Re: [PATCH v2 0/7] kernel/cgroups: Add "dmem" memory accounting cgroup.

[Friedrich Vock <friedrich.vock@gmx.de>]

Hi,

On 04.12.24 14:44, Maarten Lankhorst wrote:
> New update. Instead of calling it the 'dev' cgroup, it's now the 'dmem' cgroup.

Thanks! I think this version looks pretty good.

>
> Because it only deals with memory regions, the UAPI has been updated to use dmem.min/low/max/current, and to make the API cleaner, the names are changed too.
>
> dmem.current could contain a line like:
> "drm/0000:03:00.0/vram0 1073741824"
>
> But I think using "drm/card0/vram0" instead of PCIID would perhaps be good too. I'm open to changing it to that based on feedback.

Agree, allowing userspace to reference DRM devices via "cardN" syntax
sounds good. What about other subsystems potentially using dmem cgroups?
I'm not familiar with the media subsystem, but I imagine we might be
dealing with things like USB devices there? Is something like a
"deviceN" possible there as well, or would device IDs look completely
different?

Regards,
Friedrich

>
> I've created an IGT test for min and max, and found the changes
> from Friedrich Vock sent as feedback were needed.
> I've integrated those into the first patch.
>
> Maarten Lankhorst (5):
>    kernel/cgroup: Add "dmem" memory accounting cgroup
>    drm/ttm: Handle cgroup based eviction in TTM
>    drm/xe: Implement cgroup for vram
>    drm/amdgpu: Add cgroups implementation
>    drm/xe: Hack to test with mapped pages instead of vram.
>
> Maxime Ripard (2):
>    drm/drv: Add drmm managed registration helper for dmem cgroups.
>    drm/gem: Add cgroup memory accounting for VRAM helper.
>
>   Documentation/admin-guide/cgroup-v2.rst       |  58 +-
>   Documentation/core-api/cgroup.rst             |   9 +
>   Documentation/core-api/index.rst              |   1 +
>   Documentation/gpu/drm-compute.rst             |  54 ++
>   drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c  |   4 +
>   drivers/gpu/drm/drm_drv.c                     |  32 +
>   drivers/gpu/drm/drm_gem_vram_helper.c         |  15 +-
>   drivers/gpu/drm/ttm/tests/ttm_bo_test.c       |  18 +-
>   .../gpu/drm/ttm/tests/ttm_bo_validate_test.c  |   4 +-
>   drivers/gpu/drm/ttm/tests/ttm_resource_test.c |   2 +-
>   drivers/gpu/drm/ttm/ttm_bo.c                  |  54 +-
>   drivers/gpu/drm/ttm/ttm_resource.c            |  23 +-
>   drivers/gpu/drm/xe/xe_ttm_sys_mgr.c           |   5 +
>   drivers/gpu/drm/xe/xe_ttm_vram_mgr.c          |   8 +
>   include/drm/drm_drv.h                         |   5 +
>   include/drm/ttm/ttm_resource.h                |  12 +-
>   include/linux/cgroup_dmem.h                   |  67 ++
>   include/linux/cgroup_subsys.h                 |   4 +
>   include/linux/page_counter.h                  |   2 +-
>   init/Kconfig                                  |  10 +
>   kernel/cgroup/Makefile                        |   1 +
>   kernel/cgroup/dmem.c                          | 861 ++++++++++++++++++
>   mm/page_counter.c                             |   4 +-
>   23 files changed, 1219 insertions(+), 34 deletions(-)
>   create mode 100644 Documentation/core-api/cgroup.rst
>   create mode 100644 Documentation/gpu/drm-compute.rst
>   create mode 100644 include/linux/cgroup_dmem.h
>   create mode 100644 kernel/cgroup/dmem.c
>