Kernel using high CPU
Kernel CPU can rise when the system is doing real low-level work: interrupt handling, scheduling, filesystem activity, or network processing.
Common symptoms
- Kernel/system frames dominate samples
- User-space apps do not explain load
- CPU correlates with storage or networking
Likely causes
- Heavy filesystem or network activity
- Driver or interrupt pressure
- Scheduling overhead
Evidence to look for
Kernel percentage rises in profiling
Disk or network events align with spikes
Run queue latency increases
What it usually means
Kernel CPU is not automatically bad, but it does change where you should look for the fix.
What to do next
- 1Check storage and networking first
- 2Look for interrupt-heavy devices or drivers
- 3Use profiling to separate kernel and user time
See what's causing your CPU
cpum.ai turns CPU, process, disk, and memory signals into plain-English explanations with evidence.
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