Merge branch 'ttm-fixes-3.13' of git://people.freedesktop.org/~thomash/linux into...

[cascardo/linux.git] / include / linux / shrinker.h

diff --git a/include/linux/shrinker.h b/include/linux/shrinker.h
index 76f520c..68c0970 100644 (file)
--- a/include/linux/shrinker.h
+++ b/include/linux/shrinker.h
@@ -7,29 +7,27 @@
  *
  * The 'gfpmask' refers to the allocation we are currently trying to
  * fulfil.
- *
- * Note that 'shrink' will be passed nr_to_scan == 0 when the VM is
- * querying the cache size, so a fastpath for that case is appropriate.
  */
 struct shrink_control {
        gfp_t gfp_mask;
 
-       /* How many slab objects shrinker() should scan and try to reclaim */
+       /*
+        * How many objects scan_objects should scan and try to reclaim.
+        * This is reset before every call, so it is safe for callees
+        * to modify.
+        */
        unsigned long nr_to_scan;
 
        /* shrink from these nodes */
        nodemask_t nodes_to_scan;
+       /* current node being shrunk (for NUMA aware shrinkers) */
+       int nid;
 };
 
 #define SHRINK_STOP (~0UL)
 /*
  * A callback you can register to apply pressure to ageable caches.
  *
- * @shrink() should look through the least-recently-used 'nr_to_scan' entries
- * and attempt to free them up.  It should return the number of objects which
- * remain in the cache.  If it returns -1, it means it cannot do any scanning at
- * this time (eg. there is a risk of deadlock).
- *
  * @count_objects should return the number of freeable items in the cache. If
  * there are no objects to free or the number of freeable items cannot be
  * determined, it should return 0. No deadlock checks should be done during the
@@ -44,9 +42,10 @@ struct shrink_control {
  * due to potential deadlocks. If SHRINK_STOP is returned, then no further
  * attempts to call the @scan_objects will be made from the current reclaim
  * context.
+ *
+ * @flags determine the shrinker abilities, like numa awareness
  */
 struct shrinker {
-       int (*shrink)(struct shrinker *, struct shrink_control *sc);
        unsigned long (*count_objects)(struct shrinker *,
                                       struct shrink_control *sc);
        unsigned long (*scan_objects)(struct shrinker *,
@@ -54,12 +53,18 @@ struct shrinker {
 
        int seeks;      /* seeks to recreate an obj */
        long batch;     /* reclaim batch size, 0 = default */
+       unsigned long flags;
 
        /* These are for internal use */
        struct list_head list;
-       atomic_long_t nr_in_batch; /* objs pending delete */
+       /* objs pending delete, per node */
+       atomic_long_t *nr_deferred;
 };
 #define DEFAULT_SEEKS 2 /* A good number if you don't know better. */
-extern void register_shrinker(struct shrinker *);
+
+/* Flags */
+#define SHRINKER_NUMA_AWARE (1 << 0)
+
+extern int register_shrinker(struct shrinker *);
 extern void unregister_shrinker(struct shrinker *);
 #endif