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Date:   Mon, 15 Mar 2021 19:09:04 +0000
From:   Christoph Hellwig <hch@infradead.org>
To:     Michal Hocko <mhocko@suse.com>
Cc:     "Kirill A. Shutemov" <kirill@shutemov.name>,
        Hugh Dickins <hughd@google.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        "Matthew Wilcox (Oracle)" <willy@infradead.org>,
        linux-mm@kvack.org, linux-kernel@vger.kernel.org,
        linux-fsdevel@vger.kernel.org
Subject: Re: [PATCH v4 00/25] Page folios
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On Mon, Mar 15, 2021 at 01:38:04PM +0100, Michal Hocko wrote:
> I tend to agree here as well. The level compoud_head has spread out
> silently is just too large. There are people coming up with all sorts of
> optimizations to workaround that, and they are quite right that this is
> somehing worth doing, but last attempts I have seen were very focused on
> specific page flags handling which is imho worse wrt maintainability
> than a higher level and type safe abstraction. I find it quite nice that
> this doesn't really have to be a flag day conversion but it can be done
> incrementally.
> 
> I didn't get review the series yet and I cannot really promise anything
> but from what I understand the conversion should be pretty
> straightforward, albeit noisy.
> 
> One thing that was really strange to me when seeing the concept for the
> first time was the choice of naming (no I do not want to start any
> bikeshedding) because it hasn't really resonated with the udnerlying
> concept. Maybe just me as a non native speaker... page_head would have
> been so much more straightforward but not something I really care about.

That pretty much summarizes my opinion as well.  I'll need to find some
time to review the series as well.