The make tool can run jobs (commands) simultaneously instead to running them one by one. Works best on multiprocessor systems. To enable it, run:
$ make -j n
where n is the number of parallel jobs to execute. As per this analysis, the results are best when n = number of processors in the system.
This speeds up the compilation of large source code like that of the Linux kernel. As Bob has mentioned in his comment below, not all Makefiles are “job safe” and the jobs may be completed in any order. So be cautious when using the -j option.