Re: [PATCH net-next v9 10/13] mm: page_frag: introduce prepare/probe/commit API

[Alexander Duyck <alexander.duyck@gmail.com>]

On Sun, Jun 30, 2024 at 7:05 AM Yunsheng Lin <yunshenglin0825@gmail.com> wrote:
>
> On 6/30/2024 1:37 AM, Alexander Duyck wrote:
> > On Sat, Jun 29, 2024 at 4:15 AM Yunsheng Lin <linyunsheng@huawei.com> wrote:
>
> ...
>
> >>>
> >>> Why is this a macro instead of just being an inline? Are you trying to
> >>> avoid having to include a header due to the virt_to_page?
> >>
> >> Yes, you are right.

...

> > I am pretty sure you just need to add:
> > #include <asm/page.h>
>
> I am supposing you mean adding the above to page_frag_cache.h, right?
>
> It seems thing is more complicated for SPARSEMEM_VMEMMAP case, as it
> needs the declaration of 'vmemmap'(some arch defines it as a pointer
> variable while some arch defines it as a macro) and the definition of
> 'struct page' for '(vmemmap + (pfn))' operation.
>
> Adding below for 'vmemmap' and 'struct page' seems to have some compiler
> error caused by interdependence between linux/mm_types.h and asm/pgtable.h:
> #include <asm/pgtable.h>
> #include <linux/mm_types.h>
>

Maybe you should just include linux/mm.h as that should have all the
necessary includes to handle these cases. In any case though it
doesn't make any sense to have a define in one include that expects
the user to then figure out what other headers to include in order to
make the define work they should be included in the header itself to
avoid any sort of weird dependencies.