[PATCH 0/5] Add reclaim to the dmem cgroup controller

Thomas Hellström
2026-03-27T08:16:37Z

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 error propagation.
Patch 2 implements and documents a reclaim callback interface
for the dmem controller.
Patch 3 implements a TTM reclaim callback.
Patch 4-5 hooks up the reclaim callback to the dmem cgroups-
aware drivers xe and amdgpu.

Thomas Hellström (5):
cgroup/dmem: Return error when setting max below current usage
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 | 102 ++++++++++++++++---
10 files changed, 265 insertions(+), 27 deletions(-)

--
2.53.0