mm/vmalloc.c: check VM_UNINITIALIZED flag in s_show instead of show_numa_info

We should check the VM_UNITIALIZED flag in s_show().  If this flag is
set, that said, the vm_struct is not fully initialized.  So it is
unnecessary to try to show the information contained in vm_struct.

We checked this flag in show_numa_info(), but I think it's better to
check it earlier.

Signed-off-by: Zhang Yanfei <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

Author: Zhang Yanfei

mm/vmalloc.c

@@ -2569,11 +2569,6 @@ static void show_numa_info(struct seq_file *m, struct vm_struct *v)
 		if (!counters)
 			return;
 
-		/* Pair with smp_wmb() in clear_vm_uninitialized_flag() */
-		smp_rmb();
-		if (v->flags & VM_UNINITIALIZED)
-			return;
-
 		memset(counters, 0, nr_node_ids * sizeof(unsigned int));
 
 		for (nr = 0; nr < v->nr_pages; nr++)
@@ -2602,6 +2597,11 @@ static int s_show(struct seq_file *m, void *p)
 
 	v = va->vm;
 
+	/* Pair with smp_wmb() in clear_vm_uninitialized_flag() */
+	smp_rmb();
+	if (v->flags & VM_UNINITIALIZED)
+		return 0;
+
 	seq_printf(m, "0x%pK-0x%pK %7ld",
 		v->addr, v->addr + v->size, v->size);