Re: [PATCH v2 1/3] drm/fdinfo: Add "evicted" memory accounting

[Steven Price <steven.price@arm.com>]

On 21/04/2026 11:45, Nicolas Frattaroli wrote:
> Currently, there's no way to know for certain how much GPU memory was
> swapped out. The difference between total and resident memory would
> include newly allocated pages, which are not resident, but also aren't
> swapped out.
> 
> Add a new drm_gem_object_status so drivers can signal when an object has
> been evicted to swap, and add a new "evicted" counter to
> drm_memory_stats.
> 
> Due to how the supported_flags bitmask is determined, the "evicted"
> count won't be printed to fdinfo if there's no swapped out pages.
> 
> Signed-off-by: Nicolas Frattaroli <nicolas.frattaroli@collabora.com>

You should also update the documentation to include this new field
(Documentation/gpu/drm-usage-stats.rst).

Thanks,
Steve

> ---
>  drivers/gpu/drm/drm_file.c | 8 ++++++++
>  include/drm/drm_file.h     | 2 ++
>  include/drm/drm_gem.h      | 2 ++
>  3 files changed, 12 insertions(+)
> 
> diff --git a/drivers/gpu/drm/drm_file.c b/drivers/gpu/drm/drm_file.c
> index ec820686b302..5078172976c0 100644
> --- a/drivers/gpu/drm/drm_file.c
> +++ b/drivers/gpu/drm/drm_file.c
> @@ -868,6 +868,7 @@ int drm_memory_stats_is_zero(const struct drm_memory_stats *stats)
>  		stats->private == 0 &&
>  		stats->resident == 0 &&
>  		stats->purgeable == 0 &&
> +		stats->evicted == 0 &&
>  		stats->active == 0);
>  }
>  EXPORT_SYMBOL(drm_memory_stats_is_zero);
> @@ -901,6 +902,10 @@ void drm_print_memory_stats(struct drm_printer *p,
>  	if (supported_status & DRM_GEM_OBJECT_PURGEABLE)
>  		drm_fdinfo_print_size(p, prefix, "purgeable", region,
>  				      stats->purgeable);
> +
> +	if (supported_status & DRM_GEM_OBJECT_EVICTED)
> +		drm_fdinfo_print_size(p, prefix, "evicted", region,
> +				      stats->evicted);
>  }
>  EXPORT_SYMBOL(drm_print_memory_stats);
>  
> @@ -954,6 +959,9 @@ void drm_show_memory_stats(struct drm_printer *p, struct drm_file *file)
>  
>  		if (s & DRM_GEM_OBJECT_PURGEABLE)
>  			status.purgeable += add_size;
> +
> +		if (s & DRM_GEM_OBJECT_EVICTED)
> +			status.evicted += add_size;
>  	}
>  	spin_unlock(&file->table_lock);
>  
> diff --git a/include/drm/drm_file.h b/include/drm/drm_file.h
> index 6ee70ad65e1f..213dfecac342 100644
> --- a/include/drm/drm_file.h
> +++ b/include/drm/drm_file.h
> @@ -500,6 +500,7 @@ void drm_send_event_timestamp_locked(struct drm_device *dev,
>   * @resident: Total size of GEM objects backing pages
>   * @purgeable: Total size of GEM objects that can be purged (resident and not active)
>   * @active: Total size of GEM objects active on one or more engines
> + * @evicted: Total size of GEM objects that have been evicted to swap
>   *
>   * Used by drm_print_memory_stats()
>   */
> @@ -509,6 +510,7 @@ struct drm_memory_stats {
>  	u64 resident;
>  	u64 purgeable;
>  	u64 active;
> +	u64 evicted;
>  };
>  
>  enum drm_gem_object_status;
> diff --git a/include/drm/drm_gem.h b/include/drm/drm_gem.h
> index 86f5846154f7..b42ea2e582cf 100644
> --- a/include/drm/drm_gem.h
> +++ b/include/drm/drm_gem.h
> @@ -53,6 +53,7 @@ struct drm_gem_object;
>   * @DRM_GEM_OBJECT_RESIDENT: object is resident in memory (ie. not unpinned)
>   * @DRM_GEM_OBJECT_PURGEABLE: object marked as purgeable by userspace
>   * @DRM_GEM_OBJECT_ACTIVE: object is currently used by an active submission
> + * @DRM_GEM_OBJECT_EVICTED: object is evicted to swap
>   *
>   * Bitmask of status used for fdinfo memory stats, see &drm_gem_object_funcs.status
>   * and drm_show_fdinfo().  Note that an object can report DRM_GEM_OBJECT_PURGEABLE
> @@ -67,6 +68,7 @@ enum drm_gem_object_status {
>  	DRM_GEM_OBJECT_RESIDENT  = BIT(0),
>  	DRM_GEM_OBJECT_PURGEABLE = BIT(1),
>  	DRM_GEM_OBJECT_ACTIVE    = BIT(2),
> +	DRM_GEM_OBJECT_EVICTED   = BIT(3),
>  };
>  
>  /**
>