RDS: Do not mask address when pinning pages
[linux-2.6.git] / mm / page_cgroup.c
index 672089d..5bffada 100644 (file)
@@ -9,6 +9,7 @@
 #include <linux/vmalloc.h>
 #include <linux/cgroup.h>
 #include <linux/swapops.h>
+#include <linux/kmemleak.h>
 
 static void __meminit
 __init_page_cgroup(struct page_cgroup *pc, unsigned long pfn)
@@ -116,10 +117,22 @@ static int __init_refok init_section_page_cgroup(unsigned long pfn)
                nid = page_to_nid(pfn_to_page(pfn));
                table_size = sizeof(struct page_cgroup) * PAGES_PER_SECTION;
                VM_BUG_ON(!slab_is_available());
-               base = kmalloc_node(table_size,
+               if (node_state(nid, N_HIGH_MEMORY)) {
+                       base = kmalloc_node(table_size,
                                GFP_KERNEL | __GFP_NOWARN, nid);
-               if (!base)
-                       base = vmalloc_node(table_size, nid);
+                       if (!base)
+                               base = vmalloc_node(table_size, nid);
+               } else {
+                       base = kmalloc(table_size, GFP_KERNEL | __GFP_NOWARN);
+                       if (!base)
+                               base = vmalloc(table_size);
+               }
+               /*
+                * The value stored in section->page_cgroup is (base - pfn)
+                * and it does not point to the memory block allocated above,
+                * causing kmemleak false positives.
+                */
+               kmemleak_not_leak(base);
        } else {
                /*
                 * We don't have to allocate page_cgroup again, but
@@ -278,6 +291,7 @@ static DEFINE_MUTEX(swap_cgroup_mutex);
 struct swap_cgroup_ctrl {
        struct page **map;
        unsigned long length;
+       spinlock_t      lock;
 };
 
 struct swap_cgroup_ctrl swap_cgroup_ctrl[MAX_SWAPFILES];
@@ -311,8 +325,6 @@ static int swap_cgroup_prepare(int type)
        struct swap_cgroup_ctrl *ctrl;
        unsigned long idx, max;
 
-       if (!do_swap_account)
-               return 0;
        ctrl = &swap_cgroup_ctrl[type];
 
        for (idx = 0; idx < ctrl->length; idx++) {
@@ -331,6 +343,43 @@ not_enough_page:
 }
 
 /**
+ * swap_cgroup_cmpxchg - cmpxchg mem_cgroup's id for this swp_entry.
+ * @end: swap entry to be cmpxchged
+ * @old: old id
+ * @new: new id
+ *
+ * Returns old id at success, 0 at failure.
+ * (There is no mem_cgroup useing 0 as its id)
+ */
+unsigned short swap_cgroup_cmpxchg(swp_entry_t ent,
+                                       unsigned short old, unsigned short new)
+{
+       int type = swp_type(ent);
+       unsigned long offset = swp_offset(ent);
+       unsigned long idx = offset / SC_PER_PAGE;
+       unsigned long pos = offset & SC_POS_MASK;
+       struct swap_cgroup_ctrl *ctrl;
+       struct page *mappage;
+       struct swap_cgroup *sc;
+       unsigned long flags;
+       unsigned short retval;
+
+       ctrl = &swap_cgroup_ctrl[type];
+
+       mappage = ctrl->map[idx];
+       sc = page_address(mappage);
+       sc += pos;
+       spin_lock_irqsave(&ctrl->lock, flags);
+       retval = sc->id;
+       if (retval == old)
+               sc->id = new;
+       else
+               retval = 0;
+       spin_unlock_irqrestore(&ctrl->lock, flags);
+       return retval;
+}
+
+/**
  * swap_cgroup_record - record mem_cgroup for this swp_entry.
  * @ent: swap entry to be recorded into
  * @mem: mem_cgroup to be recorded
@@ -348,17 +397,17 @@ unsigned short swap_cgroup_record(swp_entry_t ent, unsigned short id)
        struct page *mappage;
        struct swap_cgroup *sc;
        unsigned short old;
-
-       if (!do_swap_account)
-               return 0;
+       unsigned long flags;
 
        ctrl = &swap_cgroup_ctrl[type];
 
        mappage = ctrl->map[idx];
        sc = page_address(mappage);
        sc += pos;
+       spin_lock_irqsave(&ctrl->lock, flags);
        old = sc->id;
        sc->id = id;
+       spin_unlock_irqrestore(&ctrl->lock, flags);
 
        return old;
 }
@@ -380,9 +429,6 @@ unsigned short lookup_swap_cgroup(swp_entry_t ent)
        struct swap_cgroup *sc;
        unsigned short ret;
 
-       if (!do_swap_account)
-               return 0;
-
        ctrl = &swap_cgroup_ctrl[type];
        mappage = ctrl->map[idx];
        sc = page_address(mappage);
@@ -413,6 +459,7 @@ int swap_cgroup_swapon(int type, unsigned long max_pages)
        mutex_lock(&swap_cgroup_mutex);
        ctrl->length = length;
        ctrl->map = array;
+       spin_lock_init(&ctrl->lock);
        if (swap_cgroup_prepare(type)) {
                /* memory shortage */
                ctrl->map = NULL;