[RFCv3 0/5] enable migration of driver pages

[Kirill A. Shutemov]

On Thu, Jul 09, 2015 at 04:33:01PM +0300, Ville Syrjälä wrote:
> On Thu, Jul 09, 2015 at 03:08:48PM +0200, Daniel Vetter wrote:
> > On Thu, Jul 09, 2015 at 08:55:25AM +0900, Gioh Kim wrote:
> > > 
> > > 
> > > 2015-07-09 오전 7:47에 Dave Airlie 이(가) 쓴 글:
> > > >>>
> > > >>>
> > > >>>Can the various in-kernel GPU drivers benefit from this?  If so, wiring
> > > >>>up one or more of those would be helpful?
> > > >>
> > > >>
> > > >>I'm sure that other in-kernel GPU drivers can have benefit.
> > > >>It must be helpful.
> > > >>
> > > >>If I was familiar with other in-kernel GPU drivers code, I tried to patch
> > > >>them.
> > > >>It's too bad.
> > > >
> > > >I'll bring dri-devel into the loop here.
> > > >
> > > >ARM GPU developers please take a look at this stuff, Laurent, Rob,
> > > >Eric I suppose.
> > > 
> > > I sent a patch, https://lkml.org/lkml/2015/3/24/1182, and my opinion about compaction
> > > to ARM GPU developers via Korea ARM branch.
> > > I got a reply that they had no time to review it.
> > > 
> > > I hope they're interested to this patch.
> > 
> > i915 gpus would support 64kb and 2mb pages, but we never implemented this.
> > I don't think this would fit for gem based drivers since our backing
> > storage is shmemfs. So if we want to implement page migration (which we'd
> > probably want to make large pages work well) we'd need to pimp shmem to a)
> > hand large pages to us b) forward the migrate calls. Probably that means
> > we need to build our own gemfs reusing shmemfs code.
> 
> AFAIK there are efforts ongoing to make large pages work with shmem.
> 
> Kirill, IIRC you mentioned that you're were looking into this a while
> back?

I work in this direction, but don't have anything to show at the moment.

Hugh has published his implementation of huge tmpfs back in February:

http://lkml.kernel.org/g/alpine.LSU.2.11.1502201941340.14414@eggly.anvils

-- 
 Kirill A. Shutemov