[PATCH] VM: add page_state info to per-node meminfo

Add page_state info to the per-node meminfo file in sysfs.  This is mostly
just for informational purposes.

The lack of this information was brought up recently during a discussion
regarding pagecache clearing, and I put this patch together to test out one
of the suggestions.

It seems like interesting info to have, so I'm submitting the patch.

Signed-off-by: Martin Hicks <mort@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index d157dae..b06a963 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -1130,19 +1130,20 @@
 DEFINE_PER_CPU(long, nr_pagecache_local) = 0;
 #endif
 
-void __get_page_state(struct page_state *ret, int nr)
+void __get_page_state(struct page_state *ret, int nr, cpumask_t *cpumask)
 {
 	int cpu = 0;
 
 	memset(ret, 0, sizeof(*ret));
+	cpus_and(*cpumask, *cpumask, cpu_online_map);
 
-	cpu = first_cpu(cpu_online_map);
+	cpu = first_cpu(*cpumask);
 	while (cpu < NR_CPUS) {
 		unsigned long *in, *out, off;
 
 		in = (unsigned long *)&per_cpu(page_states, cpu);
 
-		cpu = next_cpu(cpu, cpu_online_map);
+		cpu = next_cpu(cpu, *cpumask);
 
 		if (cpu < NR_CPUS)
 			prefetch(&per_cpu(page_states, cpu));
@@ -1153,19 +1154,33 @@
 	}
 }
 
-void get_page_state(struct page_state *ret)
+void get_page_state_node(struct page_state *ret, int node)
 {
 	int nr;
+	cpumask_t mask = node_to_cpumask(node);
 
 	nr = offsetof(struct page_state, GET_PAGE_STATE_LAST);
 	nr /= sizeof(unsigned long);
 
-	__get_page_state(ret, nr + 1);
+	__get_page_state(ret, nr+1, &mask);
+}
+
+void get_page_state(struct page_state *ret)
+{
+	int nr;
+	cpumask_t mask = CPU_MASK_ALL;
+
+	nr = offsetof(struct page_state, GET_PAGE_STATE_LAST);
+	nr /= sizeof(unsigned long);
+
+	__get_page_state(ret, nr + 1, &mask);
 }
 
 void get_full_page_state(struct page_state *ret)
 {
-	__get_page_state(ret, sizeof(*ret) / sizeof(unsigned long));
+	cpumask_t mask = CPU_MASK_ALL;
+
+	__get_page_state(ret, sizeof(*ret) / sizeof(unsigned long), &mask);
 }
 
 unsigned long __read_page_state(unsigned long offset)