[PATCH] drm/amdgpu: add shared fdinfo stats

[Rob Clark]

On Tue, Nov 28, 2023 at 6:28 AM Alex Deucher <alexdeucher at gmail.com> wrote:
>
> On Tue, Nov 28, 2023 at 9:17 AM Christian König
> <ckoenig.leichtzumerken at gmail.com> wrote:
> >
> > Am 17.11.23 um 20:56 schrieb Alex Deucher:
> > > Add shared stats.  Useful for seeing shared memory.
> > >
> > > Signed-off-by: Alex Deucher <alexander.deucher at amd.com>
> > > ---
> > >   drivers/gpu/drm/amd/amdgpu/amdgpu_fdinfo.c |  4 ++++
> > >   drivers/gpu/drm/amd/amdgpu/amdgpu_object.c | 11 +++++++++++
> > >   drivers/gpu/drm/amd/amdgpu/amdgpu_object.h |  6 ++++++
> > >   3 files changed, 21 insertions(+)
> > >
> > > diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_fdinfo.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_fdinfo.c
> > > index 5706b282a0c7..c7df7fa3459f 100644
> > > --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_fdinfo.c
> > > +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_fdinfo.c
> > > @@ -97,6 +97,10 @@ void amdgpu_show_fdinfo(struct drm_printer *p, struct drm_file *file)
> > >                  stats.requested_visible_vram/1024UL);
> > >       drm_printf(p, "amd-requested-gtt:\t%llu KiB\n",
> > >                  stats.requested_gtt/1024UL);
> > > +     drm_printf(p, "drm-shared-vram:\t%llu KiB\n", stats.vram_shared/1024UL);
> > > +     drm_printf(p, "drm-shared-gtt:\t%llu KiB\n", stats.gtt_shared/1024UL);
> > > +     drm_printf(p, "drm-shared-cpu:\t%llu KiB\n", stats.cpu_shared/1024UL);
> > > +
> > >       for (hw_ip = 0; hw_ip < AMDGPU_HW_IP_NUM; ++hw_ip) {
> > >               if (!usage[hw_ip])
> > >                       continue;
> > > diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
> > > index d79b4ca1ecfc..c24f7b2c04c1 100644
> > > --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
> > > +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
> > > @@ -1287,25 +1287,36 @@ void amdgpu_bo_get_memory(struct amdgpu_bo *bo,
> > >                         struct amdgpu_mem_stats *stats)
> > >   {
> > >       uint64_t size = amdgpu_bo_size(bo);
> > > +     struct drm_gem_object *obj;
> > >       unsigned int domain;
> > > +     bool shared;
> > >
> > >       /* Abort if the BO doesn't currently have a backing store */
> > >       if (!bo->tbo.resource)
> > >               return;
> > >
> > > +     obj = &bo->tbo.base;
> > > +     shared = obj->handle_count > 1;
> >
> > Interesting approach but I don't think that this is correct.
> >
> > The handle_count is basically how many GEM handles are there for BO, so
> > for example it doesn't catch sharing things with V4L.
> >
> > What we should probably rather do is to take a look if
> > bo->tbo.base.dma_buf is NULL or not.
>
> +Rob, dri-devel
>
> This is what the generic drm helper code does.  See
> drm_show_memory_stats().  If that is not correct that code should
> probably be fixed too.

OTOH, v4l doesn't expose fdinfo.  What "shared" is telling you is
whether the BO is counted multiple times when you look at all
processes fdinfo.

But I guess it would be ok to look for obj->handle_count > 1 || obj->dma_buf

BR,
-R

>
> Alex
>
> >
> > Regards,
> > Christian.
> >
> >
> > > +
> > >       domain = amdgpu_mem_type_to_domain(bo->tbo.resource->mem_type);
> > >       switch (domain) {
> > >       case AMDGPU_GEM_DOMAIN_VRAM:
> > >               stats->vram += size;
> > >               if (amdgpu_bo_in_cpu_visible_vram(bo))
> > >                       stats->visible_vram += size;
> > > +             if (shared)
> > > +                     stats->vram_shared += size;
> > >               break;
> > >       case AMDGPU_GEM_DOMAIN_GTT:
> > >               stats->gtt += size;
> > > +             if (shared)
> > > +                     stats->gtt_shared += size;
> > >               break;
> > >       case AMDGPU_GEM_DOMAIN_CPU:
> > >       default:
> > >               stats->cpu += size;
> > > +             if (shared)
> > > +                     stats->cpu_shared += size;
> > >               break;
> > >       }
> > >
> > > diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.h
> > > index d28e21baef16..0503af75dc26 100644
> > > --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.h
> > > +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.h
> > > @@ -138,12 +138,18 @@ struct amdgpu_bo_vm {
> > >   struct amdgpu_mem_stats {
> > >       /* current VRAM usage, includes visible VRAM */
> > >       uint64_t vram;
> > > +     /* current shared VRAM usage, includes visible VRAM */
> > > +     uint64_t vram_shared;
> > >       /* current visible VRAM usage */
> > >       uint64_t visible_vram;
> > >       /* current GTT usage */
> > >       uint64_t gtt;
> > > +     /* current shared GTT usage */
> > > +     uint64_t gtt_shared;
> > >       /* current system memory usage */
> > >       uint64_t cpu;
> > > +     /* current shared system memory usage */
> > > +     uint64_t cpu_shared;
> > >       /* sum of evicted buffers, includes visible VRAM */
> > >       uint64_t evicted_vram;
> > >       /* sum of evicted buffers due to CPU access */
> >