On Thu, Jan 7, 2021 at 10:10 AM Daniel Pocock <daniel(a)pocock.pro> wrote:
On 07/01/2021 12:35, Dan Horák wrote:
> Hi Daniel,
> On Wed, 6 Jan 2021 14:11:37 +0100
> Daniel Pocock <daniel(a)pocock.pro> wrote:
>> We did some more troubleshooting of AMD Radeon issues on ppc64
>> As with Nouveau, it looks like a change from 64k to 4k page size got it
>> working again with RX 5700. I suspect it will be similar for RX 6800 if
>> we can get some of them, they are a good complement for the compute power.
>> The issue is page size, not ppc64
> are you talking about Maurizio's issue? When I was talking with the guy
> who fixed the Navi 10 driver for Power, he wasn't aware of any page
> size issues. But it sounds plausible.
Yes, it is in the Raptor forum
To save reading, I gave him the following in an apt repository:
- 5.9.6 kernel with 4k page size
- mesa 20.3
- deps for mesa (llvm-11, libdrm, ...)
He took the 2020-10-22 firmware snapshot from Debian unstable
He disabled Wayland, to use Xorg
I'm hoping that exactly the same set of packages will work for me
whenever I can get my hands on an RX 6800 XT card.
As mentioned elsewhere in this thread and in various parts of the Raptor
forum, especially this thread, there are a range of applications
where page size appears to have some impact.
I'd like to emphasize that there are a range of issues where page size
does not appear to be a factor, there are a backlog of these issues.
Therefore, emphasizing this quite strongly, I feel it is better for
people to run 4k page size on workstations from F-34 so we can clearly
flush out the PPC issues on 4k before we even begin to address issues
with 64k. As examples, I have issues with Blender, Firefox and
JPEGs in OBS where page size has been eliminated but I also have
another issue with Firefox, or maybe v4l2-loopback, where page size
is a factor.
Vikings and Raptor hope to sell a lot more of these systems when they go
live in 2021. Vikings in particular has put great effort into a
German-engineering water cooling solution, there is a leaked photo in
the Raptor forum. Personally, I already identified the traps in this
platform within hours of unboxing but I know a lot of the users,
including Fedora users, will benefit from a slightly softer landing on
POWER9. I can't personally spend time following every issue through to
completion myself (unless somebody wants to offer me a bounty) but I try
to document them as well as I can both here and in the bug trackers.
You could make a Change proposal to switch Fedora on POWER back to 4k
page sizes. Or just talk to the Fedora kernel maintainers about
switching it back. We did this four years ago for ARM (as Peter
noted), and if it really continues to be a problem for desktop
POWER systems, then switching back makes sense.
真実はいつも一つ！/ Always, there's only one truth!