AMDGPU Driver Reverting The Buddy Allocator For Linux 5.19

[phoronix]

Phoronix: AMDGPU Driver Reverting The Buddy Allocator For Linux 5.19

The AMDGPU kernel graphics driver had been preparing to make use of the buddy allocator started by the Intel Linux graphics driver. But now with today's batch of DRM fixes that AMDGPU support is being reverted for Linux 5.19 due to it causing garbled screens for some users...

https://www.phoronix.com/scan.php?page=news_item&px=AMDGPU-Reverts-Buddy-Allocator

[aufkrawall]

Really worrying that this gets reverted just a few days before likely 5.19 release. I dare to say that if there were proper testing, this even shouldn't have landed in something that's called "rc1".

[Laser]

Really worrying that this gets reverted just a few days before likely 5.19 release. I dare to say that if there were proper testing, this even shouldn't have landed in something that's called "rc1".

? When do you think reverting a change that affects only a few users would be better? The RCs have a wide enough audience to catch this kind of stuff.

[aufkrawall]

The RCs have a wide enough audience to catch this kind of stuff.

There are usually a number of users reporting such things during RC phase, but that doesn't mean the seriousness of such issues is acknowledged accordingly by maintainers before things are declared stable. Also seen stuff breaking seriously in an obvious manner in drm-next and it was still that way at least several RCs later.

Of course, in Windows world drivers break terribly too (i.e. recent Nvidia 516.xx branch drivers regressed like crazy), but at least I can just revert that alpha software and stick with the regular kernel with patched vulnerabilities etc...

[agd5f]

The issue only affected some users and it was not discovered until rc1. The goal was to fix it before 5.19 final, and the root cause was eventually found, but we decided it was safer to just revert the change since it was so late in the cycle that there was not enough time left to make sure the issue was fully fixed. It will be re-enabled in 5.20 with the fix.

[aufkrawall]

Thanks, despite me notoriously being grumpy about breakage, I still really appreciate the insights you provide us with!

[smitty3268]

Really worrying that this gets reverted just a few days before likely 5.19 release. I dare to say that if there were proper testing, this even shouldn't have landed in something that's called "rc1".

The kernel "release candidates" have never actually been real release candidates. Linus just abuses that name for whatever reason.

The first couple rc's are alphas, the next 3 or so are betas, and then the last couple are actual release candidates.

[FireBurn]

I reported issues with it *way* before rc1, when it first landed in drm-misc, I'm not sure why an amdgpu feature went via misc rather than agd5f's tree
Arun luckily has fixed all the issues I was seeing, so it's a shame this is being reverted at the last possible point

[FireBurn]

https://gitlab.freedesktop.org/drm/amd/-/issues/1992