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

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

[Randy Dunlap]

Fix stray kernel-doc warnings in mm/ due to mis-typed or missing
function names.

Quietens these kernel-doc warnings:

../mm/mmu_gather.c:264: warning: expecting prototype for tlb_gather_mmu(). Prototype was for __tlb_gather_mmu() instead
../mm/oom_kill.c:180: warning: expecting prototype for Check whether unreclaimable slab amount is greater than(). Prototype was for should_dump_unreclaim_slab() instead
../mm/shuffle.c:155: warning: expecting prototype for shuffle_free_memory(). Prototype was for __shuffle_free_memory() instead

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: linux-mm@kvack.org
---
 mm/mmu_gather.c |    2 +-
 mm/oom_kill.c   |    7 ++++---
 mm/shuffle.c    |    2 +-
 3 files changed, 6 insertions(+), 5 deletions(-)

--- linux-next-20210409.orig/mm/mmu_gather.c
+++ 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
--- 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)
 {
--- 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)

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

[Matthew Wilcox]

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?

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

[Randy Dunlap]

On 4/11/21 11:35 AM, Matthew Wilcox wrote:
> 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().

I'll certainly add the doc for tlb_gather_mmu_fullmm()  -- don't want to
lose that @fullmm: comment.

> 
>> --- 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.

Done.

>>  {
>> --- 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?
> 

Sounds good. Thanks. v2 coming soon.

-- 
~Randy