Add brief discussion of mode flags.

man2/mbind.2

@@ -120,6 +120,30 @@ require the caller to specify via the
 argument,
 the node or nodes to which the mode applies.
 
+The
+.I mode
+argument may also include an optional
+.IR "mode flag ".
+The supported
+.I "mode flags"
+are:
+.TP
+.BR MPOL_F_STATIC_NODES " (since Linux-2.6.26)"
+A non-empty
+.I nodemask
+specifies physical node ids.
+Linux does will not remap the
+.I nodemask
+when the task moves to a different cpuset context,
+nor when the set of nodes allowed by the task's
+current cpuset context changes.
+.TP
+.BR MPOL_F_RELATIVE_NODES " (since Linux-2.6.26)"
+A non-empty
+.I nodemask
+specifies node ids that are relative to the set of
+node ids allowed  by the task's current cpuset.
+.PP
 .I nodemask
 points to a bitmask of nodes containing up to
 .I maxnode
@@ -142,7 +166,10 @@ argument is ignored.
 Where a
 .I nodemask
 is required, it must contain at least one node that is on-line,
-allowed by the process's current cpuset context,
+allowed by the process's current cpuset context
+[unless the
+.B MPOL_F_STATIC_NODES
+mode flag is specified],
 and contains memory.
 
 The
@@ -319,6 +346,12 @@ Or, none of the node IDs specified by
 .I nodemask
 are on-line and allowed by the process's current cpuset context,
 or none of the specified nodes contain memory.
+Or, the
+.I mode
+argument specified both
+.B MPOL_F_STATIC_NODES
+and
+.BR MPOL_F_RELATIVE_NODES .
 .TP
 .B EIO
 .B MPOL_MF_STRICT