mm: introduce zone_reclaim struct
KOSAKI Motohiro [Thu, 8 Jan 2009 02:08:15 +0000 (18:08 -0800)]
Add zone_reclam_stat struct for later enhancement.

A later patch uses this.  This patch doesn't any behavior change (yet).

Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Acked-by: Rik van Riel <riel@redhat.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

include/linux/mmzone.h
mm/page_alloc.c
mm/swap.c
mm/vmscan.c

index 35a7b5e..09c14e2 100644 (file)
@@ -263,6 +263,19 @@ enum zone_type {
 #error ZONES_SHIFT -- too many zones configured adjust calculation
 #endif
 
+struct zone_reclaim_stat {
+       /*
+        * The pageout code in vmscan.c keeps track of how many of the
+        * mem/swap backed and file backed pages are refeferenced.
+        * The higher the rotated/scanned ratio, the more valuable
+        * that cache is.
+        *
+        * The anon LRU stats live in [0], file LRU stats in [1]
+        */
+       unsigned long           recent_rotated[2];
+       unsigned long           recent_scanned[2];
+};
+
 struct zone {
        /* Fields commonly accessed by the page allocator */
        unsigned long           pages_min, pages_low, pages_high;
@@ -315,16 +328,7 @@ struct zone {
                unsigned long nr_scan;
        } lru[NR_LRU_LISTS];
 
-       /*
-        * The pageout code in vmscan.c keeps track of how many of the
-        * mem/swap backed and file backed pages are refeferenced.
-        * The higher the rotated/scanned ratio, the more valuable
-        * that cache is.
-        *
-        * The anon LRU stats live in [0], file LRU stats in [1]
-        */
-       unsigned long           recent_rotated[2];
-       unsigned long           recent_scanned[2];
+       struct zone_reclaim_stat reclaim_stat;
 
        unsigned long           pages_scanned;     /* since last reclaim */
        unsigned long           flags;             /* zone flags, see below */
index 7bf22e0..5675b30 100644 (file)
@@ -3523,10 +3523,10 @@ static void __paginginit free_area_init_core(struct pglist_data *pgdat,
                        INIT_LIST_HEAD(&zone->lru[l].list);
                        zone->lru[l].nr_scan = 0;
                }
-               zone->recent_rotated[0] = 0;
-               zone->recent_rotated[1] = 0;
-               zone->recent_scanned[0] = 0;
-               zone->recent_scanned[1] = 0;
+               zone->reclaim_stat.recent_rotated[0] = 0;
+               zone->reclaim_stat.recent_rotated[1] = 0;
+               zone->reclaim_stat.recent_scanned[0] = 0;
+               zone->reclaim_stat.recent_scanned[1] = 0;
                zap_zone_vm_stats(zone);
                zone->flags = 0;
                if (!size)
index 8a98a9c..26b07e7 100644 (file)
--- a/mm/swap.c
+++ b/mm/swap.c
@@ -157,6 +157,7 @@ void  rotate_reclaimable_page(struct page *page)
 void activate_page(struct page *page)
 {
        struct zone *zone = page_zone(page);
+       struct zone_reclaim_stat *reclaim_stat = &zone->reclaim_stat;
 
        spin_lock_irq(&zone->lru_lock);
        if (PageLRU(page) && !PageActive(page) && !PageUnevictable(page)) {
@@ -169,8 +170,8 @@ void activate_page(struct page *page)
                add_page_to_lru_list(zone, page, lru);
                __count_vm_event(PGACTIVATE);
 
-               zone->recent_rotated[!!file]++;
-               zone->recent_scanned[!!file]++;
+               reclaim_stat->recent_rotated[!!file]++;
+               reclaim_stat->recent_scanned[!!file]++;
        }
        spin_unlock_irq(&zone->lru_lock);
 }
@@ -385,6 +386,8 @@ void ____pagevec_lru_add(struct pagevec *pvec, enum lru_list lru)
 {
        int i;
        struct zone *zone = NULL;
+       struct zone_reclaim_stat *reclaim_stat = NULL;
+
        VM_BUG_ON(is_unevictable_lru(lru));
 
        for (i = 0; i < pagevec_count(pvec); i++) {
@@ -396,6 +399,7 @@ void ____pagevec_lru_add(struct pagevec *pvec, enum lru_list lru)
                        if (zone)
                                spin_unlock_irq(&zone->lru_lock);
                        zone = pagezone;
+                       reclaim_stat = &zone->reclaim_stat;
                        spin_lock_irq(&zone->lru_lock);
                }
                VM_BUG_ON(PageActive(page));
@@ -403,10 +407,10 @@ void ____pagevec_lru_add(struct pagevec *pvec, enum lru_list lru)
                VM_BUG_ON(PageLRU(page));
                SetPageLRU(page);
                file = is_file_lru(lru);
-               zone->recent_scanned[file]++;
+               reclaim_stat->recent_scanned[file]++;
                if (is_active_lru(lru)) {
                        SetPageActive(page);
-                       zone->recent_rotated[file]++;
+                       reclaim_stat->recent_rotated[file]++;
                }
                add_page_to_lru_list(zone, page, lru);
        }
index f75d924..03ca923 100644 (file)
@@ -130,6 +130,12 @@ static DECLARE_RWSEM(shrinker_rwsem);
 #define scan_global_lru(sc)    (1)
 #endif
 
+static struct zone_reclaim_stat *get_reclaim_stat(struct zone *zone,
+                                                 struct scan_control *sc)
+{
+       return &zone->reclaim_stat;
+}
+
 /*
  * Add a shrinker callback to be called from the vm
  */
@@ -1029,6 +1035,7 @@ static unsigned long shrink_inactive_list(unsigned long max_scan,
        struct pagevec pvec;
        unsigned long nr_scanned = 0;
        unsigned long nr_reclaimed = 0;
+       struct zone_reclaim_stat *reclaim_stat = get_reclaim_stat(zone, sc);
 
        pagevec_init(&pvec, 1);
 
