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Date:   Tue, 20 Nov 2018 05:12:47 -0800
From:   Matthew Wilcox <willy@infradead.org>
To:     Hugh Dickins <hughd@google.com>
Cc:     Yu Zhao <yuzhao@google.com>,
        Andrew Morton <akpm@linux-foundation.org>, linux-mm@kvack.org,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2] mm: fix swap offset when replacing shmem page
Message-ID: <20181120131247.GA3065@bombadil.infradead.org>
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On Mon, Nov 19, 2018 at 09:07:27PM -0800, Hugh Dickins wrote:
> I don't much like my original use of the name "swap_index", when it was
> not the index in a swapfile (though it was the index in the radix tree);
> but it will become a correct name with your patch.
> 
> Though Matthew Wilcox seems to want us to avoid saying "radix tree"...

Naming is hard ... but the Linux radix tree looks almost nothing like
a classic computer science radix tree.  If you try to reconcile our
implementation with the wikipedia article on radix trees, you'll get
very confused.

A lot of places where we were saying 'radix tree' in comments should
really have said 'page cache'.  So is this a swap cache index?  I'm
not really familiar enough with the swapping code to say.