Number of Processors

If your coworker or colleague ever asked you to find out how many processor does the linux server have, then...

Simply issue the following command as root

# cat /proc/cpuinfo | grep processor

Everything in linux is files. This command simply retrieves the number of processors that linux detected from /proc/cpuinfo and displays it. Usually, the processor number comes at the first set of line from issuing the command.

Here’s what the command returned for me:
~~~~~~~~~~~~~~~~~~~~~~~~
processor : 0
~~~~~~~~~~~~~~~~~~~~~~~~

which means You have 1 processor with a processor ID number 0. Processor counting starts with 0.
So if you have a PC with core duo, you will probably have 2 lines that says 0 and 1.That is 2 processors.


You can run the command below and you will see number of physical processors in the server:

[server][root][~]# grep “^physical id” /proc/cpuinfo | awk ‘{print $NF}’ | uniq | wc -l
1

Now lets determine how many cores we have:

[server][root][~]# cat /proc/cpuinfo | grep processor | wc -l
4