Re: [PATCH] mm: eliminate "expecting prototype" kernel-doc warnings

From: Matthew Wilcox
Date: Sun Apr 11 2021 - 14:50:27 EST


On Sun, Apr 11, 2021 at 10:43:21AM -0700, Randy Dunlap wrote:
> +++ linux-next-20210409/mm/mmu_gather.c
> @@ -250,7 +250,7 @@ void tlb_flush_mmu(struct mmu_gather *tl
> }
>
> /**
> - * tlb_gather_mmu - initialize an mmu_gather structure for page-table tear-down
> + * __tlb_gather_mmu - initialize an mmu_gather structure for page-table tear-down
> * @tlb: the mmu_gather structure to initialize
> * @mm: the mm_struct of the target address space
> * @fullmm: @mm is without users and we're going to destroy the full address

I think this is the wrong fix. __tlb_gather_mmu is static, so documenting
it isn't going to do much good. Instead, this doc should be moved
down to tlb_gather_mmu(). For bonus points, add documentation for
tlb_gather_mmu_fullmm().

> --- linux-next-20210409.orig/mm/oom_kill.c
> +++ linux-next-20210409/mm/oom_kill.c
> @@ -171,10 +171,11 @@ static bool oom_unkillable_task(struct t
> }
>
> /**
> - * Check whether unreclaimable slab amount is greater than
> - * all user memory(LRU pages).
> + * should_dump_unreclaim_slab - Check whether unreclaimable slab amount
> + * is greater than all user memory (LRU pages).
> + *
> * dump_unreclaimable_slab() could help in the case that
> - * oom due to too much unreclaimable slab used by kernel.
> + * oom is due to too much unreclaimable slab used by kernel.
> */
> static bool should_dump_unreclaim_slab(void)

This is static. I'd just remove the second '*' and turn it into a
non-kernel-doc comment.

> {
> --- linux-next-20210409.orig/mm/shuffle.c
> +++ linux-next-20210409/mm/shuffle.c
> @@ -148,7 +148,7 @@ void __meminit __shuffle_zone(struct zon
> }
>
> /**
> - * shuffle_free_memory - reduce the predictability of the page allocator
> + * __shuffle_free_memory - reduce the predictability of the page allocator
> * @pgdat: node page data
> */
> void __meminit __shuffle_free_memory(pg_data_t *pgdat)

Nobody calls __shuffle_free_memory() directly. If anything, the doc
should be moved to shuffle_free_memory(). But since it has precisely
one caller, and it's within mm/, I'm more inclined to leave this comment
where it is and turn it into a non-kernel-doc comment. Thoughts?