[PATCH v3 5/8] drm/panfrost: Add fdinfo support for memory stats

Adrián Larumbe
2023-09-05T19:02:16Z

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@collabora.com>
---
drivers/gpu/drm/panfrost/panfrost_drv.c | 1 +
drivers/gpu/drm/panfrost/panfrost_gem.c | 14 ++++++++++++++
2 files changed, 15 insertions(+)

diff --git a/drivers/gpu/drm/panfrost/panfrost_drv.c b/drivers/gpu/drm/panfrost/panfrost_drv.c
index 94787f4aee27..3de7e821ef23 100644
--- a/drivers/gpu/drm/panfrost/panfrost_drv.c
+++ b/drivers/gpu/drm/panfrost/panfrost_drv.c
@@ -574,6 +574,7 @@ static void panfrost_show_fdinfo(struct drm_printer *p, struct drm_file *file)

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,
};

--
2.42.0