Linux
posts (5)
- CPU in Kubernetes from the kernel up8/12
Why 1 CPU does not mean one core
CPU time and CPU placement are two different mechanisms. A limit says how much you may consume; affinity and cpuset say where a task may execute.
- CPU in Kubernetes from the kernel up6/12
PSI: how Linux measures real CPU pressure
Utilisation says how much CPU a workload got. PSI measures the time it lost because it wanted to execute and had nothing to execute on.
- CPU in Kubernetes from the kernel up4/12
CPU Limits and throttling: what a CPU limit really does
A limit does not pin a container to a core. It gives it a CPU-time budget accounted per period, and once that runs out the kernel throttles it.
- CPU in Kubernetes from the kernel up2/12
cgroups and CPU: how Linux splits the processor between groups of processes
Group scheduling, cpu.weight and hierarchy - how the kernel divides CPU between groups of processes instead of individual tasks.
- CPU in Kubernetes from the kernel up1/12
How Linux really gives a process CPU
A process does not "have CPU". It is ready to run, and the scheduler decides when it actually gets processor time.