mm/memcg: warning on !memcg after readahead page charged

[linux-2.6-microblaze.git] / mm / swapfile.c

diff --git a/mm/swapfile.c b/mm/swapfile.c
index 1c0a829..9fffc5a 100644 (file)
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -1042,16 +1042,18 @@ int get_swap_pages(int n_goal, swp_entry_t swp_entries[], int entry_size)
        /* Only single cluster request supported */
        WARN_ON_ONCE(n_goal > 1 && size == SWAPFILE_CLUSTER);
 
+       spin_lock(&swap_avail_lock);
+
        avail_pgs = atomic_long_read(&nr_swap_pages) / size;
-       if (avail_pgs <= 0)
+       if (avail_pgs <= 0) {
+               spin_unlock(&swap_avail_lock);
                goto noswap;
+       }
 
        n_goal = min3((long)n_goal, (long)SWAP_BATCH, avail_pgs);
 
        atomic_long_sub(n_goal * size, &nr_swap_pages);
 
-       spin_lock(&swap_avail_lock);
-
 start_over:
        node = numa_node_id();
        plist_for_each_entry_safe(si, next, &swap_avail_heads[node], avail_lists[node]) {
@@ -1125,14 +1127,13 @@ swp_entry_t get_swap_page_of_type(int type)
 
        spin_lock(&si->lock);
        if (si->flags & SWP_WRITEOK) {
-               atomic_long_dec(&nr_swap_pages);
                /* This is called for allocating swap entry, not cache */
                offset = scan_swap_map(si, 1);
                if (offset) {
+                       atomic_long_dec(&nr_swap_pages);
                        spin_unlock(&si->lock);
                        return swp_entry(type, offset);
                }
-               atomic_long_inc(&nr_swap_pages);
        }
        spin_unlock(&si->lock);
 fail: