2 files changed, 7 insertions, 5 deletions

diff --git a/include/uapi/linux/mempolicy.h b/include/uapi/linux/mempolicy.h
index 3e835c9d847b..d23dca8367cc 100644
--- a/include/uapi/linux/mempolicy.h
+++ b/include/uapi/linux/mempolicy.h
@@ -21,6 +21,7 @@ enum {
         MPOL_BIND,
         MPOL_INTERLEAVE,
         MPOL_LOCAL,
+        MPOL_NOOP,              /* retain existing policy for range */
         MPOL_MAX,       /* always last member of enum */
 };
 
diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index 54bd3e5ed776..c21e91477c4f 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -251,10 +251,10 @@ static struct mempolicy *mpol_new(unsigned short mode, unsigned short flags,
         pr_debug("setting mode %d flags %d nodes[0] %lx\n",
                  mode, flags, nodes ? nodes_addr(*nodes)[0] : -1);
 
-        if (mode == MPOL_DEFAULT) {
+        if (mode == MPOL_DEFAULT || mode == MPOL_NOOP) {
                 if (nodes && !nodes_empty(*nodes))
                         return ERR_PTR(-EINVAL);
-                return NULL;    /* simply delete any existing policy */
+                return NULL;
         }
         VM_BUG_ON(!nodes);
 
@@ -1147,7 +1147,7 @@ static long do_mbind(unsigned long start, unsigned long len,
         if (start & ~PAGE_MASK)
                 return -EINVAL;
 
-        if (mode == MPOL_DEFAULT)
+        if (mode == MPOL_DEFAULT || mode == MPOL_NOOP)
                 flags &= ~MPOL_MF_STRICT;
 
         len = (len + PAGE_SIZE - 1) & PAGE_MASK;
@@ -2409,7 +2409,8 @@ static const char * const policy_modes[] =
         [MPOL_PREFERRED]  = "prefer",
         [MPOL_BIND]       = "bind",
         [MPOL_INTERLEAVE] = "interleave",
-        [MPOL_LOCAL]      = "local"
+        [MPOL_LOCAL]      = "local",
+        [MPOL_NOOP]       = "noop",     /* should not actually be used */
 };
 
 
@@ -2460,7 +2461,7 @@ int mpol_parse_str(char *str, struct mempolicy **mpol, int no_context)
                         break;
                 }
         }
-        if (mode >= MPOL_MAX)
+        if (mode >= MPOL_MAX || mode == MPOL_NOOP)
                 goto out;
 
         switch (mode) {