> This series adds a new "driver" to which pmem devices
> attached. Once attached, the memory "owned" by the device is
> hot-added to the kernel and managed like any other memory. On
Would this memory be considered volatile (with the driver initializing
it to zeros), or persistent (contents are presented unchanged,
applications may guarantee persistence by using cache flush
instructions, fence instructions, and writing to flush hint addresses
per the persistent memory programming model)?
> I expect udev can automate this by setting up a rule to watch
> device-dax instances by UUID and call a script to do the detach /
> reattach dance.
Where would that rule be stored? Storing it on another device
is problematic. If that rule is lost, it could confuse other
drivers trying to grab device DAX devices for use as persistent
Well, we do lots of things like stable device naming from udev scripts.
We depend on them not being lost. At least this "fails safe" so we'll
default to persistence instead of defaulting to "eat your data".