blog/content/2013/11/13/linux-howto-get-the-number-of-cpus.md

+++ title = "Linux: HOWTO get the number of CPUs" date = 2013-11-13T12:13:04+00:00 +++

$ getconf _NPROCESSORS_ONLN

returns the number of CPUs online.

Internally it is parsing /sys/devices/system/cpu/online, which can have the contents: 0-3,5,7-9.

Better let getconf do all the counting for you.

This is very useful, if you want to optimize the number of threads.