Thanks for the hint Brian. I can easily create another thread that can pause/resume the other worker threads, but I have no idea how this thread could constantly and non-intrusively monitor system load. -----Original Message----- From: boost-users-bounces@lists.boost.org [mailto:boost-users-bounces@lists.boost.org] On Behalf Of Brian Allison Sent: Saturday, 19 November 2005 2:21 a.m. To: boost-users@lists.boost.org Subject: Re: [Boost-users] Boost::thread scheduling under HPUX AFAIK Pete, there are no POSIX hooks for doing this by way of having the kernel control the sleeping status of a program wrt the load factor. The typical approach for this problem involves having a control thread whose purpose is to control the work speed of the threads. This usually involves a programmatic solution - the nice values are only suggestions to the scheduling routine IIRC.