[PATCH RFC 04/10] xen/balloon: factor out function to update balloon stats

[Wei Liu <wei.liu2@citrix.com>]

Signed-off-by: Wei Liu <wei.liu2@citrix.com>
---
 drivers/xen/balloon.c |   22 +++++++++++++---------
 1 file changed, 13 insertions(+), 9 deletions(-)

diff --git a/drivers/xen/balloon.c b/drivers/xen/balloon.c
index d8055f0..04e12b4 100644
--- a/drivers/xen/balloon.c
+++ b/drivers/xen/balloon.c
@@ -107,17 +107,24 @@ static void scrub_page(struct page *page)
 #endif
 }
 
+static inline void update_balloon_stats(struct page *page, int count)
+{
+	if (PageHighMem(page))
+		xen_balloon.balloon_stats.balloon_high += count;
+	else
+		xen_balloon.balloon_stats.balloon_low += count;
+}
+
 /* balloon_append: add the given page to the balloon. */
 static void __balloon_append(struct page *page)
 {
 	/* Lowmem is re-populated first, so highmem pages go at list tail. */
-	if (PageHighMem(page)) {
+	if (PageHighMem(page))
 		list_add_tail(&page->lru, &xen_balloon.ballooned_pages);
-		xen_balloon.balloon_stats.balloon_high++;
-	} else {
+	else
 		list_add(&page->lru, &xen_balloon.ballooned_pages);
-		xen_balloon.balloon_stats.balloon_low++;
-	}
+
+	update_balloon_stats(page, 1);
 }
 
 static void balloon_append(struct page *page)
@@ -142,10 +149,7 @@ static struct page *balloon_retrieve(bool prefer_highmem)
 				  struct page, lru);
 	list_del(&page->lru);
 
-	if (PageHighMem(page))
-		xen_balloon.balloon_stats.balloon_high--;
-	else
-		xen_balloon.balloon_stats.balloon_low--;
+	update_balloon_stats(page, -1);
 
 	adjust_managed_page_count(page, 1);
 
-- 
1.7.10.4