- * For pagecache intensive workloads, this function is the hottest
- * spot in the kernel (apart from copy_*_user functions).
- *
- * Appropriate locks must be held before calling this function.
- *
- * @nr_to_scan: The number of pages to look through on the list.
- * @src: The LRU list to pull pages off.
- * @dst: The temp list to put pages on to.
- * @scanned: The number of pages that were scanned.
- *
- * returns how many pages were moved onto *@dst.
- */
-static int isolate_lru_pages(int nr_to_scan, struct list_head *src,
- struct list_head *dst, int *scanned)
-{
- int nr_taken = 0;
- struct page *page;
- int scan = 0;
-
- while (scan++ < nr_to_scan && !list_empty(src)) {
- page = lru_to_page(src);
- prefetchw_prev_lru_page(page, src, flags);
-
- if (!TestClearPageLRU(page))
- BUG();
- list_del(&page->lru);
- if (get_page_testone(page)) {
- /*
- * It is being freed elsewhere
- */
- __put_page(page);
- SetPageLRU(page);
- list_add(&page->lru, src);
- continue;
- } else {
- list_add(&page->lru, dst);
- nr_taken++;
- }
- }
-
- *scanned = scan;
- return nr_taken;
-}
-
-/*