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

[David Airlie <airlied@redhat.com>]

On Mon, Jun 30, 2025 at 8:24 PM Christian König
<christian.koenig@amd.com> wrote:
>
> 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.
>

I tried that like 2-3 patch posting iterations ago, you suggested it
then, it didn't work. It has to be done at the pool level, I think it
was due to swap handling.

Dave.