Performance Optimization

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Typical symptom Possible reason Solutions
sharply rising system CPU utilization. In addition, the page fault exception handler is do_huge_pmd_anonymous_page. This means that the current system doesn’t have 2 MB of contiguous physical memory and that triggers the direct memory compaction. The direct memory compaction is time-consuming, so it leads to high system CPU utilization THP-caused performance fluctuation.

The fragmentation index is associated with the /proc/sys/vm/extfrag_threshold parameter. The closer the number is to 1,000, the more the allocation failure is related to memory fragmentation.

To verify whether the performance fluctuation is related to memory fragmentation:

Disable THP (Transparent Huge Pages)

Reference