[PATCH v1] mm: gup: add forward declaration for try_grab_folio_fast

[PATCH v1] mm: gup: add forward declaration for try_grab_folio_fast

[Zhao Mengmeng]

try_grab_folio_fast() was used in gup_hugepte(), while itself was
defined after gup_hugepte(), so add a forward declaration to eliminate
the -Wimplicit-function-declaration warning.

Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202407010039.D3sIu3fu-lkp@intel.com/
Signed-off-by: Zhao Mengmeng <zhaomengmeng@kylinos.cn>
---
 mm/gup.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/mm/gup.c b/mm/gup.c
index 7439359d0b71..222b83a87d7d 100644
--- a/mm/gup.c
+++ b/mm/gup.c
@@ -488,6 +488,9 @@ static unsigned long hugepte_addr_end(unsigned long addr, unsigned long end,
 	return (__boundary - 1 < end - 1) ? __boundary : end;
 }
 
+static struct folio *try_grab_folio_fast(struct page *page, int refs,
+					 unsigned int flags);
+
 /*
  * Returns 1 if succeeded, 0 if failed, -EMLINK if unshare needed.
  *
-- 
2.33.0

Re: [PATCH v1] mm: gup: add forward declaration for try_grab_folio_fast

[David Hildenbrand]

On 01.07.24 05:40, Zhao Mengmeng wrote:
> try_grab_folio_fast() was used in gup_hugepte(), while itself was
> defined after gup_hugepte(), so add a forward declaration to eliminate
> the -Wimplicit-function-declaration warning.
> 
> Reported-by: kernel test robot <lkp@intel.com>
> Closes: https://lore.kernel.org/oe-kbuild-all/202407010039.D3sIu3fu-lkp@intel.com/
> Signed-off-by: Zhao Mengmeng <zhaomengmeng@kylinos.cn>
> ---
>   mm/gup.c | 3 +++
>   1 file changed, 3 insertions(+)
> 
> diff --git a/mm/gup.c b/mm/gup.c
> index 7439359d0b71..222b83a87d7d 100644
> --- a/mm/gup.c
> +++ b/mm/gup.c
> @@ -488,6 +488,9 @@ static unsigned long hugepte_addr_end(unsigned long addr, unsigned long end,
>   	return (__boundary - 1 < end - 1) ? __boundary : end;
>   }
>   
> +static struct folio *try_grab_folio_fast(struct page *page, int refs,
> +					 unsigned int flags);
> +

This function should really be called "gup_fast_", just like all other 
gup_fast_ specific functions. I might send some follow-up cleanups later.

-- 
Cheers,

David / dhildenb

Re: [PATCH v1] mm: gup: add forward declaration for try_grab_folio_fast

[Zhao Mengmeng]

On 2024/7/1 15:16, David Hildenbrand wrote:
> On 01.07.24 05:40, Zhao Mengmeng wrote:
>> try_grab_folio_fast() was used in gup_hugepte(), while itself was
>> defined after gup_hugepte(), so add a forward declaration to eliminate
>> the -Wimplicit-function-declaration warning.
>>
>> Reported-by: kernel test robot <lkp@intel.com>
>> Closes:
>> https://lore.kernel.org/oe-kbuild-all/202407010039.D3sIu3fu-lkp@intel.com/
>> Signed-off-by: Zhao Mengmeng <zhaomengmeng@kylinos.cn>
>> ---
>>   mm/gup.c | 3 +++
>>   1 file changed, 3 insertions(+)
>>
>> diff --git a/mm/gup.c b/mm/gup.c
>> index 7439359d0b71..222b83a87d7d 100644
>> --- a/mm/gup.c
>> +++ b/mm/gup.c
>> @@ -488,6 +488,9 @@ static unsigned long hugepte_addr_end(unsigned
>> long addr, unsigned long end,
>>       return (__boundary - 1 < end - 1) ? __boundary : end;
>>   }
>>   +static struct folio *try_grab_folio_fast(struct page *page, int refs,
>> +                     unsigned int flags);
>> +
>
> This function should really be called "gup_fast_", just like all other
> gup_fast_ specific functions. I might send some follow-up cleanups later.
>
Yeah, looking forward to your patch. Besides, I have seen Yang's fix in

https://lore.kernel.org/linux-mm/CAHbLzkowMSso-4Nufc9hcMehQsK9PNz3OSu-+eniU-2Mm-xjhA@mail.gmail.com/T/#m7ff03bf88814d8352052fbd8a1c90fee0ba5b576

and it is better. So sorry to bother you all.