On Mon, Apr 27, 2020 at 04:47:42PM +0800, Shiyang Ruan wrote:
This patchset is a try to resolve the shared 'page cache'
In order to track multiple mappings and indexes on one page, I
introduced a dax-rmap rb-tree to manage the relationship. A dax entry
will be associated more than once if is shared. At the second time we
associate this entry, we create this rb-tree and store its root in
page->private(not used in fsdax). Insert (->mapping, ->index) when
dax_associate_entry() and delete it when dax_disassociate_entry().
Do we really want to track all of this on a per-page basis? I would
have thought a per-extent basis was more useful. Essentially, create
a new address_space for each shared extent. Per page just seems like
a huge overhead.