swap: discard while swapping only if SWAP_FLAG_DISCARD_PAGES

[deliverable/linux.git] / include / linux / swap.h

diff --git a/include/linux/swap.h b/include/linux/swap.h
index 1701ce4be746502e89b6dfb417547c1ba805d466..d95cde5e257d9d23c71190109ba97d373668ebf9 100644 (file)
--- a/include/linux/swap.h
+++ b/include/linux/swap.h
@@ -10,6 +10,7 @@
 #include <linux/node.h>
 #include <linux/fs.h>
 #include <linux/atomic.h>
+#include <linux/page-flags.h>
 #include <asm/page.h>
 
 struct notifier_block;
@@ -19,10 +20,13 @@ struct bio;
 #define SWAP_FLAG_PREFER       0x8000  /* set if swap priority specified */
 #define SWAP_FLAG_PRIO_MASK    0x7fff
 #define SWAP_FLAG_PRIO_SHIFT   0
-#define SWAP_FLAG_DISCARD      0x10000 /* discard swap cluster after use */
+#define SWAP_FLAG_DISCARD      0x10000 /* enable discard for swap */
+#define SWAP_FLAG_DISCARD_ONCE 0x20000 /* discard swap area at swapon-time */
+#define SWAP_FLAG_DISCARD_PAGES 0x40000 /* discard page-clusters after use */
 
 #define SWAP_FLAGS_VALID       (SWAP_FLAG_PRIO_MASK | SWAP_FLAG_PREFER | \
-                                SWAP_FLAG_DISCARD)
+                                SWAP_FLAG_DISCARD | SWAP_FLAG_DISCARD_ONCE | \
+                                SWAP_FLAG_DISCARD_PAGES)
 
 static inline int current_is_kswapd(void)
 {
@@ -146,14 +150,16 @@ struct swap_extent {
 enum {
        SWP_USED        = (1 << 0),     /* is slot in swap_info[] used? */
        SWP_WRITEOK     = (1 << 1),     /* ok to write to this swap?    */
-       SWP_DISCARDABLE = (1 << 2),     /* swapon+blkdev support discard */
+       SWP_DISCARDABLE = (1 << 2),     /* blkdev support discard */
        SWP_DISCARDING  = (1 << 3),     /* now discarding a free cluster */
        SWP_SOLIDSTATE  = (1 << 4),     /* blkdev seeks are cheap */
        SWP_CONTINUED   = (1 << 5),     /* swap_map has count continuation */
        SWP_BLKDEV      = (1 << 6),     /* its a block device */
        SWP_FILE        = (1 << 7),     /* set after swap_activate success */
+       SWP_AREA_DISCARD = (1 << 8),    /* single-time swap area discards */
+       SWP_PAGE_DISCARD = (1 << 9),    /* freed swap page-cluster discards */
                                        /* add others here before... */
-       SWP_SCANNING    = (1 << 8),     /* refcount in scan_swap_map */
+       SWP_SCANNING    = (1 << 10),    /* refcount in scan_swap_map */
 };
 
 #define SWAP_CLUSTER_MAX 32UL
@@ -233,8 +239,8 @@ extern unsigned long nr_free_pagecache_pages(void);
 
 
 /* linux/mm/swap.c */
-extern void __lru_cache_add(struct page *, enum lru_list lru);
-extern void lru_cache_add_lru(struct page *, enum lru_list lru);
+extern void __lru_cache_add(struct page *);
+extern void lru_cache_add(struct page *);
 extern void lru_add_page_tail(struct page *page, struct page *page_tail,
                         struct lruvec *lruvec, struct list_head *head);
 extern void activate_page(struct page *);
@@ -254,12 +260,14 @@ extern void add_page_to_unevictable_list(struct page *page);
  */
 static inline void lru_cache_add_anon(struct page *page)
 {
-       __lru_cache_add(page, LRU_INACTIVE_ANON);
+       ClearPageActive(page);
+       __lru_cache_add(page);
 }
 
 static inline void lru_cache_add_file(struct page *page)
 {
-       __lru_cache_add(page, LRU_INACTIVE_FILE);
+       ClearPageActive(page);
+       __lru_cache_add(page);
 }
 
 /* linux/mm/vmscan.c */