On Mon, May 07, 2018 at 11:57:10AM -0700, Dan Williams wrote:
I think adding yet one more mm-zone is the wrong direction. Instead,
what we have been considering is a mechanism to allow a device-dax
instance to be given back to the kernel as a distinct numa node
managed by the VM. It seems it times to dust off those patches.
I was wondering how "safe" we think that ability is. NV-DIMM pages
(obviously) differ from normal pages by their non-volatility. Do we
want their contents from the previous boot to be observable? If not,
then we need the BIOS to clear them at boot-up, which means we would
want no kernel changes at all; rather the BIOS should just describe
those pages as if they were DRAM (after zeroing them).