numastat - Print statistics about NUMA memory allocation

numastat

numastat displays NUMA allocations statistics from the kernel memory allocator. Each process has NUMA policies that specifies on which node pages are allocated. See set_mempolicy(2) or numactl(8) on details of the available policies. The numastat counters keep track on what nodes memory is finally allocated.

The counters are separated for each node. Each count event is the allocation of a page of memory.

numa_hit is the number of allocations where an allocation was intended for that node and succeeded there.

numa_miss shows how often an allocation was intended for this node, but ended up on another node due to low memory.

numa_foreign is the number of allocations that were intended for another node, but ended up on this node. Each numa_foreign event has a numa_miss on another node.

interleave_hit is the number of interleave policy allocations that were intended for a specific node and succeeded there.

local_node is incremented when a process running on the node allocated memory on the same node.

other_node is incremented when a process running on another node allocated memory on that node.

numactl(8) set_mempolicy(2) numa(3)

numastat output is only available on NUMA systems.

numastat assumes the output terminal has a width of 80 characters and tries to format the output accordingly.

watch -n1 numastat

watch -n1 --differences=accumulative numastat

/sys/devices/system/node/node*/numastat

The output formatting on machines with a large number of nodes could be improved.