On Wed, 2022-05-11 at 23:22 -0700, Wei Xu wrote: > Sysfs Interfaces > ================ > > * /sys/devices/system/memtier/memtierN/nodelist > > where N = 0, 1, 2 (the kernel supports only 3 tiers for now). > > Format: node_list > > Read-only. When read, list the memory nodes in the specified tier. > > Tier 0 is the highest tier, while tier 2 is the lowest tier. > > The absolute value of a tier id number has no specific meaning. > What matters is the relative order of the tier id numbers. > > When a memory tier has no nodes, the kernel can hide its memtier > sysfs files. > > * /sys/devices/system/node/nodeN/memtier > > where N = 0, 1, ... > > Format: int or empty > > When read, list the memory tier that the node belongs to. Its value > is empty for a CPU-only NUMA node. > > When written, the kernel moves the node into the specified memory > tier if the move is allowed. The tier assignment of all other nodes > are not affected. > > Initially, we can make this interface read-only. It seems that "/sys/devices/system/node/nodeN/memtier" has all information we needed. Do we really need "/sys/devices/system/memtier/memtierN/nodelist"? That can be gotten via a simple shell command line, $ grep . /sys/devices/system/node/nodeN/memtier | sort -n -k 2 -t ':' Best Regards, Huang, Ying
