Re: [PATCH wireless-next] wifi: mac80211: fold tid_ampdu_rx allocations into a flexible array

[Johannes Berg]

On Wed, 2026-06-03 at 17:14 -0700, Rosen Penev wrote:
> Convert the separately-allocated reorder_buf pointer to a C99 flexible
> array member at the end of struct tid_ampdu_rx, and place reorder_time
> in the same allocation immediately after it. This collapses three
> allocations into one and removes the corresponding kfree() pairs from
> the error and free paths.

As I pointed out before, I'm not a huge fan of these "doing a minor
improvement for the sake of it" contributions ...

> @@ -241,7 +241,6 @@ struct tid_ampdu_rx {
>  	struct rcu_head rcu_head;
>  	spinlock_t reorder_lock;
>  	u64 reorder_buf_filtered;
> -	struct sk_buff_head *reorder_buf;
>  	unsigned long *reorder_time;
>  	struct sta_info *sta;
>  	struct timer_list session_timer;
> @@ -256,6 +255,7 @@ struct tid_ampdu_rx {
>  	u8 auto_seq:1,
>  	   removed:1,
>  	   started:1;
> +	struct sk_buff_head reorder_buf[];

Given that sizeof(unsigned long) == sizeof(void *), that would probably
be far simpler as

	struct {
		struct sk_buf_head buf;
		unsigned long time;
	} reorder[];

or so.

johannes