Memory Used On global_status mariadb on mariadb at information_schema.global_status they have variable name  memory_used in bytes
this is actual memory use from mariadb ?
edit add example case
on my servers i have threads_running=10 and memory_used=2666 on MB so total 26 GB
but when run command free -mh is 89 gb
with configuration
...    
innodb_buffer_pool_size = 70G
innodb_buffer_pool_instances = 70
innodb_log_file_size = 8G
...
Local testing on toy test instance:
show global status like 'memory_used' 276360624
show session status like 'memory_used'; 69608
Looking the code the &quot;global memory used&quot; is the total of all the per connection memory allocations, but exclude actual global allocations like key_buffer, innodb_buffer_pool etc.