Re: [PATCH 12/17] ttm: add objcg pointer to bo and tt

["Christian König" <christian.koenig@amd.com>]

On 30.06.25 06:49, Dave Airlie wrote:
> From: Dave Airlie <airlied@redhat.com>
> 
> This just adds the obj cgroup pointer to the bo and tt structs,
> and sets it between them.
> 
> Signed-off-by: Dave Airlie <airlied@redhat.com>
> ---
>  drivers/gpu/drm/ttm/ttm_tt.c | 1 +
>  include/drm/ttm/ttm_bo.h     | 6 ++++++
>  include/drm/ttm/ttm_tt.h     | 2 ++
>  3 files changed, 9 insertions(+)
> 
> diff --git a/drivers/gpu/drm/ttm/ttm_tt.c b/drivers/gpu/drm/ttm/ttm_tt.c
> index 8f38de3b2f1c..0c54d5e2bfdd 100644
> --- a/drivers/gpu/drm/ttm/ttm_tt.c
> +++ b/drivers/gpu/drm/ttm/ttm_tt.c
> @@ -162,6 +162,7 @@ static void ttm_tt_init_fields(struct ttm_tt *ttm,
>  	ttm->caching = caching;
>  	ttm->restore = NULL;
>  	ttm->backup = NULL;
> +	ttm->objcg = bo->objcg;
>  }
>  
>  int ttm_tt_init(struct ttm_tt *ttm, struct ttm_buffer_object *bo,
> diff --git a/include/drm/ttm/ttm_bo.h b/include/drm/ttm/ttm_bo.h
> index 099dc2604baa..f26ec0a0273f 100644
> --- a/include/drm/ttm/ttm_bo.h
> +++ b/include/drm/ttm/ttm_bo.h
> @@ -135,6 +135,12 @@ struct ttm_buffer_object {
>  	 * reservation lock.
>  	 */
>  	struct sg_table *sg;
> +
> +	/**
> +	 * @objcg: object cgroup to charge this to if it ends up using system memory.
> +	 * NULL means don't charge.
> +	 */
> +	struct obj_cgroup *objcg;
>  };
>  
>  #define TTM_BO_MAP_IOMEM_MASK 0x80
> diff --git a/include/drm/ttm/ttm_tt.h b/include/drm/ttm/ttm_tt.h
> index 15d4019685f6..c13fea4c2915 100644
> --- a/include/drm/ttm/ttm_tt.h
> +++ b/include/drm/ttm/ttm_tt.h
> @@ -126,6 +126,8 @@ struct ttm_tt {
>  	enum ttm_caching caching;
>  	/** @restore: Partial restoration from backup state. TTM private */
>  	struct ttm_pool_tt_restore *restore;
> +	/** @objcg: Object cgroup for this TT allocation */
> +	struct obj_cgroup *objcg;
>  };

We should probably keep that out of the pool and account the memory to the BO instead.

Regards,
Christian.

>  
>  /**