Re: amdgpu hard freeze with Firefox MOZ_ACCELERATED/MOZ_WEBRENDER

> I've had intermittent hard crashes on my amdgpu machine too, starting at =
some
> point between 7.8 and 7.9 (and, at first, I ascribed it to another cause,=
 so I didn't
> really note when it started happening). I now _think_ it's caused by prog=
rams --
> including, but not only Firefox -- that use hardware acceleration
> (in my case e.g. Alacritty). Unfortunately I have absolutely no idea why =
and given
> how big amdgpu and friends are, debugging this must be a nightmare.

Since filing the bug report I found that the work-around of disabling hardw=
are
acceleration in Firefox was insufficient. Running llama.cpp with Vulkan
acceleration also sometimes triggered the freeze. This indicates that it mi=
ght
be the GPU driver generally rather than just an interaction with Firefox.
Your experience with Alacritty seems consistent with that assumption.

> If you have the ability to do so, you could bisect snapshots (e.g. using
> [1]) and see when the problem was introduced. If that narrows it down,
> it might make a big difference to fixing things.

I upgraded from 7.9 to a current snapshot:

$ sysctl kern.version
kern.version=3DOpenBSD 7.9-current (GENERIC.MP) #2: Fri Jun 12 12:08:26 MDT=
 2026
    [email protected]:/usr/src/sys/arch/amd64/compile/GENERIC.MP

After moving to current, I reenabled Firefox acceleration and ran benchmark=
ing of
llama.cpp with Vulkan. I have not managed to reproduce the freeze with this=
 snapshot
and I was able to reproduce it somewhat reliably with 7.9. I feel that I ne=
ed to
use the system a bit more intensely before I can be confident the issue is =
gone, but
this indicates the issue has already been resolved with some change between=
 7.9
and the June 12, 2026, snapshot.