On Tue, 12 Sep 2023 09:36:57 +0100
Adrián Larumbe <adrian.larumbe@xxxxxxxxxxxxx> wrote:
> A new DRM GEM object function is added so that drm_show_memory_stats can
> provide more accurate memory usage numbers.
>
> Ideally, in panfrost_gem_status, the BO's purgeable flag would be checked
> after locking the driver's shrinker mutex, but drm_show_memory_stats takes
> over the drm file's object handle database spinlock, so there's potential
> for a race condition here.
>
> Signed-off-by: Adrián Larumbe <adrian.larumbe@xxxxxxxxxxxxx>
Reviewed-by: Boris Brezillon <boris.brezillon@xxxxxxxxxxxxx>
> ---
> drivers/gpu/drm/panfrost/panfrost_drv.c | 2 ++
> drivers/gpu/drm/panfrost/panfrost_gem.c | 14 ++++++++++++++
> 2 files changed, 16 insertions(+)
>
> diff --git a/drivers/gpu/drm/panfrost/panfrost_drv.c b/drivers/gpu/drm/panfrost/panfrost_drv.c
> index 2d9c115821a7..e71a89a283cd 100644
> --- a/drivers/gpu/drm/panfrost/panfrost_drv.c
> +++ b/drivers/gpu/drm/panfrost/panfrost_drv.c
> @@ -567,6 +567,8 @@ static void panfrost_show_fdinfo(struct drm_printer *p, struct drm_file *file)
> struct panfrost_device *pfdev = dev->dev_private;
>
> panfrost_gpu_show_fdinfo(pfdev, file->driver_priv, p);
> +
> + drm_show_memory_stats(p, file);
> }
>
> static const struct file_operations panfrost_drm_driver_fops = {
> diff --git a/drivers/gpu/drm/panfrost/panfrost_gem.c b/drivers/gpu/drm/panfrost/panfrost_gem.c
> index 3c812fbd126f..7d8f83d20539 100644
> --- a/drivers/gpu/drm/panfrost/panfrost_gem.c
> +++ b/drivers/gpu/drm/panfrost/panfrost_gem.c
> @@ -195,6 +195,19 @@ static int panfrost_gem_pin(struct drm_gem_object *obj)
> return drm_gem_shmem_pin(&bo->base);
> }
>
> +static enum drm_gem_object_status panfrost_gem_status(struct drm_gem_object *obj)
> +{
> + struct panfrost_gem_object *bo = to_panfrost_bo(obj);
> + enum drm_gem_object_status res = 0;
> +
> + res |= (bo->base.madv == PANFROST_MADV_DONTNEED) ?
> + DRM_GEM_OBJECT_PURGEABLE : 0;
> +
> + res |= (bo->base.pages) ? DRM_GEM_OBJECT_RESIDENT : 0;
> +
> + return res;
> +}
> +
> static const struct drm_gem_object_funcs panfrost_gem_funcs = {
> .free = panfrost_gem_free_object,
> .open = panfrost_gem_open,
> @@ -206,6 +219,7 @@ static const struct drm_gem_object_funcs panfrost_gem_funcs = {
> .vmap = drm_gem_shmem_object_vmap,
> .vunmap = drm_gem_shmem_object_vunmap,
> .mmap = drm_gem_shmem_object_mmap,
> + .status = panfrost_gem_status,
> .vm_ops = &drm_gem_shmem_vm_ops,
> };
>
