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Date:   Thu, 23 Nov 2023 16:18:12 +0000
From:   Matthew Wilcox <willy@infradead.org>
To:     David Hildenbrand <david@redhat.com>
Cc:     Ryan Roberts <ryan.roberts@arm.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        Yin Fengwei <fengwei.yin@intel.com>,
        Yu Zhao <yuzhao@google.com>,
        Catalin Marinas <catalin.marinas@arm.com>,
        Anshuman Khandual <anshuman.khandual@arm.com>,
        Yang Shi <shy828301@gmail.com>,
        "Huang, Ying" <ying.huang@intel.com>, Zi Yan <ziy@nvidia.com>,
        Luis Chamberlain <mcgrof@kernel.org>,
        Itaru Kitayama <itaru.kitayama@gmail.com>,
        "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>,
        John Hubbard <jhubbard@nvidia.com>,
        David Rientjes <rientjes@google.com>,
        Vlastimil Babka <vbabka@suse.cz>,
        Hugh Dickins <hughd@google.com>,
        Kefeng Wang <wangkefeng.wang@huawei.com>, linux-mm@kvack.org,
        linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org
Subject: Re: [RESEND PATCH v7 00/10] Small-sized THP for anonymous memory
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 <7f76ee6c-f0e6-443b-bcff-3637895dec66@redhat.com>
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On Thu, Nov 23, 2023 at 05:05:37PM +0100, David Hildenbrand wrote:
> On 23.11.23 16:59, Matthew Wilcox wrote:
> > On Wed, Nov 22, 2023 at 04:29:40PM +0000, Ryan Roberts wrote:
> > > Note: I'm resending this at Andrew's suggestion due to having originally sent
> > > it during LPC. I'm hoping its in a position where the feedback is minor enough
> > > that I can rework in time for v6.8, but so far haven't had any.
> > > 
> > > Hi All,
> > > 
> > > This is v7 of a series to implement small-sized THP for anonymous memory
> > > (previously called "large anonymous folios"). The objective of this is to
> > 
> > I'm still against small-sized THP.  We've now got people asking whether
> > the THP counters should be updated when dealing with large folios that
> > are smaller than PMD sized.  It's sowing confusion, and we should go
> > back to large anon folios as a name.
> > 
> 
> I disagree.
> 
> https://lore.kernel.org/all/65dbdf2a-9281-a3c3-b7e3-a79c5b60b357@redhat.com/

And yet:
https://lore.kernel.org/linux-mm/20231106193315.GB3661273@cmpxchg.org/

"This is a small THP so we don't account it as a THP, we only account
normal THPs as THPs" is a bizarre position to take.

Not to mention that saying a foo is a small huge baz is just bizarre.
Am I a small giant?  Or just a large human?