[PATCH][8/8] mm: lru interface change
From: Stone Wang
Date: Mon Mar 20 2006 - 08:36:30 EST
Add Wired list to LRU.
Add PG_Wired bit to page.
Signed-off-by: Shaoping Wang <pwstone@xxxxxxxxx>
--
include/linux/mm_inline.h | 25 +++++++++++++
include/linux/mmzone.h | 2 +
include/linux/page-flags.h | 9 +++++
include/linux/swap.h | 2 +
mm/page_alloc.c | 4 +-
mm/swap.c | 81 +++++++++++++++++++++++++++++++++++++--------
6 files changed, 107 insertions(+), 16 deletions(-)
diff -urN linux-2.6.15.orig/include/linux/mm_inline.h
linux-2.6.15/include/linux/mm_inline.h
--- linux-2.6.15.orig/include/linux/mm_inline.h 2006-01-02
22:21:10.000000000 -0500
+++ linux-2.6.15/include/linux/mm_inline.h 2006-03-07 01:56:10.000000000 -0500
@@ -1,3 +1,9 @@
+/*
+ * There are 3 per-zone lists in LRU:
+ * Active: pages which were accessed more frequently.
+ * Inactive: pages accessed less frequently.
+ * Wired: pages mlocked by some tasks.
+ */
static inline void
add_page_to_active_list(struct zone *zone, struct page *page)
@@ -14,6 +20,13 @@
}
static inline void
+add_page_to_wired_list(struct zone *zone, struct page *page)
+{
+ list_add(&page->lru, &zone->wired_list);
+ zone->nr_wired++;
+}
+
+static inline void
del_page_from_active_list(struct zone *zone, struct page *page)
{
list_del(&page->lru);
@@ -28,10 +41,20 @@
}
static inline void
+del_page_from_wired_list(struct zone *zone, struct page *page)
+{
+ list_del(&page->lru);
+ zone->nr_wired--;
+}
+
+static inline void
del_page_from_lru(struct zone *zone, struct page *page)
{
list_del(&page->lru);
- if (PageActive(page)) {
+ if(PageWired(page)){
+ ClearPageWired(page);
+ zone->nr_wired--;
+ } else if (PageActive(page)) {
ClearPageActive(page);
zone->nr_active--;
} else {
diff -urN linux-2.6.15.orig/include/linux/mmzone.h
linux-2.6.15/include/linux/mmzone.h
--- linux-2.6.15.orig/include/linux/mmzone.h 2006-01-02 22:21:10.000000000 -0500
+++ linux-2.6.15/include/linux/mmzone.h 2006-03-07 01:58:26.000000000 -0500
@@ -143,10 +143,12 @@
spinlock_t lru_lock;
struct list_head active_list;
struct list_head inactive_list;
+ struct list_head wired_list; /* Pages wired. */
unsigned long nr_scan_active;
unsigned long nr_scan_inactive;
unsigned long nr_active;
unsigned long nr_inactive;
+ unsigned long nr_wired;
unsigned long pages_scanned; /* since last reclaim */
int all_unreclaimable; /* All pages pinned */
diff -urN linux-2.6.15.orig/include/linux/page-flags.h
linux-2.6.15/include/linux/page-flags.h
--- linux-2.6.15.orig/include/linux/page-flags.h 2006-01-02
22:21:10.000000000 -0500
+++ linux-2.6.15/include/linux/page-flags.h 2006-03-06 06:30:07.000000000 -0500
@@ -76,6 +76,8 @@
#define PG_nosave_free 18 /* Free, should not be written */
#define PG_uncached 19 /* Page has been mapped as uncached */
+#define PG_wired 20 /* Page is on Wired list */
+
/*
* Global page accounting. One instance per CPU. Only unsigned longs are
* allowed.
@@ -198,7 +200,14 @@
#define __ClearPageDirty(page) __clear_bit(PG_dirty, &(page)->flags)
#define TestClearPageDirty(page) test_and_clear_bit(PG_dirty, &(page)->flags)
+#define SetPageWired(page) set_bit(PG_wired, &(page)->flags)
+#define ClearPageWired(page) clear_bit(PG_wired,&(page)->flags)
+#define PageWired(page) test_bit(PG_wired, &(page)->flags)
+#define TestSetPageWired(page) test_and_set_bit(PG_wired, &(page)->flags)
+#define TestClearPageWired(page) test_and_clear_bit(PG_wired, &(page)->flags)
+
#define SetPageLRU(page) set_bit(PG_lru, &(page)->flags)
+#define ClearPageLRU(page) clear_bit(PG_lru, &(page)->flags)
#define PageLRU(page) test_bit(PG_lru, &(page)->flags)
#define TestSetPageLRU(page) test_and_set_bit(PG_lru, &(page)->flags)
#define TestClearPageLRU(page) test_and_clear_bit(PG_lru, &(page)->flags)
diff -urN linux-2.6.15.orig/include/linux/swap.h
linux-2.6.15/include/linux/swap.h
--- linux-2.6.15.orig/include/linux/swap.h 2006-01-02 22:21:10.000000000 -0500
+++ linux-2.6.15/include/linux/swap.h 2006-03-06 06:30:07.000000000 -0500
@@ -165,6 +165,8 @@
extern void FASTCALL(lru_cache_add(struct page *));
extern void FASTCALL(lru_cache_add_active(struct page *));
extern void FASTCALL(activate_page(struct page *));
+extern void FASTCALL(wire_page(struct page *));
+extern void FASTCALL(unwire_page(struct page *));
extern void FASTCALL(mark_page_accessed(struct page *));
extern void lru_add_drain(void);
extern int rotate_reclaimable_page(struct page *page);
diff -urN linux-2.6.15.orig/mm/swap.c linux-2.6.15/mm/swap.c
--- linux-2.6.15.orig/mm/swap.c 2006-01-02 22:21:10.000000000 -0500
+++ linux-2.6.15/mm/swap.c 2006-03-07 11:45:37.000000000 -0500
@@ -110,6 +110,44 @@
spin_unlock_irq(&zone->lru_lock);
}
+/* Wire the page; if the page is in LRU,
+ * try move it to Wired list.
