Using video memory on PS3 e.g. as SWAP?

Using video memory on PS3 e.g. as SWAP?

[René Rebe]

Hi all,

looking at the PS3 as one of the few PowerPC workstation options the RAM
is obviously quite limitted with just 256MB. I wonder if the 256MB of
video memory can be mapped or at least be used as super-fast SWAP?

Or are there news regarding accessing the video chip from Linux beside
the unaccelerated frame-buffer?

Regards,

=2D-=20
  Ren=E9 Rebe - ExactCODE GmbH - Europe, Germany, Berlin
  http://exactcode.de | http://t2-project.org | http://rene.rebe.name

Re: Using video memory on PS3 e.g. as SWAP?

[Benjamin Herrenschmidt]

On Sun, 2007-07-29 at 19:04 +0200, René Rebe wrote:
> Hi all,
> 
> looking at the PS3 as one of the few PowerPC workstation options the RAM
> is obviously quite limitted with just 256MB. I wonder if the 256MB of
> video memory can be mapped or at least be used as super-fast SWAP?
> 
> Or are there news regarding accessing the video chip from Linux beside
> the unaccelerated frame-buffer?

I can be mapped, and accessed directly with MMIO. Some folks did a
driver for that, not sure where about. It's fairly slow though. The
problem is that MMIO accesses to VRAM aren't fast. DMAs are supposed to
be but then, we don't have access to those.

Cheers,
Ben

Re: Using video memory on PS3 e.g. as SWAP?

[Marc Dietrich]

Am Sunday 29 July 2007 19:04 schrieb Ren=E9 Rebe:
> Hi all,
>
> looking at the PS3 as one of the few PowerPC workstation options the RAM
> is obviously quite limitted with just 256MB. I wonder if the 256MB of
> video memory can be mapped or at least be used as super-fast SWAP?

look here:
http://forums.ps2dev.org/viewtopic.php?t=3D8267

but the write speed is much slower than disk.

> Or are there news regarding accessing the video chip from Linux beside
> the unaccelerated frame-buffer?
>
> Regards,

=2D-=20
	"The enemy commits atrocities knowingly; if we make unfortunate mistakes, =
it=20
is involuntary."
		 Lord Arthur Ponsonby, "Falsehood in Wartime: Propaganda Lies of the Firs=
t=20
World War", 1928

Re: Using video memory on PS3 e.g. as SWAP?

[Geoff Levand]

=EF=BF=BD wrote:
> Hi all,
>=20
> looking at the PS3 as one of the few PowerPC workstation options the RA=
M
> is obviously quite limitted with just 256MB.=20


Can I recommend in the future you send this kind of PS3 specific inquiry =
to
the cbe-oss-dev mailing list?

  cbe-oss-dev@ozlabs.org
  https://ozlabs.org/mailman/listinfo/cbe-oss-dev


> I wonder if the 256MB of
> video memory can be mapped or at least be used as super-fast SWAP?


As Marc mentioned, some work was done using unsupported functionality of
the current hypervisor.  There is no assurance it will continue to work
with future system software updates.


> Or are there news regarding accessing the video chip from Linux beside
> the unaccelerated frame-buffer?


We plan to improve Linux graphics support, but we have not announced any
specifics.  The changes may make the above mentioned driver no longer wor=
k.

-Geoff