net_cls in the time of cgroup v2

Do you ever wonder how to apply specific networking rules to a chosen program, e.g. a browser? Network rules based on PID (process ID) were dropped in 2005 for good reasons. Let’s not bring up entire containers for a moment (where you can define separate configuration in network_namespaces(7)) but take only one part of them, […]

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What is a kernel thread?

The title suggests there exists one such concept as a kernel thread. The reality is much more complex than mere kernel threads and the rest. The practical need of differentiation popped up when systemd service manager needed to terminate all processes except for kernel threads. Ideally, the kernel threads would stay in the background doing […]

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