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From: Miklos Szeredi <miklos@szeredi.hu>
Date: Wed, 11 Jan 2017 11:29:28 +0100
Message-ID: <CAJfpegv9EhT4Y3QjTZBHoMKSiVGtfmTGPhJp_rh3a7=rFCHu5A@mail.gmail.com>
Subject: [LSF/MM TOPIC] sharing pages between mappings
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I know there's work on this for xfs, but could this be done in generic mm code?

What are the obstacles?  page->mapping and page->index are the obvious ones.

If that's too difficult is it maybe enough to share mappings between
files while they are completely identical and clone the mapping when
necessary?

All COW filesystems would benefit, as well as layered ones: lots of
fuse fs, and in some cases overlayfs too.

Related:  what can DAX do in the presence of cloned block?

Thanks,
Miklos

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