mm/hmm: remove redundant variable align_end

[sfrench/cifs-2.6.git] / mm / swap_slots.c

diff --git a/mm/swap_slots.c b/mm/swap_slots.c
index d81cfc5a43d5083c4d3eb7273bcf10e606c2eb79..bebc19292018f355b4e8f500e985c71e4ea3d9e4 100644 (file)
--- a/mm/swap_slots.c
+++ b/mm/swap_slots.c
@@ -149,6 +149,13 @@ static int alloc_swap_slot_cache(unsigned int cpu)
        cache->nr = 0;
        cache->cur = 0;
        cache->n_ret = 0;
+       /*
+        * We initialized alloc_lock and free_lock earlier.  We use
+        * !cache->slots or !cache->slots_ret to know if it is safe to acquire
+        * the corresponding lock and use the cache.  Memory barrier below
+        * ensures the assumption.
+        */
+       mb();
        cache->slots = slots;
        slots = NULL;
        cache->slots_ret = slots_ret;
@@ -275,7 +282,7 @@ int free_swap_slot(swp_entry_t entry)
        struct swap_slots_cache *cache;
 
        cache = raw_cpu_ptr(&swp_slots);
-       if (use_swap_slot_cache && cache->slots_ret) {
+       if (likely(use_swap_slot_cache && cache->slots_ret)) {
                spin_lock_irq(&cache->free_lock);
                /* Swap slots cache may be deactivated before acquiring lock */
                if (!use_swap_slot_cache || !cache->slots_ret) {
@@ -326,7 +333,7 @@ swp_entry_t get_swap_page(struct page *page)
         */
        cache = raw_cpu_ptr(&swp_slots);
 
-       if (check_cache_active()) {
+       if (likely(check_cache_active() && cache->slots)) {
                mutex_lock(&cache->alloc_lock);
                if (cache->slots) {
 repeat: