补充知识：
　　查看CPU核数的方法
　　查看物理cpu个数
　　grep "physical id" /proc/cpuinfo | sort -u | wc -l
　　查看核心数量
　　grep "core id" /proc/cpuinfo | sort -u | wc -l
　　查看线程数量
　　grep "processor" /proc/cpuinfo | sort -u | wc -l
　　在sysbench的测试中，--num-threads取值为"线程数量"即可，再大的值没有什么意义，对测试结果也没有什么影响。
　　3.2 线程(thread)测试
　　测试线程调度器的性能。对于高负载情况下测试线程调度器的行为非常有用。
　　sysbench --test=threads --num-threads=64 run
　　下面是输出结果：

 

Number of threads: 64
Doing thread subsystem performance test
Thread yields per test: 1000 Locks used: 8
Threads started!
Done.
Test execution summary:
total time: 4.5845s
total number of events: 10000
total time taken by event execution: 291.9995
per-request statistics:
min: 0.76ms
avg: 29.20ms
max: 152.71ms
approx. 95 percentile: 71.11ms
Threads fairness:
events (avg/stddev): 156.2500/5.81
execution time (avg/stddev): 4.5625/0.02

　　说实话，我也不怎么会分析这个测试结果，网上搜了半天也没有搜到，几乎所有的资料都是简单的罗列出测试结果， 也不告诉我们应该怎么分析，实在是太不照顾新手了。 我自己是通过（total time:）判断线程调度的性能的，下面是我在服务器上运行这个测试的输出：

 

Number of threads: 64
Doing thread subsystem performance test
Thread yields per test: 1000 Locks used: 8
Threads started!
Done.
Test execution summary:
total time: 2.4829s
total number of events: 10000
total time taken by event execution: 157.3468
per-request statistics:
min: 0.21ms
avg: 15.73ms
max: 166.69ms
approx. 95 percentile: 119.14ms
Threads fairness:
events (avg/stddev): 156.2500/22.25
execution time (avg/stddev): 2.4585/0.02

　　可以看到total time 比在我自己电脑上少了一半，服务器的线程调度肯定比普通电脑快多了。

　　3.3 互斥锁(mutex)
　　测试互斥锁的性能，方式是模拟所有线程在同一时刻并发运行，并都短暂请求互斥锁。
　　sysbench --test=mutex --num-threads=16 --mutex-num=2048
　　--mutex-locks=1000000 --mutex-loops=5000 run
　　输出结果如下：

 

Number of threads: 16
Doing mutex performance test
Threads started!
Done.
Test execution summary:
total time: 3.6123s
total number of events: 16
total time taken by event execution: 57.6636
per-request statistics:
min: 3580.79ms
avg: 3603.98ms
max: 3610.94ms
approx. 95 percentile: 10000000.00ms
Threads fairness:
events (avg/stddev): 1.0000/0.00
execution time (avg/stddev): 3.6040/0.01