+ */
+void fastcall wire_page(struct page *page)
+{
+ struct zone *zone = page_zone(page);
+
+ spin_lock_irq(&zone->lru_lock);
+ page->wired_count ++;
+ if(!PageWired(page)){
+ if(PageLRU(page)){
+ del_page_from_lru(zone, page);
+ add_page_to_wired_list(zone,page);
+ SetPageWired(page);
+ }
+ }
+ spin_unlock_irq(&zone->lru_lock);
+}
+
+/* Unwire the page.
+ * If it isnt wired by any process, try move it to active list.
+ */
+void fastcall unwire_page(struct page *page)
+{
+ struct zone *zone = page_zone(page);
+
+ spin_lock_irq(&zone->lru_lock);
+ page->wired_count --;
+ if(!page->wired_count){
+ if(PageLRU(page) && TestClearPageWired(page)){
+ del_page_from_wired_list(zone,page);
+ add_page_to_active_list(zone,page);
+ SetPageActive(page);
+ }
+ }
+ spin_unlock_irq(&zone->lru_lock);
+}
+
/*
* Mark a page as having seen activity.
*
@@ -119,11 +157,13 @@
*/
void fastcall mark_page_accessed(struct page *page)
{
- if (!PageActive(page) && PageReferenced(page) && PageLRU(page)) {
- activate_page(page);
- ClearPageReferenced(page);
- } else if (!PageReferenced(page)) {
- SetPageReferenced(page);
+ if(!PageWired(page)) {
+ if (!PageActive(page) && PageReferenced(page) && PageLRU(page)) {
+ activate_page(page);
+ ClearPageReferenced(page);
+ } else if (!PageReferenced(page)) {
+ SetPageReferenced(page);
+ }
}
}
@@ -178,13 +218,15 @@
struct zone *zone = page_zone(page);
spin_lock_irqsave(&zone->lru_lock, flags);
- if (TestClearPageLRU(page))
- del_page_from_lru(zone, page);
- if (page_count(page) != 0)
- page = NULL;
+ if(!PageWired(page)) {
+ if (TestClearPageLRU(page))
+ del_page_from_lru(zone, page);
+ if (page_count(page) != 0)
+ page = NULL;
+ if (page)
+ free_hot_page(page);
+ }
spin_unlock_irqrestore(&zone->lru_lock, flags);
- if (page)
- free_hot_page(page);
}
EXPORT_SYMBOL(__page_cache_release);
@@ -214,7 +256,8 @@
if (!put_page_testzero(page))
continue;
-
+ if(PageWired(page))
+ continue;
pagezone = page_zone(page);
if (pagezone != zone) {
if (zone)
@@ -301,7 +344,12 @@
}
if (TestSetPageLRU(page))
BUG();
- add_page_to_inactive_list(zone, page);
+ if(!page->wired_count)
+ add_page_to_inactive_list(zone, page);
+ else {
+ SetPageWired(page);
+ add_page_to_wired_list(zone,page);
+ }
}
if (zone)
spin_unlock_irq(&zone->lru_lock);
@@ -330,7 +378,12 @@
BUG();
if (TestSetPageActive(page))
BUG();
- add_page_to_active_list(zone, page);
+ if(!page->wired_count)
+ add_page_to_active_list(zone, page);
+ else{
+ SetPageWired(page);
+ add_page_to_wired_list(zone,page);
+ }
}
if (zone)
spin_unlock_irq(&zone->lru_lock);
diff -urN linux-2.6.15.orig/mm/page_alloc.c linux-2.6.15/mm/page_alloc.c
--- linux-2.6.15.orig/mm/page_alloc.c 2006-01-02 22:21:10.000000000 -0500
+++ linux-2.6.15/mm/page_alloc.c 2006-03-06 06:30:08.000000000 -0500
@@ -348,7 +348,8 @@
1 << PG_slab |
1 << PG_swapcache |
1 << PG_writeback |
- 1 << PG_reserved )))
+ 1 << PG_reserved |
+ 1 << PG_wired )))
bad_page(function, page);
if (PageDirty(page))
__ClearPageDirty(page);
@@ -481,6 +482,7 @@
1 << PG_private |
1 << PG_locked |
1 << PG_active |
+ 1 << PG_wired |
1 << PG_dirty |
1 << PG_reclaim |
1 << PG_slab |
-
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