On 16.06.23 00:00, Vishal Verma wrote:
For memory hotplug to consider MHP_MEMMAP_ON_MEMORY behavior, the
'memmap_on_memory' module parameter was a hard requirement.
In preparation for the dax/kmem driver to use memmap_on_memory
semantics, arrange for the module parameter check to be bypassed via the
appropriate mhp_flag.
Recall that the kmem driver could contribute huge amounts of hotplugged
memory originating from special purposes devices such as CXL memory
expanders. In some cases memmap_on_memory may be the /only/ way this new
memory can be hotplugged. Hence it makes sense for kmem to have a way to
force memmap_on_memory without depending on a module param, if all the
other conditions for it are met.
Just let the admin configure it. After all, an admin is involved in
configuring the dax/kmem device to begin with. If add_memory() fails you
could give a useful hint to the admin.
--
Cheers,
David / dhildenb
