[PATCH] include/linux/nodemask.h: Use nr_node_ids instead of MAX_NUMNODES in nodemask_pr_args

[Waiman Long]

When viewing the /proc/<pid>/status file, one can see output lines like

  Cpus_allowed:	ffffffff,ffffffff,ffffffff
  Cpus_allowed_list:	0-95
  Mems_allowed:	00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000,0000000f
  Mems_allowed_list:	0-3

It looks really strange that so many bits are displayed in the
"Mems_allowed:" line.  Whereas the "Cpus_allowed:" line is perfectly
fine.

It is because the nodemask_pr_args() macro uses MAX_NUMNODES as the
number of nodes to iterate. The cpumask_pr_args() macro uses nr_cpu_ids
instead of MAX_CPUS. For nodes, there is a corresponding nr_node_ids.
So it makes sense to use nr_node_ids instead to be consistent with
"Cpus_allowed:".

With that change, the "Mems_allowed:" line becomes

  Mems_allowed:	f

Signed-off-by: Waiman Long <longman@xxxxxxxxxx>
---
 include/linux/nodemask.h | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/include/linux/nodemask.h b/include/linux/nodemask.h
index 5a30ad5..ba07661 100644
--- a/include/linux/nodemask.h
+++ b/include/linux/nodemask.h
@@ -97,6 +97,8 @@
 
 typedef struct { DECLARE_BITMAP(bits, MAX_NUMNODES); } nodemask_t;
 extern nodemask_t _unused_nodemask_arg_;
+extern int nr_node_ids;
+extern int nr_online_nodes;
 
 /**
  * nodemask_pr_args - printf args to output a nodemask
@@ -108,7 +110,7 @@
 				__nodemask_pr_bits(maskp)
 static inline unsigned int __nodemask_pr_numnodes(const nodemask_t *m)
 {
-	return m ? MAX_NUMNODES : 0;
+	return m ? nr_node_ids : 0;
 }
 static inline const unsigned long *__nodemask_pr_bits(const nodemask_t *m)
 {
@@ -444,9 +446,6 @@ static inline int next_memory_node(int nid)
 	return next_node(nid, node_states[N_MEMORY]);
 }
 
-extern int nr_node_ids;
-extern int nr_online_nodes;
-
 static inline void node_set_online(int nid)
 {
 	node_set_state(nid, N_ONLINE);
-- 
1.8.3.1