cgroups (Control Groups)
Linux kernel mechanism metering and limiting hardware resource allocations (CPU, memory, disk I/O) for process groups.
Mechanism & Definition
A Linux kernel subsystem (v1/v2) that allocates, meters, and limits hardware resources across arbitrary process hierarchies. Container runtimes configure cgroup controllers (`memory.max`, `cpu.max`, `io.weight`) to prevent noisy-neighbor workloads from exhausting host compute and memory.