include/linux/nodemask.h: use nr_node_ids (not MAX_NUMNODES) in __nodemask_pr_numnodes()

Waiman-Long · sfrothwell · commit 4fb8e5b89bcb · 2019-02-09T15:47:19.000+11:00
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 The "Mems_allowed" line uses the "%*pb" format string while the "Mems_allowed_list" line uses the "%*pbl" format string together with the nodemask_pr_args() macro. The "Mems_allowed" looks insane compared with the others. 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 sane again. Mems_allowed: f There are currently 10 call sites of nodemask_pr_args() in the kernel. Of them, only cpuset_task_status_allowed() in kernel/cgroup/cpuset.c uses the "%*pb" format string that will be affected by this change. That cpuset function is called by proc_pid_status() only. Link: http://lkml.kernel.org/r/1545405631-6808-1-git-send-email-longman@redhat.com Signed-off-by: Waiman Long <longman@redhat.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Oscar Salvador <osalvador@suse.de> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
diff --git a/include/linux/nodemask.h b/include/linux/nodemask.h
@@ -98,6 +98,14 @@
 typedef struct { DECLARE_BITMAP(bits, MAX_NUMNODES); } nodemask_t;
 extern nodemask_t _unused_nodemask_arg_;
 
+#if MAX_NUMNODES > 1
+extern int nr_node_ids;
+extern int nr_online_nodes;
+#else
+#define nr_node_ids	1
+#define nr_online_nodes	1
+#endif
+
 /**
  * nodemask_pr_args - printf args to output a nodemask
  * @maskp: nodemask to be printed
@@ -108,7 +116,7 @@ extern nodemask_t _unused_nodemask_arg_;
 				__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 +452,6 @@ 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);
@@ -485,8 +490,6 @@ static inline int num_node_state(enum node_states state)
 #define first_online_node	0
 #define first_memory_node	0
 #define next_online_node(nid)	(MAX_NUMNODES)
-#define nr_node_ids		1
-#define nr_online_nodes		1
 
 #define node_set_online(node)	   node_set_state((node), N_ONLINE)
 #define node_set_offline(node)	   node_clear_state((node), N_ONLINE)
