Le 22/10/2018 à 22:13, Dave Hansen a écrit :
Persistent memory is cool. But, currently, you have to rewrite
your applications to use it. Wouldn't it be cool if you could
just have it show up in your system like normal RAM and get to
it like a slow blob of memory? Well... have I got the patch
series for you!
This series adds a new "driver" to which pmem devices can be
attached. Once attached, the memory "owned" by the device is
hot-added to the kernel and managed like any other memory. On
systems with an HMAT (a new ACPI table), each socket (roughly)
will have a separate NUMA node for its persistent memory so
this newly-added memory can be selected by its unique NUMA
What happens on systems without an HMAT? Does this new memory get merged
into existing NUMA nodes?
Also, do you plan to have a way for applications to find out which NUMA
nodes are "real DRAM" while others are "pmem-backed"? (something like
new attribute in /sys/devices/system/node/nodeX/) Or should we use HMAT
performance attributes for this?