The EMERGE_DEFAULT_OPTS variable entries are appended to the emerge command line. It is often used to allow for concurrent emerge operations through the
--jobs N and
--load-average X.Y options, which tell Portage how many parallel package builds can be used and up to what system load (load average) the parallelism can be used.
For example, to run up to three jobs in parallel:
For more information, see the EMERGE_DEFAULT_OPTS article.