mempolicy: use MPOL_F_LOCAL to Indicate Preferred Local Policy

[pandora-kernel.git] / include / linux / mempolicy.h

diff --git a/include/linux/mempolicy.h b/include/linux/mempolicy.h
index 02b11ef..b0fab9e 100644 (file)
--- a/include/linux/mempolicy.h
+++ b/include/linux/mempolicy.h
@@ -44,6 +44,14 @@ enum {
 #define MPOL_MF_MOVE_ALL (1<<2)        /* Move every page to conform to mapping */
 #define MPOL_MF_INTERNAL (1<<3)        /* Internal flags start here */
 
+/*
+ * Internal flags that share the struct mempolicy flags word with
+ * "mode flags".  These flags are allocated from bit 0 up, as they
+ * are never OR'ed into the mode in mempolicy API arguments.
+ */
+#define MPOL_F_SHARED  (1 << 0)        /* identify shared policies */
+#define MPOL_F_LOCAL   (1 << 1)        /* preferred local allocation */
+
 #ifdef __KERNEL__
 
 #include <linux/mmzone.h>
@@ -52,7 +60,6 @@ enum {
 #include <linux/spinlock.h>
 #include <linux/nodemask.h>
 
-struct vm_area_struct;
 struct mm_struct;
 
 #ifdef CONFIG_NUMA
@@ -72,16 +79,16 @@ struct mm_struct;
  *
  * Freeing policy:
  * Mempolicy objects are reference counted.  A mempolicy will be freed when
- * mpol_free() decrements the reference count to zero.
+ * mpol_put() decrements the reference count to zero.
  *
- * Copying policy objects:
- * mpol_copy() allocates a new mempolicy and copies the specified mempolicy
+ * Duplicating policy objects:
+ * mpol_dup() allocates a new mempolicy and copies the specified mempolicy
  * to the new storage.  The reference count of the new object is initialized
- * to 1, representing the caller of mpol_copy().
+ * to 1, representing the caller of mpol_dup().
  */
 struct mempolicy {
        atomic_t refcnt;
-       unsigned short policy;  /* See MPOL_* above */
+       unsigned short mode;    /* See MPOL_* above */
        unsigned short flags;   /* See set_mempolicy() MPOL_F_* above */
        union {
                short            preferred_node; /* preferred */
@@ -99,18 +106,43 @@ struct mempolicy {
  * The default fast path of a NULL MPOL_DEFAULT policy is always inlined.
  */
 
-extern void __mpol_free(struct mempolicy *pol);
-static inline void mpol_free(struct mempolicy *pol)
+extern void __mpol_put(struct mempolicy *pol);
+static inline void mpol_put(struct mempolicy *pol)
 {
        if (pol)
-               __mpol_free(pol);
+               __mpol_put(pol);
+}
+
+/*
+ * Does mempolicy pol need explicit unref after use?
+ * Currently only needed for shared policies.
+ */
+static inline int mpol_needs_cond_ref(struct mempolicy *pol)
+{
+       return (pol && (pol->flags & MPOL_F_SHARED));
+}
+
+static inline void mpol_cond_put(struct mempolicy *pol)
+{
+       if (mpol_needs_cond_ref(pol))
+               __mpol_put(pol);
 }
 
-extern struct mempolicy *__mpol_copy(struct mempolicy *pol);
-static inline struct mempolicy *mpol_copy(struct mempolicy *pol)
+extern struct mempolicy *__mpol_cond_copy(struct mempolicy *tompol,
+                                         struct mempolicy *frompol);
+static inline struct mempolicy *mpol_cond_copy(struct mempolicy *tompol,
+                                               struct mempolicy *frompol)
+{
+       if (!frompol)
+               return frompol;
+       return __mpol_cond_copy(tompol, frompol);
+}
+
+extern struct mempolicy *__mpol_dup(struct mempolicy *pol);
+static inline struct mempolicy *mpol_dup(struct mempolicy *pol)
 {
        if (pol)
-               pol = __mpol_copy(pol);
+               pol = __mpol_dup(pol);
        return pol;
 }
 
@@ -131,10 +163,6 @@ static inline int mpol_equal(struct mempolicy *a, struct mempolicy *b)
        return __mpol_equal(a, b);
 }
 
-/* Could later add inheritance of the process policy here. */
-
-#define mpol_set_vma_default(vma) ((vma)->vm_policy = NULL)
-
 /*
  * Tree of shared policies for a shared memory region.
  * Maintain the policies in a pseudo mm that contains vmas. The vmas
@@ -154,7 +182,7 @@ struct shared_policy {
        spinlock_t lock;
 };
 
-void mpol_shared_policy_init(struct shared_policy *info, unsigned short policy,
+void mpol_shared_policy_init(struct shared_policy *info, unsigned short mode,
                                unsigned short flags, nodemask_t *nodes);
 int mpol_set_shared_policy(struct shared_policy *info,
                                struct vm_area_struct *vma,
@@ -170,7 +198,6 @@ extern void mpol_rebind_task(struct task_struct *tsk,
 extern void mpol_rebind_mm(struct mm_struct *mm, nodemask_t *new);
 extern void mpol_fix_fork_child_flag(struct task_struct *p);
 
-extern struct mempolicy default_policy;
 extern struct zonelist *huge_zonelist(struct vm_area_struct *vma,
                                unsigned long addr, gfp_t gfp_flags,
                                struct mempolicy **mpol, nodemask_t **nodemask);
@@ -196,17 +223,25 @@ static inline int mpol_equal(struct mempolicy *a, struct mempolicy *b)
        return 1;
 }
 
-#define mpol_set_vma_default(vma) do {} while(0)
+static inline void mpol_put(struct mempolicy *p)
+{
+}
+
+static inline void mpol_cond_put(struct mempolicy *pol)
+{
+}
 
-static inline void mpol_free(struct mempolicy *p)
+static inline struct mempolicy *mpol_cond_copy(struct mempolicy *to,
+                                               struct mempolicy *from)
 {
+       return from;
 }
 
 static inline void mpol_get(struct mempolicy *pol)
 {
 }
 
-static inline struct mempolicy *mpol_copy(struct mempolicy *old)
+static inline struct mempolicy *mpol_dup(struct mempolicy *old)
 {
        return NULL;
 }
@@ -221,7 +256,7 @@ static inline int mpol_set_shared_policy(struct shared_policy *info,
 }
 
 static inline void mpol_shared_policy_init(struct shared_policy *info,
-               unsigned short policy, unsigned short flags, nodemask_t *nodes)
+               unsigned short mode, unsigned short flags, nodemask_t *nodes)
 {
 }