Hello all! I would like to propose a new API for allowing processes to control the priority of GPU queues similar to RLIMIT_NICE/RLIMIT_RTPRIO. The main reason for this is for compositors such as Gamescope and SteamVR vrcompositor to be able to create realtime async compute queues on AMD without the need of CAP_SYS_NICE. The current situation is bad for a few reasons, one being that in order to setcap the executable, typically one must run as root which involves a pretty high privelage escalation in order to achieve one small feat, a realtime async compute queue queue for VR or a compositor. The executable cannot be setcap'ed inside a container nor can the setcap'ed executable be run in a container with NO_NEW_PRIVS. I go into more detail in the description in `uapi: Add RLIMIT_GPUPRIO`. My initial proposal here is to add a new RLIMIT, `RLIMIT_GPUPRIO`, which seems to make most initial sense to me to solve the problem. I am definitely not set that this is the best formulation however or if this should be linked to DRM (in terms of it's scheduler priority enum/definitions) in any way and and would really like other people's opinions across the stack on this. Once initial concern is that potentially this RLIMIT could out-live the lifespan of DRM. It sounds crazy saying it right now, something that definitely popped into my mind when touching `resource.h`. :-) Anyway, please let me know what you think! Definitely open to any feedback and advice you may have. :D Thanks! - Joshie Joshua Ashton (4): drm/scheduler: Add DRM_SCHED_PRIORITY_VERY_HIGH drm/scheduler: Split out drm_sched_priority to own file uapi: Add RLIMIT_GPUPRIO drm/amd/amdgpu: Check RLIMIT_GPUPRIO in priority permissions drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.c | 13 ++++++-- drivers/gpu/drm/msm/msm_gpu.h | 2 +- fs/proc/base.c | 1 + include/asm-generic/resource.h | 3 +- include/drm/drm_sched_priority.h | 41 +++++++++++++++++++++++++ include/drm/gpu_scheduler.h | 14 +-------- include/uapi/asm-generic/resource.h | 3 +- 7 files changed, 58 insertions(+), 19 deletions(-) create mode 100644 include/drm/drm_sched_priority.h -- 2.40.0
