On 11/18/22 20:10, Bagas Sanjaya wrote:
> Greetings,
>
> I found a new htmldocs warning on mm-everything:
>
> WARNING: kernel-doc './scripts/kernel-doc -rst -enable-lineno -sphinx-version 2.4.4 -internal ./include/linux/mm_types.h' failed with return code 1
>
> Checking the header with './scripts/kernel-doc -v -none
> ./include/linux/mm_types.h', I got the full error:
>
> include/linux/mm_types.h:255: info: Scanning doc for struct encoded_page
> include/linux/mm_types.h:268: error: Cannot parse struct or union!
> include/linux/mm_types.h:287: info: Scanning doc for struct folio
> include/linux/mm_types.h:917: info: Scanning doc for typedef vm_fault_t
> include/linux/mm_types.h:924: info: Scanning doc for enum vm_fault_reason
> include/linux/mm_types.h:1028: info: Scanning doc for enum fault_flag
> 1 errors
>
> The culprit is encoded_page struct, which is null struct (nonexistent type)
> with kernel-doc comments:
>
> /**
> * struct encoded_page - a nonexistent type marking this pointer
> *
> * An 'encoded_page' pointer is a pointer to a regular 'struct page', but
> * with the low bits of the pointer indicating extra context-dependent
> * information. Not super-common, but happens in mmu_gather and mlock
> * handling, and this acts as a type system check on that use.
> *
> * We only really have two guaranteed bits in general, although you could
> * play with 'struct page' alignment (see CONFIG_HAVE_ALIGNED_STRUCT_PAGE)
> * for more.
> *
> * Use the supplied helper functions to endcode/decode the pointer and bits.
> */
> struct encoded_page;
>
> The struct is introduced by d57ab372568585 ("mm: introduce 'encoded' page
> pointers with embedded extra bits").
https://lore.kernel.org/all/CAHk-=wiyYSrBiOKJEV3phOBDT7EMgdXCnDUrp57E8HGNT4SFdA@xxxxxxxxxxxxxx/
I guess that nobody has "fixed" it yet.
--
~Randy
