title: What is the unsigned int order in the function struct page* alloc_pages()
body: <p><code>struct page* alloc_pages(gfp_t gfp_mask, unsigned int order)</code> is the function used to allocate page in kernel. So this will allocate 2^order contiguous physical pages.
  So this means the pages will allocate in the manner of 1,2,4,8,16 and so on.
  What if only 3 pages are needed or 5 ,9 and so on.</p>