On Mon, Oct 28, 2019 at 01:28:09PM +0300, Konstantin Khlebnikov wrote: > + if (dax_mapping(mapping)) > + pages = READ_ONCE(mapping->nrexceptional); > + else > + pages = READ_ONCE(mapping->nrpages); I'm not sure this is the right calculation for DAX files. We haven't allocated any memory for DAX; we're just accessing storage directly. The entries in the page caache are just translation from file offset to physical address.