taskset tips — authorized cpu-affinity literacy

Snapshot

Tip checklist (authorized only)

1. Confirm you may run taskset on the lab host (syllabus box you own or were given access to).
2. Prefer documenting who / why / ticket before any affinity change — never poke production without change control.
3. Record short factual notes; quote short Evidence (CPU mask / list labels — never secrets from target processes).
4. Optional: scheduler peer → chrt-tips / nice-tips.
5. Optional: NUMA peer → numactl-tips.
6. Prefer disposable lab PIDs for taskset drills; quote non-secret labels afterward as Evidence.
7. Prefer read-only -p / -c inspect modes for most Evidence binders unless the syllabus asks for write drills.
8. Stop at literacy — no attack or unauthorized interference cookbooks.

Allowed framing

• Classroom labs reviewing taskset on authorized disposable processes (taskset -p / -c read-backs).
• Binding short factual notes as Evidence (CPU mask labels — no secrets).
• Documenting expected vs observed CPU-affinity literacy for authorized inventory notes.
• Comparing taskset ↔ peer tip pages under one binder.
• Testing affinity writes only when the syllabus authorizes that drill on lab resources.

Scope we will not cover

• No crack/pirate/keygen via taskset.
• No intentional unauthorized interference with foreign production schedulers.
• No secret-theft or credential harvesting via process inspect on hosts you do not own.
• No cookbooks that weaken cpuset/cgroup controls on foreign hosts without authorization.

Beginner path (authorized only)

1. Obtain one syllabus-approved disposable lab host with a usable taskset toolchain.
2. Prefer a throwaway lab process before any write drill.
3. With authorization, run a syllabus-approved taskset -p <lab-pid>; quote CPU mask labels as Evidence.
4. Optional: peer tip pages above when the syllabus asks.
5. Stop at literacy — no attack or unauthorized interference cookbooks.

Practical notes for authorized labs

• taskset reads/writes CPU affinity masks — keep Evidence labels distinct from scheduler policy chrt-tips.
• Pair with numactl-tips only for syllabus-approved NUMA literacy on lab hosts.
• Target process command lines may embed secrets — never paste them into notes or git.
• Prefer documenting CPU lists/masks the syllabus authorized without dumping full /proc secret context.
• Never commit taskset dumps with secrets to git — even for labs.

FAQ

Sources