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Date:   Fri, 20 Oct 2023 13:33:38 +0100
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Subject: Re: [PATCH v6 0/9] variable-order, large folios for anonymous memory
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To:     David Hildenbrand <david@redhat.com>,
        Andrew Morton <akpm@linux-foundation.org>,
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        Itaru Kitayama <itaru.kitayama@gmail.com>,
        "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>,
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References: <20230929114421.3761121-1-ryan.roberts@arm.com>
 <6d89fdc9-ef55-d44e-bf12-fafff318aef8@redhat.com>
From:   Ryan Roberts <ryan.roberts@arm.com>
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On 06/10/2023 21:06, David Hildenbrand wrote:
> On 29.09.23 13:44, Ryan Roberts wrote:
>> Hi All,
> 

[...]

>> NOTE: These changes should not be merged until the prerequisites are complete.
>> These are in progress and tracked at [7].
> 
> We should probably list them here, and classify which one we see as strict a
> requirement, which ones might be an optimization.
> 

Bringing back the discussion of prerequistes to this thread following the
discussion at the mm-alignment meeting on Wednesday.

Slides, updated following discussion to reflect all the agreed items that are
prerequisites and enhancements, are at [1].

I've taken a closer look at the situation with khugepaged, and can confirm that
it does correctly collapse anon small-sized THP into PMD-sized THP. I did notice
though, that one of the khugepaged selftests (collapse_max_ptes_none) fails when
small-sized THP is enabled+always. So I've fixed that test up and will add the
patch to the next version of my series.

So I believe the khugepaged prerequisite can be marked as done.

[1]
https://drive.google.com/file/d/1GnfYFpr7_c1kA41liRUW5YtCb8Cj18Ud/view?usp=sharing&resourcekey=0-U1Mj3-RhLD1JV6EThpyPyA

Thanks,
Ryan