fn process_tree_io(pids: &[i32]) -> HashMap<i32, (u64, u64)>Expand description
Per-process cumulative disk I/O bytes from /proc/pid/io. Returns { pid -> (read_bytes, write_bytes) }. PIDs whose /proc/pid/io is unreadable (e.g. different UID without ptrace) are silently omitted – the delta for those PIDs will be 0.