Unplayable framerates in game but specific kernel versions work, maybe amdgpu problem

[Alex Deucher]

On Fri, Jun 13, 2025 at 3:38 PM <machion at disroot.org> wrote:
>
> Hi,
> sorry for the delay.
> Besides less time, I had to make myself familiar with bisecting and
> again kernel compiling. Last time I compiled the kernel myself was
> around 2010 I think.
>
> Anyway it seems I found the bad commit. The result after bisecting 10
> commits is:
>
> a53d959fe660341788cb8dbc3ac3330d90a09ecf is the first bad commit
> commit a53d959fe660341788cb8dbc3ac3330d90a09ecf
> Author: Christian König <christian.koenig at amd.com>
> Date:   Thu Mar 20 14:46:18 2025 +0100
>
>      drm/amdgpu: immediately use GTT for new allocations
>
>      commit a755906fb2b8370c43e91ba437ae1b3e228e8b02 upstream.
>
>      Only use GTT as a fallback if we already have a backing store. This
>      prevents evictions when an application constantly allocates and
> frees new
>      memory.
>
>      Partially fixes
>      https://gitlab.freedesktop.org/drm/amd/-/issues/3844#note_2833985.
>
>      Signed-off-by: Christian König <christian.koenig at amd.com>
>      Fixes: 216c1282dde3 ("drm/amdgpu: use GTT only as fallback for
> VRAM|GTT")
>      Acked-by: Alex Deucher <alexander.deucher at amd.com>
>      Signed-off-by: Alex Deucher <alexander.deucher at amd.com>
>      Cc: stable at vger.kernel.org
>      Signed-off-by: Greg Kroah-Hartman <gregkh at linuxfoundation.org>
>
>   drivers/gpu/drm/amd/amdgpu/amdgpu_object.c | 4 ++--
>   1 file changed, 2 insertions(+), 2 deletions(-)

Unfortunately reverting that commit will reintroduce a similar
performance issue for lots of other uses.  See:
https://gitlab.freedesktop.org/drm/amd/-/issues/3844#note_2827990
for a description of the fundemental problem.

Alex

>
> Marion
>
>
> Am 2025-05-08 15:18, schrieb Alex Deucher:
> > On Thu, May 8, 2025 at 9:13 AM <machion at disroot.org> wrote:
> >>
> >> Hello kernel/driver developers,
> >>
> >> I hope, with my information it's possible to find a bug/problem in the
> >> kernel. Otherwise I am sorry, that I disturbed you.
> >> I only use LTS kernels, but I can narrow it down to a hand full of
> >> them,
> >> where it works.
> >>
> >> The PC: Manjaro Stable/Cinnamon/X11/AMD Ryzen 5 2600/Radeon HD
> >> 7790/8GB
> >> RAM
> >> I already asked the Manjaro community, but with no luck.
> >>
> >> The game: Hellpoint (GOG Linux latest version, Unity3D-Engine v2021),
> >> uses vulkan
> >>
> >> ---
> >>
> >> I came a long road of kernels. I had many versions of 5.4, 5.10, 5.15,
> >> 6.1 and 6.6 and and the game was always unplayable, because the frames
> >> where around 1fps (performance of PC is not the problem).
> >> I asked the mesa and cinnamon team for help in the past, but also with
> >> no luck.
> >> It never worked, till on 2025-03-29 when I installed 6.12.19 for the
> >> first time and it worked!
> >>
> >> But it only worked with 6.12.19, 6.12.20 and 6.12.21
> >> When I updated to 6.12.25, it was back to unplayable.
> >
> > Can you bisect to see what fixed it in 6.12.19 or what broke it in
> > 6.12.25?  For example if it was working in 6.12.21 and not working in
> > 6.12.25, you can bisect between 6.12.21 and .25.
> >
> > Alex
> >
> >>
> >> For testing I installed 6.14.4 with the same result. It doesn't work.
> >>
> >> I also compared file /proc/config.gz of both kernels (6.12.21 <>
> >> 6.14.4), but can't seem to see drastic changes to the graphical part.
> >>
> >> I presume it has something to do with amdgpu.
> >>
> >> If you need more information, I would be happy to help.
> >>
> >> Kind regards,
> >> Marion