Why there is no GPU swap support in linux based systems?

[Greg KH]

On Tue, Feb 09, 2016 at 09:12:23PM +0300, alexhoppus wrote:
> (The things below are mainly related to arm mali systems)
> 
> Hi. Actually i want to know - why there is no GPU Swap support in Linux 
> based systems? It seems that the GPU works with graphical contexts in 
> the same fashion as CPU handle things. I mean there are page faults, GPU 
> have its own MMU, the memory used by GPU devices allocated via trivial 
> page_alloc mechanism. You would say that performance is a reason, but 
> there are some swap backends like zram: they use in-memory compression 
> instead of disk swapping. Moreover, i think there would be a GPU data 
> which could be swapped without significant drawbacks, because it 
> accessed very rare.

That's not how GPU devices work.  But if you think you could help
implement this, I'm sure the graphic developers are always welcome to
working patches being sent to them for review.

best of luck,

greg k-h