The promise of large-scale persistent memory has forced a number of changes
in the kernel and has raised questions about whether the kernel's page
cache will be needed at all in the future.  In his linux.conf.au 2017 talk,
Matthew Wilcox asserted that not only do we still need the page cache, but
that its role should be increased.  First, though, there is the small
matter of correcting a mistake made by a certain Mr. Wilcox a couple of
years ago.