On Tue, Dec 20, 2011 at 05:03:51PM -0500, Mouse wrote: > > From the annals of the POSIX wars: the rationale for posix_spawn() > > was to support systems without MMUs, where fork() is expensive, and > > vfork() impossible. > > I would quibble with calling vfork() `impossible'. Perhaps I'm missing > osmehting, but vfork() seems particularly well-suited to such a system > to me - the "borrow the VM" semantics strike me as exactly what you > want when context-switching is expensive. (Though of course the `V' of > `VM' is a bit of a misnomer in that circumstance.) > > In any case, even if I'm wrong, vfork isn't impossible, just, at worst, > ludicrously expensive. :-)
No, *v*fork is ~easy with no MMU; you just do nothing with the memory space at all. It's regular fork that's a problem. -- David A. Holland dholl...@netbsd.org
