Flowdock
method

nprocessors

Importance_2
v2_5_5 - Show latest stable - 0 notes - Class: Etc
nprocessors() public

Returns the number of online processors.

The result is intended as the number of processes to use all available processors.

This method is implemented using:

  • sched_getaffinity(): Linux

  • sysconf(_SC_NPROCESSORS_ONLN): GNU/Linux, NetBSD, FreeBSD, OpenBSD, DragonFly BSD, OpenIndiana, Mac OS X, AIX

Example:

require 'etc'
p Etc.nprocessors #=> 4

The result might be smaller number than physical cpus especially when ruby process is bound to specific cpus. This is intended for getting better parallel processing.

Example: (Linux)

linux$ taskset 0x3 ./ruby -retc -e "p Etc.nprocessors"  #=> 2
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