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Pin down the CPU hog by PID (pidstat)

Performance · medium · live throwaway Linux box · 3 tiered hints

Using pidstat, find the PID of the process using the most CPU and write just that number to /home/player/answer.

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Fastest verified solves

• perf-e2e27s · ✦ no hints
• Tien472s · ✦ no hints

How it works

Press start and you get your own real, disposable Linux VM — in the browser terminal or over SSH. Work the task on a live system; tmpfs.tech grades your solution automatically against the actual machine state, then throws the box away. No install, free to try as a guest.

More Performance challenges

OS performance troubleshooting on a live box: hunt down CPU, memory, I/O and process problems with top, vmstat, iostat and pidstat.

• Count the zombie processesmedium
• Find the disk under load (iostat)medium
• Stop a CPU-pinning runawaymedium
• Stop a memory hogmedium
• Renice a greedy batch jobpro

See all Performance challenges →

FAQ

Is it free? Yes — play as a guest, no signup required to start.

Do I need to install anything? No. Everything runs in your browser, or connect over SSH if you prefer your own terminal.

How is it graded? Automatically and deterministically — your work is checked against the real state of the machine you worked on.