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Date:   Thu, 9 Sep 2021 12:17:00 -0700
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Subject: Re: [GIT PULL] Memory folios for v5.15
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To:     Vlastimil Babka <vbabka@suse.cz>,
        Christoph Hellwig <hch@infradead.org>,
        Matthew Wilcox <willy@infradead.org>
Cc:     Linus Torvalds <torvalds@linux-foundation.org>, linux-mm@kvack.org,
        linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org,
        Andrew Morton <akpm@linux-foundation.org>,
        Johannes Weiner <hannes@cmpxchg.org>
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From:   John Hubbard <jhubbard@nvidia.com>
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On 9/9/21 06:56, Vlastimil Babka wrote:
> On 9/9/21 14:43, Christoph Hellwig wrote:
>> So what is the result here?  Not having folios (with that or another
>> name) is really going to set back making progress on sane support for
>> huge pages.  Both in the pagecache but also for other places like direct
>> I/O.
> 
> Yeah, the silence doesn't seem actionable. If naming is the issue, I believe
> Matthew had also a branch where it was renamed to pageset. If it's the
> unclear future evolution wrt supporting subpages of large pages, should we
> just do nothing until somebody turns that hypothetical future into code and
> we see whether it works or not?
> 

When I saw Matthew's proposal to rename folio --> pageset, my reaction was,
"OK, this is a huge win!". Because:

* The new name addressed Linus' concerns about naming, which unblocks it
   there, and

* The new name seems to meet all of the criteria of the "folio" name,
   including even grep-ability, after a couple of tiny page_set and pageset
   cases are renamed--AND it also meets Linus' criteria for self-describing
   names.

So I didn't want to add noise to that thread, but now that there is still
some doubt about this, I'll pop up and suggest: do the huge
's/folio/pageset/g', and of course the associated renaming of the conflicting
existing pageset and page_set cases, and then maybe it goes in.


thanks,
-- 
John Hubbard
NVIDIA