现在机器的cpu越来越复杂，一个cpu，经常是几个内核，4，6，8都不是什么稀罕的事情。

　　当年我公司购买一台8cpu的AMD服务器，双核，当时看到cpu很壮观，16个cpu。

　　现在一台普通的2U的服务器，都可能看到这种场景。

　　http://planet.admon.org/howto/about-cpu-the-logical-and-physical-cores/

　　There are some commands here to help identify these type of information quickly on a running Linux:

　　Total amount of processors including the logical ones:

　　# cat /proc/cpuinfo | grep “processor“| wc -l

　　Total amount of CPU package:

　　# cat /proc/cpuinfo | grep “physical id“ | sort | uniq | wc -l

　　How many cores for each CPU. (Here we should call CPU as physical package as we mentioned above):

　　# cat /proc/cpuinfo | grep “cpu cores“ | wc -l

　　For each physical CPU, the amount of Logical CPU (the logical CPU can be physical cores, soft cores like threaded, or both).

　　# cat /proc/cpuinfo | grep “siblings“