Re: [PATCHv6 02/17] mm: Change the interface of prep_compound_tail()

["David Hildenbrand (arm)" <david@kernel.org>]

On 2/5/26 12:35, Kiryl Shutsemau wrote:
> On Wed, Feb 04, 2026 at 05:14:12PM +0100, David Hildenbrand (arm) wrote:
>> On 2/2/26 16:56, Kiryl Shutsemau wrote:
>>> Instead of passing down the head page and tail page index, pass the tail
>>> and head pages directly, as well as the order of the compound page.
>>>
>>> This is a preparation for changing how the head position is encoded in
>>> the tail page.
>>>
>>> Signed-off-by: Kiryl Shutsemau <kas@kernel.org>
>>> Reviewed-by: Muchun Song <muchun.song@linux.dev>
>>> Reviewed-by: Zi Yan <ziy@nvidia.com>
>>> ---
>>>    include/linux/page-flags.h |  4 +++-
>>>    mm/hugetlb.c               |  8 +++++---
>>>    mm/internal.h              | 12 ++++++------
>>>    mm/mm_init.c               |  2 +-
>>>    mm/page_alloc.c            |  2 +-
>>>    5 files changed, 16 insertions(+), 12 deletions(-)
>>>
>>> diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h
>>> index f7a0e4af0c73..8a3694369e15 100644
>>> --- a/include/linux/page-flags.h
>>> +++ b/include/linux/page-flags.h
>>> @@ -865,7 +865,9 @@ static inline bool folio_test_large(const struct folio *folio)
>>>    	return folio_test_head(folio);
>>>    }
>>> -static __always_inline void set_compound_head(struct page *page, struct page *head)
>>> +static __always_inline void set_compound_head(struct page *page,
>>> +					      const struct page *head,
>>> +					      unsigned int order)
>>
>> Two tab indents please on second+ parameter list whenever you touch code.
> 
> Do we have this coding style preference written down somewhere?

Good question. I assume not. But it's what we do in MM :)

> 
> -tip tree wants the opposite. Documentation/process/maintainer-tip.rst:
> 
> 	When splitting function declarations or function calls, then please align
> 	the first argument in the second line with the first argument in the first
> 	line::
> 
> I want the editor to do The Right Thing™ without my brain involvement.
> Having different coding styles in different corners of the kernel makes
> it hard.

Yeah, but unavoidable. :)

-- 
Cheers,

David