Editing Thread (computing) (section)

====History of threading models in Unix systems====
[[SunOS]] 4.x implemented ''[[light-weight process]]es'' or LWPs. [[NetBSD]] 2.x+, and [[DragonFly BSD]] implement LWPs as kernel threads (1:1 model). SunOS 5.2 through SunOS 5.8 as well as NetBSD 2 to NetBSD 4 implemented a two level model, multiplexing one or more user level threads on each kernel thread (M:N model). SunOS 5.9 and later, as well as NetBSD 5 eliminated user threads support, returning to a 1:1 model.<ref>{{Cite web |year=2002 |title=Multithreading in the Solaris Operating Environment |url=http://www.sun.com/software/whitepapers/solaris9/multithread.pdf |archive-url=https://web.archive.org/web/20090226174929/http://www.sun.com/software/whitepapers/solaris9/multithread.pdf |archive-date=February 26, 2009|url-status=dead}}</ref> FreeBSD 5 implemented M:N model. FreeBSD 6 supported both 1:1 and M:N, users could choose which one should be used with a given program using /etc/libmap.conf. Starting with FreeBSD 7, the 1:1 became the default. FreeBSD 8 no longer supports the M:N model.