On 1/17/19 11:47 PM, Yanmin Zhang wrote:

a chance for kernel to allocate PMEM as DMA buffer.
Some super speed devices like 10Giga NIC, USB (SSIC connecting modem),
might not work well if DMA buffer is in PMEM as it's slower than DRAM.

Should your patchset consider it?

No, I don't think so.

They can DMA to persistent memory whether this patch set exists or not.
 So, if the hardware falls over, that's a separate problem.

If an app wants memory that performs in a particular way, then I would
suggest those app find the NUMA nodes on the system that match their
needs with these patches:

http://lkml.kernel.org/r/20190116175804.30196-1-keith.busch@intel.com

and use the existing NUMA APIs to select that memory.