Perf学习

重要的能解决的问题是这些：

perf_events is an event-oriented observability tool, which can help you solve advanced performance and troubleshooting functions. Questions that can be answered include:

• Why is the kernel on-CPU so much? What code-paths?
• Which code-paths are causing CPU level 2 cache misses?
• Are the CPUs stalled on memory I/O?
• Which code-paths are allocating memory, and how much?
• What is triggering TCP retransmits?
• Is a certain kernel function being called, and how often?
• What reasons are threads leaving the CPU?

原文地址：Linux perf Examples

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