On 2/7/23 14:30, Pekka Paalanen wrote: > On Mon, 23 Jan 2023 21:38:11 +0100 > Christian König <christian.koenig@xxxxxxx> wrote: >> Am 23.01.23 um 21:26 schrieb André Almeida: >>> >>> diff --git a/Documentation/gpu/drm-reset.rst b/Documentation/gpu/drm-reset.rst >>> new file mode 100644 >>> index 000000000000..0dd11a469cf9 >>> --- /dev/null >>> +++ b/Documentation/gpu/drm-reset.rst >>> @@ -0,0 +1,51 @@ >>> +================ >>> +DRM Device Reset >>> +================ >>> + >>> +The GPU stack is really complex and is prone to errors, from hardware bugs, >>> +faulty applications and everything in the many layers in between. To recover >>> +from this kind of state, sometimes is needed to reset the GPU. Unproper handling >>> +of GPU resets can lead to an unstable userspace. This page describes what's the >>> +expected behaviour from DRM drivers to do in those situations, from usermode >>> +drivers and compositors as well. >>> + >>> +Robustness >>> +---------- >>> + >>> +First of all, application robust APIs, when available, should be used. This >>> +allows the application to correctly recover and continue to run after a reset. >>> +Apps that doesn't use this should be promptly killed when the kernel driver >>> +detects that it's in broken state. Specifically guidelines for some APIs: >>> + >> >>> +- OpenGL: During a reset, KMD kill processes that haven't ARB Robustness >>> + enabled, assuming they can't recover. >> >> This is a pretty clear NAK from my side to this approach. The KMD should >> never mess with an userspace process directly in such a way. >> >> Instead use something like this "OpenGL: KMD signals the abortion of >> submitted commands and the UMD should then react accordingly and abort >> the application.". > > what Christian said, plus I would not assume that robust programs will > always respond by creating a new context. They could also switch > to a software renderer, [...] That is indeed what Firefox does. -- Earthling Michel Dänzer | https://redhat.com Libre software enthusiast | Mesa and Xwayland developer
