Is hyper-threading enabled on a Linux system ?

When you need to know whether hyper-threading is enabled without the luxury to reboot the system,
you can simply look at the output of /proc/cpuinfo and compare the siblings with the cpu cores fields.

The most common answer was to check the values of 'cpu cores' and 'siblings' in /proc/cpuinfo.
When Hyper-Threading is enabled, those values should be different for each logical processor:


# egrep 'siblings|cpu cores' /proc/cpuinfo | head -2

siblings : 12
cpu cores : 6



As you can see on my test System HT is enabled.