On Mon, 21 Nov 2022, Kirill A. Shutemov wrote:
> On Fri, Nov 18, 2022 at 01:12:03AM -0800, Hugh Dickins wrote:
>
> Acked-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
Thanks a lot for all these, Kirill.
>
> Few minor nitpicks below.
>
...
> > static inline void page_dup_file_rmap(struct page *page, bool compound)
> > {
> > - if (PageCompound(page))
> > - page_dup_compound_rmap(page, compound);
> > - else
> > + if (likely(!compound /* page is mapped by PTE */))
>
> I'm not a fan of this kind of comments.
>
> Maybe move above the line (here and below)?
Okay, done throughout. I wouldn't have added those comments, but Linus
had another "simmering hatred", of the "compound" arguments: he found
them very confusing.
The real fix is to rename them, probably to pmd_mapped; or better, pass
down an int nr_pages as he suggested; but I'm wary of the HPAGE_NR_PAGES
build bug, and it wants to be propagated through various other files
(headers and mlock.c, maybe more) - not a cleanup to get into now.
>
> > atomic_inc(&page->_mapcount);
> > + else
> > + page_dup_compound_rmap(page);
> > }
...
> > @@ -1176,20 +1157,16 @@ void page_dup_compound_rmap(struct page *page, bool compound)
> > * Note that hugetlb does not call page_add_file_rmap():
> > * here is where hugetlb shared page mapcount is raised.
> > */
> > - if (PageHuge(page)) {
> > - atomic_inc(compound_mapcount_ptr(page));
> > - return;
> > - }
> > + if (PageHuge(head)) {
> > + atomic_inc(compound_mapcount_ptr(head));
> >
>
> Remove the newline?
It was intentional there, I thought it was easier to read that way;
but since this gets reverted in the next patch, I've no reason to
fight over it - removed.
Hugh
