其实我今天也是第一次用，还没有很深入的了解这个工具的原理。
不过就下述而言，总体并发5，50，150是不错的，10，20比较差。
dba-test-A1-104:/usr/local # mysqlslap -a --concurrency=5,10,20,50,150 --number-of-queries 100000 --debug-info
Benchmark
        Average number of seconds to run all queries: 1053.520 seconds
        Minimum number of seconds to run all queries: 1053.520 seconds
        Maximum number of seconds to run all queries: 1053.520 seconds
        Number of clients running queries: 5
        Average number of queries per client: 20000

Benchmark
        Average number of seconds to run all queries: 1354.247 seconds
        Minimum number of seconds to run all queries: 1354.247 seconds
        Maximum number of seconds to run all queries: 1354.247 seconds
        Number of clients running queries: 10
        Average number of queries per client: 10000

Benchmark
        Average number of seconds to run all queries: 1221.182 seconds
        Minimum number of seconds to run all queries: 1221.182 seconds
        Maximum number of seconds to run all queries: 1221.182 seconds
        Number of clients running queries: 20
        Average number of queries per client: 5000

Benchmark
        Average number of seconds to run all queries: 1016.130 seconds
        Minimum number of seconds to run all queries: 1016.130 seconds
        Maximum number of seconds to run all queries: 1016.130 seconds
        Number of clients running queries: 50
        Average number of queries per client: 2000

Benchmark
        Average number of seconds to run all queries: 1012.727 seconds
        Minimum number of seconds to run all queries: 1012.727 seconds
        Maximum number of seconds to run all queries: 1012.727 seconds
        Number of clients running queries: 150
        Average number of queries per client: 666


User time 2473.98, System time 1242.23
Maximum resident set size 0, Integral resident set size 0
Non-physical pagefaults 156527636, Physical pagefaults 0, Swaps 0
Blocks in 0 out 0, Messages in 0 out 0, Signals 0
Voluntary context switches 106583066, Involuntary context switches 3655760

老外这篇文章挺好的
http://blogs.techrepublic.com.com/howdoi/?p=133