CPU high because kernel scheduling
When the scheduler is overloaded, it spends more time deciding what to run than actually running useful work.
Common symptoms
- CPU high but work completes slowly
- Latency is inconsistent
- Adding workers makes things worse
Likely causes
- Too many runnable tasks
- Noisy neighbor on shared hosts
- Background jobs overlapping with foreground work
Evidence to look for
Run queue latency elevated
Context switches high
CPU time spread broadly across many tasks
What it usually means
The machine is spending significant effort on scheduling overhead rather than productive computation.
What to do next
- 1Reduce total runnable task count
- 2Separate noisy workloads
- 3Lower background job overlap
See what's causing your CPU
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