Revert "mm: implement WasActive page flag (for improving cleancache)[…

…faux123] (Feedback welcome if there is a different/better way to do this without using a page flag!)"

This reverts commit 18ccba1.

include/linux/page-flags.h

@@ -54,9 +54,6 @@
  * PG_hwpoison indicates that a page got corrupted in hardware and contains
  * data with incorrect ECC bits that triggered a machine check. Accessing is
  * not safe since it may cause another machine check. Don't touch!
- *
- * PG_wasactive reflects that a page previously was promoted to active status.
- * Such pages should be considered higher priority for cleancache backends.
  */
 
 /*
@@ -110,9 +107,6 @@ enum pageflags {
 #endif
 #ifdef CONFIG_MEMORY_FAILURE
 	PG_hwpoison,		/* hardware poisoned page. Don't touch */
-#endif
-#ifdef CONFIG_CLEANCACHE
-	PG_was_active,
 #endif
 	__NR_PAGEFLAGS,
 
@@ -223,10 +217,6 @@ __PAGEFLAG(SlobFree, slob_free)
 __PAGEFLAG(SlubFrozen, slub_frozen)
 __PAGEFLAG(SlubDebug, slub_debug)
 
-#ifdef CONFIG_CLEANCACHE
-PAGEFLAG(WasActive, was_active)
-#endif
-
 /*
  * Private page markings that may be used by the filesystem that owns the page
  * for its own purposes.

mm/vmscan.c

@@ -524,10 +524,7 @@ void putback_lru_page(struct page *page)
 	int was_unevictable = PageUnevictable(page);
 
 	VM_BUG_ON(PageLRU(page));
-#ifdef CONFIG_CLEANCACHE
-	if (active)
-		SetPageWasActive(page);
-#endif
+
 redo:
 	ClearPageUnevictable(page);
 
@@ -1047,9 +1044,6 @@ static unsigned long clear_active_flags(struct list_head *page_list,
 		if (PageActive(page)) {
 			lru += LRU_ACTIVE;
 			ClearPageActive(page);
-#ifdef CONFIG_CLEANCACHE
-			SetPageWasActive(page);
-#endif
 			nr_active++;
 		}
 		count[lru]++;
@@ -1386,9 +1380,6 @@ static void shrink_active_list(unsigned long nr_pages, struct zone *zone,
 		}
 
 		ClearPageActive(page);	/* we are de-activating */
-#ifdef CONFIG_CLEANCACHE
-		SetPageWasActive(page);
-#endif
 		list_add(&page->lru, &l_inactive);
 	}