(In reply to comment #=
62)
> I do have 2 gig, but looking at the screenshot o=
f elemantal to be attached I
> see that used and requested differ.

That's probably because of VRAM fragmentation. (BTW, I find it easier to ke=
ep
track of this with requested-VRAM+VRAM-usage,requested-GTT+GTT-usage instea=
d of
requested-VRAM+requested-GTT,VRAM-usage+GTT-usage)

> This shot doesn't really show how long the pause=
s are - they are really bad,
> it takes about 2 minutes to render the first few frames with pauses of=
 many
> seconds after that.
>=20
> It's so bad it's hard to tell whether the revert helps - probably not,=
 I
> guess it's something different. Have you tried Elemental?

Yes, but even on Kaveri with only 1G of VRAM, it doesn't take two minutes f=
or
it to get going, and I don't notice such long pauses either.

So I think it's better if we track the UE4 issues in a separate report, and=
 it
would be great if you guys could bisect the kernel or Mesa for that.

(In reply to comment #65)
> Keep in mind that revert broke 32bit complitely,=
 lot of corruption :)

I haven't been able to reproduce that. If you still can, please file a bug =
for
it, as there's nothing preventing the kernel from using GTT instead of VRAM
when the latter is full.

> I am not trying other demos , but seems like new=
er kernels requests more
> VRAM from the apps :)

The Mesa commit in question makes the r600g and radeonsi drivers try to use
VRAM for more things, but only with newer kernels, because older kernels di=
dn't
guarantee reliability when using VRAM for those things.