[PATCH] mm/zswap: Check all pool pages instead of one pool pages

[Cai Liu <cai.liu@samsung.com>]

zswap can support multiple swapfiles. So we need to check
all zbud pool pages in zswap.

Signed-off-by: Cai Liu <cai.liu@samsung.com>
---
 mm/zswap.c |   18 +++++++++++++++---
 1 file changed, 15 insertions(+), 3 deletions(-)

diff --git a/mm/zswap.c b/mm/zswap.c
index d93afa6..2438344 100644
--- a/mm/zswap.c
+++ b/mm/zswap.c
@@ -291,7 +291,6 @@ static void zswap_free_entry(struct zswap_tree *tree,
 	zbud_free(tree->pool, entry->handle);
 	zswap_entry_cache_free(entry);
 	atomic_dec(&zswap_stored_pages);
-	zswap_pool_pages = zbud_get_pool_size(tree->pool);
 }
 
 /* caller must hold the tree lock */
@@ -405,10 +404,24 @@ cleanup:
 /*********************************
 * helpers
 **********************************/
+static u64 get_zswap_pool_pages(void)
+{
+	int i;
+	u64 pool_pages = 0;
+
+	for (i = 0; i < MAX_SWAPFILES; i++) {
+		if (zswap_trees[i])
+			pool_pages += zbud_get_pool_size(zswap_trees[i]->pool);
+	}
+	zswap_pool_pages = pool_pages;
+
+	return pool_pages;
+}
+
 static bool zswap_is_full(void)
 {
 	return (totalram_pages * zswap_max_pool_percent / 100 <
-		zswap_pool_pages);
+		get_zswap_pool_pages());
 }
 
 /*********************************
@@ -716,7 +729,6 @@ static int zswap_frontswap_store(unsigned type, pgoff_t offset,
 
 	/* update stats */
 	atomic_inc(&zswap_stored_pages);
-	zswap_pool_pages = zbud_get_pool_size(tree->pool);
 
 	return 0;
 
-- 
1.7.10.4