1 files changed, 9 insertions, 15 deletions

diff --git a/mm/page_cgroup.c b/mm/page_cgroup.c
index 11a8a10..f22b4eb 100644
--- a/mm/page_cgroup.c
+++ b/mm/page_cgroup.c
@@ -83,12 +83,12 @@ void __init page_cgroup_init_flatmem(void)
 			goto fail;
 	}
 	printk(KERN_INFO "allocated %ld bytes of page_cgroup\n", total_usage);
-	printk(KERN_INFO "please try cgroup_disable=memory option if you"
-	" don't want\n");
+	printk(KERN_INFO "please try 'cgroup_disable=memory' option if you"
+	" don't want memory cgroups\n");
 	return;
 fail:
-	printk(KERN_CRIT "allocation of page_cgroup was failed.\n");
-	printk(KERN_CRIT "please try cgroup_disable=memory boot option\n");
+	printk(KERN_CRIT "allocation of page_cgroup failed.\n");
+	printk(KERN_CRIT "please try 'cgroup_disable=memory' boot option\n");
 	panic("Out of memory");
 }
 
@@ -99,6 +99,8 @@ struct page_cgroup *lookup_page_cgroup(struct page *page)
 	unsigned long pfn = page_to_pfn(page);
 	struct mem_section *section = __pfn_to_section(pfn);
 
+	if (!section->page_cgroup)
+		return NULL;
 	return section->page_cgroup + pfn;
 }
 
@@ -252,14 +254,14 @@ void __init page_cgroup_init(void)
 		fail = init_section_page_cgroup(pfn);
 	}
 	if (fail) {
-		printk(KERN_CRIT "try cgroup_disable=memory boot option\n");
+		printk(KERN_CRIT "try 'cgroup_disable=memory' boot option\n");
 		panic("Out of memory");
 	} else {
 		hotplug_memory_notifier(page_cgroup_callback, 0);
 	}
 	printk(KERN_INFO "allocated %ld bytes of page_cgroup\n", total_usage);
-	printk(KERN_INFO "please try cgroup_disable=memory option if you don't"
-	" want\n");
+	printk(KERN_INFO "please try 'cgroup_disable=memory' option if you don't"
+	" want memory cgroups\n");
 }
 
 void __meminit pgdat_page_cgroup_init(struct pglist_data *pgdat)
@@ -309,8 +311,6 @@ static int swap_cgroup_prepare(int type)
 	struct swap_cgroup_ctrl *ctrl;
 	unsigned long idx, max;
 
-	if (!do_swap_account)
-		return 0;
 	ctrl = &swap_cgroup_ctrl[type];
 
 	for (idx = 0; idx < ctrl->length; idx++) {
@@ -347,9 +347,6 @@ unsigned short swap_cgroup_record(swp_entry_t ent, unsigned short id)
 	struct swap_cgroup *sc;
 	unsigned short old;
 
-	if (!do_swap_account)
-		return 0;
-
 	ctrl = &swap_cgroup_ctrl[type];
 
 	mappage = ctrl->map[idx];
@@ -378,9 +375,6 @@ unsigned short lookup_swap_cgroup(swp_entry_t ent)
 	struct swap_cgroup *sc;
 	unsigned short ret;
 
-	if (!do_swap_account)
-		return 0;
-
 	ctrl = &swap_cgroup_ctrl[type];
 	mappage = ctrl->map[idx];
 	sc = page_address(mappage);