-/**
- * swapin_readahead - swap in pages in hope we need them soon
- * @entry: swap entry of this memory
- * @addr: address to start
- * @vma: user vma this addresses belong to
- *
- * Primitive swap readahead code. We simply read an aligned block of
- * (1 << page_cluster) entries in the swap area. This method is chosen
- * because it doesn't cost us any seek time. We also make sure to queue
- * the 'original' request together with the readahead ones...
- *
- * This has been extended to use the NUMA policies from the mm triggering
- * the readahead.
- *
- * Caller must hold down_read on the vma->vm_mm if vma is not NULL.
- */
-void swapin_readahead(swp_entry_t entry, unsigned long addr,struct vm_area_struct *vma)
-{
-#ifdef CONFIG_NUMA
- struct vm_area_struct *next_vma = vma ? vma->vm_next : NULL;
-#endif
- int i, num;
- struct page *new_page;
- unsigned long offset;
-
- /*
- * Get the number of handles we should do readahead io to.
- */
- num = valid_swaphandles(entry, &offset);
- for (i = 0; i < num; offset++, i++) {
- /* Ok, do the async read-ahead now */
- new_page = read_swap_cache_async(swp_entry(swp_type(entry),
- offset), vma, addr);
- if (!new_page)
- break;
- page_cache_release(new_page);
-#ifdef CONFIG_NUMA
- /*
- * Find the next applicable VMA for the NUMA policy.
- */
- addr += PAGE_SIZE;
- if (addr == 0)
- vma = NULL;
- if (vma) {
- if (addr >= vma->vm_end) {
- vma = next_vma;
- next_vma = vma ? vma->vm_next : NULL;
- }
- if (vma && addr < vma->vm_start)
- vma = NULL;
- } else {
- if (next_vma && addr >= next_vma->vm_start) {
- vma = next_vma;
- next_vma = vma->vm_next;
- }
- }
-#endif
- }
- lru_add_drain(); /* Push any new pages onto the LRU now */
-}
-