Re: [PATCH v2 1/1] mm/vmscan: avoid split PMD-mapped THP during shrink_folio_list()

[Lance Yang]

On Thu, Apr 25, 2024 at 5:20 AM Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> wrote:
>
> On Wed, 24 Apr 2024 23:46:59 +0800 Lance Yang <ioworker0@xxxxxxxxx> wrote:
>
> > On Wed, Apr 24, 2024 at 12:15 PM Matthew Wilcox <willy@xxxxxxxxxxxxx> wrote:
> > >
> > > On Mon, Apr 22, 2024 at 01:52:13PM +0800, Lance Yang wrote:
> > > > When the user no longer requires the pages, they would use
> > > > madvise(MADV_FREE) to mark the pages as lazy free. IMO, they would not
> > > > typically rewrite to the given range.
> > > >
> > > > At present, PMD-mapped THPs that are marked as lazyfree during
> > > > shrink_folio_list() are unconditionally split, which may be unnecessary.
> > > > If the THP is clean, its PMD is also clean, and there are no unexpected
> >
> > "If the THP is clean, its PMD is also clean" can be confusing - sorry. It should
> > be modified to "If the THP and its PMD are both marked as clean".
>
> I made that changelog edit.

Thanks for updating, Andrew!
Lance