[barrkel]

Windows uses page faults in the stack guard page to lazily commit stack pages. Compilers allocating large structures on the stack need to generate loops touching each allocated page in turn to guarantee the allocation. On Windows the lazy allocation can be done entirely in user code - it doesn't need to be an OS feature. I believe pthreads uses the same technique on Linux; very far from sure though.

Generational GC can use segfaults to detect writes to older generations and mark pages that need scanning for references to younger allocations. They can also act as a way of triggering a safe point without polluting the branch prediction cache: unmap a page when you want an interrupt, and periodically touch the page in code that needs interrupting (loops etc.). Virtual machines for languages like Java can and do use these techniques.