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2 min read
python profiling and optimize

profiling python

commandline profiling

1 python -m cProfile -s tottime your_program.py

优化

  • np random 比原生函数快四倍

  • 需要记住的延迟数据

    1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Latency Comparison Numbers L1 cache reference 0.5 ns Branch mispredict 5 ns L2 cache reference 7 ns 14x L1 cache Mutex lock/unlock 25 ns Main memory reference 100 ns 20x L2 cache, 200x L1 cache Compress 1K bytes with Zippy 3,000 ns 3 us Send 1K bytes over 1 Gbps network 10,000 ns 10 us Read 4K randomly from SSD* 150,000 ns 150 us ~1GB/sec SSD Read 1 MB sequentially from memory 250,000 ns 250 us Round trip within same datacenter 500,000 ns 500 us Read 1 MB sequentially from SSD* 1,000,000 ns 1,000 us 1 ms ~1GB/sec SSD, 4X memory Disk seek 10,000,000 ns 10,000 us 10 ms 20x datacenter roundtrip Read 1 MB sequentially from disk 20,000,000 ns 20,000 us 20 ms 80x memory, 20X SSD Send packet CA->Netherlands->CA 150,000,000 ns 150,000 us 150 ms

Refernce

  1. https://docs.python.org/3/library/profile.html

Contents

  1. 1. profiling python
  2. 2. 优化
  3. 3. Refernce

Python


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