Re: [PATCH 05/29] drm/panfrost: dynamically allocate the drm-panfrost shrinker

[Bobs_Email <robertharoldlee@gmail.com>]

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Please remove Bob Lee from this email group.
He is deceased


On Thu, Jun 22, 2023, 1:56 AM Qi Zheng <zhengqi.arch@bytedance.com> wrote:

> In preparation for implementing lockless slab shrink,
> we need to dynamically allocate the drm-panfrost shrinker,
> so that it can be freed asynchronously using kfree_rcu().
> Then it doesn't need to wait for RCU read-side critical
> section when releasing the struct panfrost_device.
>
> Signed-off-by: Qi Zheng <zhengqi.arch@bytedance.com>
> ---
>  drivers/gpu/drm/panfrost/panfrost_device.h    |  2 +-
>  .../gpu/drm/panfrost/panfrost_gem_shrinker.c  | 24 ++++++++++---------
>  2 files changed, 14 insertions(+), 12 deletions(-)
>
> diff --git a/drivers/gpu/drm/panfrost/panfrost_device.h
> b/drivers/gpu/drm/panfrost/panfrost_device.h
> index b0126b9fbadc..e667e5689353 100644
> --- a/drivers/gpu/drm/panfrost/panfrost_device.h
> +++ b/drivers/gpu/drm/panfrost/panfrost_device.h
> @@ -118,7 +118,7 @@ struct panfrost_device {
>
>         struct mutex shrinker_lock;
>         struct list_head shrinker_list;
> -       struct shrinker shrinker;
> +       struct shrinker *shrinker;
>
>         struct panfrost_devfreq pfdevfreq;
>  };
> diff --git a/drivers/gpu/drm/panfrost/panfrost_gem_shrinker.c
> b/drivers/gpu/drm/panfrost/panfrost_gem_shrinker.c
> index bf0170782f25..2a5513eb9e1f 100644
> --- a/drivers/gpu/drm/panfrost/panfrost_gem_shrinker.c
> +++ b/drivers/gpu/drm/panfrost/panfrost_gem_shrinker.c
> @@ -18,8 +18,7 @@
>  static unsigned long
>  panfrost_gem_shrinker_count(struct shrinker *shrinker, struct
> shrink_control *sc)
>  {
> -       struct panfrost_device *pfdev =
> -               container_of(shrinker, struct panfrost_device, shrinker);
> +       struct panfrost_device *pfdev = shrinker->private_data;
>         struct drm_gem_shmem_object *shmem;
>         unsigned long count = 0;
>
> @@ -65,8 +64,7 @@ static bool panfrost_gem_purge(struct drm_gem_object
> *obj)
>  static unsigned long
>  panfrost_gem_shrinker_scan(struct shrinker *shrinker, struct
> shrink_control *sc)
>  {
> -       struct panfrost_device *pfdev =
> -               container_of(shrinker, struct panfrost_device, shrinker);
> +       struct panfrost_device *pfdev = shrinker->private_data;
>         struct drm_gem_shmem_object *shmem, *tmp;
>         unsigned long freed = 0;
>
> @@ -100,10 +98,15 @@ panfrost_gem_shrinker_scan(struct shrinker *shrinker,
> struct shrink_control *sc)
>  void panfrost_gem_shrinker_init(struct drm_device *dev)
>  {
>         struct panfrost_device *pfdev = dev->dev_private;
> -       pfdev->shrinker.count_objects = panfrost_gem_shrinker_count;
> -       pfdev->shrinker.scan_objects = panfrost_gem_shrinker_scan;
> -       pfdev->shrinker.seeks = DEFAULT_SEEKS;
> -       WARN_ON(register_shrinker(&pfdev->shrinker, "drm-panfrost"));
> +
> +       pfdev->shrinker =
> shrinker_alloc_and_init(panfrost_gem_shrinker_count,
> +
>  panfrost_gem_shrinker_scan, 0,
> +                                                 DEFAULT_SEEKS, 0, pfdev);
> +       if (pfdev->shrinker &&
> +           register_shrinker(pfdev->shrinker, "drm-panfrost")) {
> +               shrinker_free(pfdev->shrinker);
> +               WARN_ON(1);
> +       }
>  }
>
>  /**
> @@ -116,7 +119,6 @@ void panfrost_gem_shrinker_cleanup(struct drm_device
> *dev)
>  {
>         struct panfrost_device *pfdev = dev->dev_private;
>
> -       if (pfdev->shrinker.nr_deferred) {
> -               unregister_shrinker(&pfdev->shrinker);
> -       }
> +       if (pfdev->shrinker->nr_deferred)
> +               unregister_and_free_shrinker(pfdev->shrinker);
>  }
> --
> 2.30.2
>
>

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