That was my take. -Chris -- Chris Wilson, Intel Open Source Technology Centre _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/intel-gfx
