Memory allocation in kernel needs special care. Usually the plain malloc() is not enough, once interrupt and memory paging are in place. Since your piece of t

Memory allocation in kernel needs special care. Usually the plain malloc() is not enough, once interrupt and memory paging are in place. Since your piece of the kernel code can run in different interrupt level, you really need a pageable memory allocator and a non-pageable allocator. At a high level interrupt (like hardware interrupt), the memory paging service won't get a chance to run and accessing a pageable memory might crash the system. You want to allocate non-pageable, pinned down memory for your code that runs in high interrupt level. For low interrupt level code, it's fine to use pageable memory. That's why kernel mode development is a lot more difficult and fun.