mm/vmalloc: make show_numa_info() aware of hugepage mappings

show_numa_info() can be slightly faster, by skipping over hugepages
directly.

Link: https://lkml.kernel.org/r/20211001172725.105824-1-eric.dumazet@gmail.comSigned-off-by: Eric Dumazet <edumazet@google.com>
Cc: Uladzislau Rezki (Sony) <urezki@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/vmalloc.c

@@ -3864,6 +3864,7 @@ static void show_numa_info(struct seq_file *m, struct vm_struct *v)
 {
 	if (IS_ENABLED(CONFIG_NUMA)) {
 		unsigned int nr, *counters = m->private;
+		unsigned int step = 1U << vm_area_page_order(v);
 
 		if (!counters)
 			return;
@@ -3875,9 +3876,8 @@ static void show_numa_info(struct seq_file *m, struct vm_struct *v)
 
 		memset(counters, 0, nr_node_ids * sizeof(unsigned int));
 
-		for (nr = 0; nr < v->nr_pages; nr++)
-			counters[page_to_nid(v->pages[nr])]++;
-
+		for (nr = 0; nr < v->nr_pages; nr += step)
+			counters[page_to_nid(v->pages[nr])] += step;
 		for_each_node_state(nr, N_HIGH_MEMORY)
 			if (counters[nr])
 				seq_printf(m, " N%u=%u", nr, counters[nr]);