@@ -1072,10 +1079,14 @@ static unsigned long shrink_inactive_list(unsigned long max_scan,
 
                if (scan_global_lru(sc)) {
                        zone->pages_scanned += nr_scan;
-                       zone->recent_scanned[0] += count[LRU_INACTIVE_ANON];
-                       zone->recent_scanned[0] += count[LRU_ACTIVE_ANON];
-                       zone->recent_scanned[1] += count[LRU_INACTIVE_FILE];
-                       zone->recent_scanned[1] += count[LRU_ACTIVE_FILE];
+                       reclaim_stat->recent_scanned[0] +=
+                                                     count[LRU_INACTIVE_ANON];
+                       reclaim_stat->recent_scanned[0] +=
+                                                     count[LRU_ACTIVE_ANON];
+                       reclaim_stat->recent_scanned[1] +=
+                                                     count[LRU_INACTIVE_FILE];
+                       reclaim_stat->recent_scanned[1] +=
+                                                     count[LRU_ACTIVE_FILE];
                }
                spin_unlock_irq(&zone->lru_lock);
 
@@ -1136,7 +1147,7 @@ static unsigned long shrink_inactive_list(unsigned long max_scan,
                        add_page_to_lru_list(zone, page, lru);
                        if (PageActive(page) && scan_global_lru(sc)) {
                                int file = !!page_is_file_cache(page);
-                               zone->recent_rotated[file]++;
+                               reclaim_stat->recent_rotated[file]++;
                        }
                        if (!pagevec_add(&pvec, page)) {
                                spin_unlock_irq(&zone->lru_lock);
@@ -1196,6 +1207,7 @@ static void shrink_active_list(unsigned long nr_pages, struct zone *zone,
        struct page *page;
        struct pagevec pvec;
        enum lru_list lru;
+       struct zone_reclaim_stat *reclaim_stat = get_reclaim_stat(zone, sc);
 
        lru_add_drain();
        spin_lock_irq(&zone->lru_lock);
@@ -1208,7 +1220,7 @@ static void shrink_active_list(unsigned long nr_pages, struct zone *zone,
         */
        if (scan_global_lru(sc)) {
                zone->pages_scanned += pgscanned;
-               zone->recent_scanned[!!file] += pgmoved;
+               reclaim_stat->recent_scanned[!!file] += pgmoved;
        }
 
        if (file)
@@ -1251,7 +1263,7 @@ static void shrink_active_list(unsigned long nr_pages, struct zone *zone,
         * pages in get_scan_ratio.
         */
        if (scan_global_lru(sc))
-               zone->recent_rotated[!!file] += pgmoved;
+               reclaim_stat->recent_rotated[!!file] += pgmoved;
 
        while (!list_empty(&l_inactive)) {
                page = lru_to_page(&l_inactive);
@@ -1344,6 +1356,7 @@ static void get_scan_ratio(struct zone *zone, struct scan_control *sc,
        unsigned long anon, file, free;
        unsigned long anon_prio, file_prio;
        unsigned long ap, fp;
+       struct zone_reclaim_stat *reclaim_stat = get_reclaim_stat(zone, sc);
 
        /* If we have no swap space, do not bother scanning anon pages. */
        if (nr_swap_pages <= 0) {
@@ -1376,17 +1389,17 @@ static void get_scan_ratio(struct zone *zone, struct scan_control *sc,
         *
         * anon in [0], file in [1]
         */
-       if (unlikely(zone->recent_scanned[0] > anon / 4)) {
+       if (unlikely(reclaim_stat->recent_scanned[0] > anon / 4)) {
                spin_lock_irq(&zone->lru_lock);
-               zone->recent_scanned[0] /= 2;
-               zone->recent_rotated[0] /= 2;
+               reclaim_stat->recent_scanned[0] /= 2;
+               reclaim_stat->recent_rotated[0] /= 2;
                spin_unlock_irq(&zone->lru_lock);
        }
 
-       if (unlikely(zone->recent_scanned[1] > file / 4)) {
+       if (unlikely(reclaim_stat->recent_scanned[1] > file / 4)) {
                spin_lock_irq(&zone->lru_lock);
-               zone->recent_scanned[1] /= 2;
-               zone->recent_rotated[1] /= 2;
+               reclaim_stat->recent_scanned[1] /= 2;
+               reclaim_stat->recent_rotated[1] /= 2;
                spin_unlock_irq(&zone->lru_lock);
        }
 
@@ -1402,11 +1415,11 @@ static void get_scan_ratio(struct zone *zone, struct scan_control *sc,
         * proportional to the fraction of recently scanned pages on
         * each list that were recently referenced and in active use.
         */
-       ap = (anon_prio + 1) * (zone->recent_scanned[0] + 1);
-       ap /= zone->recent_rotated[0] + 1;
+       ap = (anon_prio + 1) * (reclaim_stat->recent_scanned[0] + 1);
+       ap /= reclaim_stat->recent_rotated[0] + 1;
 
-       fp = (file_prio + 1) * (zone->recent_scanned[1] + 1);
-       fp /= zone->recent_rotated[1] + 1;
+       fp = (file_prio + 1) * (reclaim_stat->recent_scanned[1] + 1);
+       fp /= reclaim_stat->recent_rotated[1] + 1;
 
        /* Normalize to percentages */
        percent[0] = 100 * ap / (ap + fp + 1);