When writing a "max" limit lower than the current usage, the
existing code silently failed. This series aims to improve
on that by returning -EBUSY on failure and also attempt
to synchronously reclaim device memory to push the usage
under the new max limit to avoid the error.

Patch 1 implements and documents a reclaim callback interface
      for the dmem controller.
Patch 2 implements a TTM reclaim callback.
Patch 3-4 hooks up the reclaim callback to the dmem cgroups-
      aware drivers xe and amdgpu.

v2:
- Remove the error propagation that was in a previous series (Maarten)
- A number of updates in patch 1. See its commit message for
  details (Maarten)

User-space tests are at
https://patchwork.freedesktop.org/series/163935/

Test-with: 20260428065411.4222-1-thomas.hellstrom@linux.intel.com

Thomas Hellström (4):
  cgroup/dmem: Add reclaim callback for lowering max below current usage
  drm/ttm: Hook up a cgroup-aware reclaim callback for the dmem
    controller
  drm/xe: Wire up dmem cgroup reclaim for VRAM manager
  drm/amdgpu: Wire up dmem cgroup reclaim for VRAM manager

 drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c      |  2 +-
 drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c | 10 ++-
 drivers/gpu/drm/ttm/ttm_bo.c                 | 95 +++++++++++++++++++-
 drivers/gpu/drm/ttm/ttm_bo_util.c            |  3 +-
 drivers/gpu/drm/ttm/ttm_resource.c           | 36 ++++++++
 drivers/gpu/drm/xe/xe_ttm_vram_mgr.c         | 19 ++--
 include/drm/ttm/ttm_bo.h                     | 10 +++
 include/drm/ttm/ttm_resource.h               |  4 +
 include/linux/cgroup_dmem.h                  | 11 +++
 kernel/cgroup/dmem.c                         | 83 +++++++++++++++--
 10 files changed, 249 insertions(+), 24 deletions(-)

-- 
2.53.0