> + if (!page_order) {
> + area->nr_pages = alloc_pages_bulk_array_node(
> + gfp_mask, node, nr_small_pages, area->pages);
> + } else {
> + /*
> + * Careful, we allocate and map page_order pages, but tracking is done
> + * per PAGE_SIZE page so as to keep the vm_struct APIs independent of
Comments over 80 lines are completely unreadable, so please avoid them.
> + * the physical/mapped size.
> + */
> + while (area->nr_pages < nr_small_pages) {
> + struct page *page;
> + int i;
> +
> + /* Compound pages required for remap_vmalloc_page */
> + page = alloc_pages_node(node, gfp_mask | __GFP_COMP, page_order);
> + if (unlikely(!page))
> + break;
>
> + for (i = 0; i < (1U << page_order); i++)
> + area->pages[area->nr_pages + i] = page + i;
>
> + if (gfpflags_allow_blocking(gfp_mask))
> + cond_resched();
> +
> + area->nr_pages += 1U << page_order;
> + }
In fact splitting this whole high order allocation logic into a little
helper would massivel benefit the function by ordering it more logical
and reducing a level of indentation.
> + /*
> + * If not enough pages were obtained to accomplish an
> + * allocation request, free them via __vfree() if any.
> + */
> + if (area->nr_pages != nr_small_pages) {
> + warn_alloc(gfp_mask, NULL,
> + "vmalloc size %lu allocation failure: "
> + "page order %u allocation failed",
> + area->nr_pages * PAGE_SIZE, page_order);
> + goto fail;
> + }
>From reading __alloc_pages_bulk not allocating all pages is something
that cn happen fairly easily. Shouldn't we try to allocate the missing
pages manually and/ore retry here?
> +
> + if (vmap_pages_range(addr, addr + size, prot, area->pages, page_shift) < 0) {
Another pointlessly long line.
