On Sat, 5 Jun 2021 15:51:40 +0800 Miaohe Lin <linmiaohe@xxxxxxxxxx> wrote:
> Since commit 9d8c5b5284e4 ("mm: zbud: fix condition check on allocation
> size"), zbud_pool.unbuddied[0] is always unused. We can reuse it as buddied
> field to save some possible memory.
>
> ...
>
> --- a/mm/zbud.c
> +++ b/mm/zbud.c
> @@ -96,7 +96,7 @@
> struct zbud_pool {
> spinlock_t lock;
> struct list_head unbuddied[NCHUNKS];
> - struct list_head buddied;
> +#define buddied unbuddied[0]
> struct list_head lru;
> u64 pages_nr;
> const struct zbud_ops *ops;
That looks a bit hacky. Can we at least have a comment explaining
what's going on?
Would it be better to implement this with a union, rather than a #define?
