40 lines
1.2 KiB
Markdown
40 lines
1.2 KiB
Markdown
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# perf 功能强大的linux性能分析工具
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`perf [command] [options] [arguments]`
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子命令 额外选项 要分析的程序或命令
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## 性能概览
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`perf stat <command>`
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> 性能计数器
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```
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0.60 msec task-clock # 0.589 CPUs utilized cpu利用率
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0 context-switches # 0.000 /sec 上下文切换次数
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0 cpu-migrations # 0.000 /sec cpu切换
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68 page-faults # 113.661 K/sec 页错误次数
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1,772,372 cycles # 2.963 GHz 时钟周期
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1,247,336 instructions # 0.70 insn per cycle 指令数量
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229,972 branches # 384.396 M/sec 分支数量
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8,262 branch-misses # 3.59% of all branches 未命中分支
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0.001016124 seconds time elapsed 总用时
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0.000000000 seconds user
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0.001106000 seconds sys
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```
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## 记录性能数据
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`perf record -g -o output.data <command>`
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+ -o 指定输出文件
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+ -g 启用调用图
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`sudo perf record -a -g -o system.data`
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+ -a 采集系统级数据
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## 分析性能数据
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`perf report -i output.data`
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+ -i 指定输入文件
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## 实时性能监控
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`sudo perf top`
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