On Thu, Dec 23, 2021 at 02:18:40PM +0000, Matthew Wilcox wrote:

quoted

I think these casts need documentation, both here and at the
struct folio_batch and struct pagevec definitions.

Alternatively I wonder if a union in stuct pagevec so that it can store
folios or pages might be the better option.

I tried that way first, but then the caller & callee need to agree
whether they're storing folios or pages in the pagevec.  And that's kind
of why we have types.

pagevec_remove_exceptionals() goes away by the end of this series.
pagevec_release() will take longer to remove.  What documentation
do you want to see?

Mostly comments at the pagevec and folio_batch definitions that they
need to match because of these two functions, and then maybe a
backreference from the casts to the definitions.