linux-kernel - Re: [PATCH RFC 6/6] mm: madvise: don't split mTHP for MADV

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Message-ID: <CAGsJ_4xFgcf8+ZqKUqQ3gQt63JXtn-VifAk5mTA6dopYvNqGqA@mail.gmail.com>
Date: Wed, 28 Feb 2024 07:57:00 +1300
From: Barry Song <21cnbao@...il.com>
To: Ryan Roberts <ryan.roberts@....com>
Cc: akpm@...ux-foundation.org, david@...hat.com, linux-mm@...ck.org, 
	linux-kernel@...r.kernel.org, mhocko@...e.com, shy828301@...il.com, 
	wangkefeng.wang@...wei.com, willy@...radead.org, xiang@...nel.org, 
	ying.huang@...el.com, yuzhao@...gle.com, surenb@...gle.com, 
	steven.price@....com, Chuanhua Han <hanchuanhua@...o.com>, 
	Barry Song <v-songbaohua@...o.com>
Subject: Re: [PATCH RFC 6/6] mm: madvise: don't split mTHP for MADV_PAGEOUT

On Wed, Feb 28, 2024 at 3:40 AM Ryan Roberts <ryan.roberts@....com> wrote:
>
> On 18/01/2024 11:10, Barry Song wrote:
> > From: Chuanhua Han <hanchuanhua@...o.com>
> >
> > MADV_PAGEOUT and MADV_FREE are common cases in Android. Ryan's patchset has
> > supported swapping large folios out as a whole for vmscan case. This patch
> > extends the feature to madvise.
> >
> > If madvised range covers the whole large folio, we don't split it. Otherwise,
> > we still need to split it.
> >
> > This patch doesn't depend on ARM64's CONT-PTE, alternatively, it defines one
> > helper named pte_range_cont_mapped() to check if all PTEs are contiguously
> > mapped to a large folio.
>
> I'm going to rework this patch and integrate it into my series if that's ok with
> you?

This is perfect. Please integrate it into your swap-out series which is the
perfect place for this MADV_PAGEOUT.

Thanks
Barry