[Intel-gfx] [RFC 01/12] drm/i915: Expose list of clients in sysfs

[Chris Wilson]

Quoting Tvrtko Ursulin (2020-03-09 18:31:18)
> +struct i915_drm_client *
> +i915_drm_client_add(struct i915_drm_clients *clients, struct task_struct *task)
> +{
> +       struct i915_drm_client *client;
> +       int ret;
> +
> +       client = kzalloc(sizeof(*client), GFP_KERNEL);
> +       if (!client)
> +               return ERR_PTR(-ENOMEM);
> +
> +       kref_init(&client->kref);
> +       client->clients = clients;
> +
> +       ret = mutex_lock_interruptible(&clients->lock);
> +       if (ret)
> +               goto err_id;
> +       ret = xa_alloc_cyclic(&clients->xarray, &client->id, client,
> +                             xa_limit_32b, &clients->next_id, GFP_KERNEL);

So what's next_id used for that explains having the over-arching mutex?
-Chris