if (size <= 2*PAGE_SIZE)
mem->memory = kmalloc(size, GFP_KERNEL | __GFP_NORETRY);
if (mem->memory == NULL) {
mem->memory = vmalloc(size);
if (size <= 2*PAGE_SIZE)
mem->memory = kmalloc(size, GFP_KERNEL | __GFP_NORETRY);
if (mem->memory == NULL) {
mem->memory = vmalloc(size);