alloc_pages
alloc_pages(dpcpu, DPCPU_SIZE / PAGE_SIZE);
alloc_pages(msgbufpv, round_page(msgbufsize) / PAGE_SIZE);
page = alloc_pages(gfp | __GFP_COMP, order);
pages = alloc_pages(gfp, flsl(howmany(fragsz, PAGE_SIZE) - 1));
page = alloc_pages(gfp_mask, order);
page = alloc_pages(gfp_mask | __GFP_ZERO, order);