mm: simplify code of swap.c

Clean up code and remove duplicate code.  Next patch will use
pagevec_lru_move_fn introduced here too.

Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 54 insertions, 47 deletions

diff --git a/mm/swap.c b/mm/swap.c
index c02f93611a84..ab498ea04ae3 100644
--- a/mm/swap.c
+++ b/mm/swap.c
@@ -178,15 +178,13 @@ void put_pages_list(struct list_head *pages)
 }
 EXPORT_SYMBOL(put_pages_list);
 
-/*
- * pagevec_move_tail() must be called with IRQ disabled.
- * Otherwise this may cause nasty races.
- */
-static void pagevec_move_tail(struct pagevec *pvec)
+static void pagevec_lru_move_fn(struct pagevec *pvec,
+                                void (*move_fn)(struct page *page, void *arg),
+                                void *arg)
 {
         int i;
-        int pgmoved = 0;
         struct zone *zone = NULL;
+        unsigned long flags = 0;
 
         for (i = 0; i < pagevec_count(pvec); i++) {
                 struct page *page = pvec->pages[i];
@@ -194,29 +192,49 @@ static void pagevec_move_tail(struct pagevec *pvec)
 
                 if (pagezone != zone) {
                         if (zone)
-                                spin_unlock(&zone->lru_lock);
+                                spin_unlock_irqrestore(&zone->lru_lock, flags);
                         zone = pagezone;
-                        spin_lock(&zone->lru_lock);
-                }
-                if (PageLRU(page) && !PageActive(page) && !PageUnevictable(page)) {
-                        int lru = page_lru_base_type(page);
-                        list_move_tail(&page->lru, &zone->lru[lru].list);
-                        pgmoved++;
+                        spin_lock_irqsave(&zone->lru_lock, flags);
                 }
+
+                (*move_fn)(page, arg);
         }
         if (zone)
-                spin_unlock(&zone->lru_lock);
-        __count_vm_events(PGROTATED, pgmoved);
-        release_pages(pvec->pages, pvec->nr, pvec->cold);
+                spin_unlock_irqrestore(&zone->lru_lock, flags);
+        release_pages(pvec->pages, pagevec_count(pvec), pvec->cold);
         pagevec_reinit(pvec);
 }
 
+static void pagevec_move_tail_fn(struct page *page, void *arg)
+{
+        int *pgmoved = arg;
+        struct zone *zone = page_zone(page);
+
+        if (PageLRU(page) && !PageActive(page) && !PageUnevictable(page)) {
+                int lru = page_lru_base_type(page);
+                list_move_tail(&page->lru, &zone->lru[lru].list);
+                (*pgmoved)++;
+        }
+}
+
+/*
+ * pagevec_move_tail() must be called with IRQ disabled.
+ * Otherwise this may cause nasty races.
+ */
+static void pagevec_move_tail(struct pagevec *pvec)
+{
+        int pgmoved = 0;
+
+        pagevec_lru_move_fn(pvec, pagevec_move_tail_fn, &pgmoved);
+        __count_vm_events(PGROTATED, pgmoved);
+}
+
 /*
  * Writeback is about to end against a page which has been marked for immediate
  * reclaim.  If it still appears to be reclaimable, move it to the tail of the
  * inactive list.
  */
-void  rotate_reclaimable_page(struct page *page)
+void rotate_reclaimable_page(struct page *page)
 {
         if (!PageLocked(page) && !PageDirty(page) && !PageActive(page) &&
             !PageUnevictable(page) && PageLRU(page)) {
@@ -516,44 +534,33 @@ void lru_add_page_tail(struct zone* zone,
         }
 }
 
+static void ____pagevec_lru_add_fn(struct page *page, void *arg)
+{
+        enum lru_list lru = (enum lru_list)arg;
+        struct zone *zone = page_zone(page);
+        int file = is_file_lru(lru);
+        int active = is_active_lru(lru);
+
+        VM_BUG_ON(PageActive(page));
+        VM_BUG_ON(PageUnevictable(page));
+        VM_BUG_ON(PageLRU(page));
+
+        SetPageLRU(page);
+        if (active)
+                SetPageActive(page);
+        update_page_reclaim_stat(zone, page, file, active);
+        add_page_to_lru_list(zone, page, lru);
+}
+
 /*
  * Add the passed pages to the LRU, then drop the caller's refcount
  * on them.  Reinitialises the caller's pagevec.
  */
 void ____pagevec_lru_add(struct pagevec *pvec, enum lru_list lru)
 {
-        int i;
-        struct zone *zone = NULL;
-
         VM_BUG_ON(is_unevictable_lru(lru));
 
-        for (i = 0; i < pagevec_count(pvec); i++) {
-                struct page *page = pvec->pages[i];
-                struct zone *pagezone = page_zone(page);
-                int file;
-                int active;
-
-                if (pagezone != zone) {
-                        if (zone)
-                                spin_unlock_irq(&zone->lru_lock);
-                        zone = pagezone;
-                        spin_lock_irq(&zone->lru_lock);
-                }
-                VM_BUG_ON(PageActive(page));
-                VM_BUG_ON(PageUnevictable(page));
-                VM_BUG_ON(PageLRU(page));
-                SetPageLRU(page);
-                active = is_active_lru(lru);
-                file = is_file_lru(lru);
-                if (active)
-                        SetPageActive(page);
-                update_page_reclaim_stat(zone, page, file, active);
-                add_page_to_lru_list(zone, page, lru);
-        }
-        if (zone)
-                spin_unlock_irq(&zone->lru_lock);
-        release_pages(pvec->pages, pvec->nr, pvec->cold);
-        pagevec_reinit(pvec);
+        pagevec_lru_move_fn(pvec, ____pagevec_lru_add_fn, (void *)lru);
 }
 
 EXPORT_SYMBOL(____pagevec_lru_add);