TinyVMem is a public domain implementation of the VMem resource allocator first described in the paper “Magazines and Vmem: Extending the Slab Allocator to Many CPUs and Arbitrary Resources”

• VMem, despite its name, is not limited to allocation of virtual address space; it can deal with any sort of interval scale (for example, PIDs).
• Support for multiple allocation strategies such as best-fit and instant fit (constant time). Next-fit support is planned.
• Reduced fragmentation.
• Allows importing spans from other arenas.

TinyVMem is written in portable ANSI C therefore porting to a new platform should be easy enough. If you’re running on a freestanding environment, you need to define the __KERNEL__ macro and the following functions/macros:

/* Allocates 'n' pages */
void *vmem_alloc_pages(size_t n);

/* Locks a global lock (defined by the user) */
void vmem_lock(void);

/* Locks a global lock (defined by the user) */
void vmem_unlock(void);

/* From libc's string.h */
char *strcpy(char *restrict dst, const char *restrict src);

/* Assertion */
#define ASSERT(...) assert

/* Printf-like function, can be ignored if you're not going to call vmem_dump() */
#define vmem_printf(...) printf

You also need to have a complete implementation of sys/queue.h available. If not, I suggest you use netbsd’s.

• Implement support for next-fit allocation
• Implement support for VM_NOSLEEP and VM_SLEEP