Memory allocation in the kernel

alloc_free.c

static void *rvmalloc(unsigned long size)
{
	void *mem;
	unsigned long adr;

	size = PAGE_ALIGN(size);
	mem = vzalloc(size); //syscalls_trace_buffer;//vmalloc(size);
#	if (SHM_RESERVE_PAGES > 0)
	if (mem) {
		// memset(mem, 0, size);  vzalloc() will zero the memory
		adr = (unsigned long) mem;
		while (size > 0) {
			SetPageReserved(vmalloc_to_page((void *)adr));
			adr += PAGE_SIZE;
			size -= PAGE_SIZE;
		}
	}
#	endif
	return mem;
}

static void rvfree(void * mem, unsigned long size)
{
	unsigned long adr;

	if (mem) {
#	if (SHM_RESERVE_PAGES > 0)
		adr = (unsigned long) mem;
		while ((long) size > 0) {
			ClearPageReserved(vmalloc_to_page((void *)adr));
			adr += PAGE_SIZE;
			size -= PAGE_SIZE;
		}
#endif
		vfree(mem);
	}
}