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From: Lance Yang <ioworker0@gmail.com>
Date: Thu, 25 Apr 2024 12:19:45 +0800
Message-ID: <CAK1f24m2fR5EynwBN64Nuhcgctbd2RLXjLx7W_H+uywKLLO+cQ@mail.gmail.com>
Subject: Re: [PATCH v2 1/1] mm/vmscan: avoid split PMD-mapped THP during shrink_folio_list()
To: Andrew Morton <akpm@linux-foundation.org>
Cc: Matthew Wilcox <willy@infradead.org>, maskray@google.com, ziy@nvidia.com, 
	ryan.roberts@arm.com, david@redhat.com, 21cnbao@gmail.com, mhocko@suse.com, 
	fengwei.yin@intel.com, zokeefe@google.com, shy828301@gmail.com, 
	xiehuan09@gmail.com, wangkefeng.wang@huawei.com, songmuchun@bytedance.com, 
	peterx@redhat.com, minchan@kernel.org, linux-mm@kvack.org, 
	linux-kernel@vger.kernel.org
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On Thu, Apr 25, 2024 at 5:20=E2=80=AFAM Andrew Morton <akpm@linux-foundatio=
n.org> wrote:
>
> On Wed, 24 Apr 2024 23:46:59 +0800 Lance Yang <ioworker0@gmail.com> wrote=
:
>
> > On Wed, Apr 24, 2024 at 12:15=E2=80=AFPM Matthew Wilcox <willy@infradea=
d.org> 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 unneces=
sary.
> > > > If the THP is clean, its PMD is also clean, and there are no unexpe=
cted
> >
> > "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