> Which it is. Fork shares no memory regions; vfork/clone share all > memory regions. AFAIK there is no share-heap-but-not-stack option in > Linux. Thats a design decision. At the point you don't have identical mappings for both threads you need two sets of page tables and you take all the performance hits that go with changing current tables on a schedule. Its a lot cheaper to use a different %esp for each thread
