diff --git a/arch/x86/oprofile/nmi_int.c b/arch/x86/oprofile/nmi_int.c
index f6b48f6c5951..cfe4faabb0f6 100644
--- a/arch/x86/oprofile/nmi_int.c
+++ b/arch/x86/oprofile/nmi_int.c
@@ -568,8 +568,13 @@ static int __init init_sysfs(void)
 	int error;
 
 	error = sysdev_class_register(&oprofile_sysclass);
-	if (!error)
-		error = sysdev_register(&device_oprofile);
+	if (error)
+		return error;
+
+	error = sysdev_register(&device_oprofile);
+	if (error)
+		sysdev_class_unregister(&oprofile_sysclass);
+
 	return error;
 }
 
@@ -580,8 +585,10 @@ static void exit_sysfs(void)
 }
 
 #else
-#define init_sysfs() do { } while (0)
-#define exit_sysfs() do { } while (0)
+
+static inline int  init_sysfs(void) { return 0; }
+static inline void exit_sysfs(void) { }
+
 #endif /* CONFIG_PM */
 
 static int __init p4_init(char **cpu_type)
@@ -695,6 +702,8 @@ int __init op_nmi_init(struct oprofile_operations *ops)
 	char *cpu_type = NULL;
 	int ret = 0;
 
+	using_nmi = 0;
+
 	if (!cpu_has_apic)
 		return -ENODEV;
 
@@ -774,7 +783,10 @@ int __init op_nmi_init(struct oprofile_operations *ops)
 
 	mux_init(ops);
 
-	init_sysfs();
+	ret = init_sysfs();
+	if (ret)
+		return ret;
+
 	using_nmi = 1;
 	printk(KERN_INFO "oprofile: using NMI interrupt.\n");
 	return 0;
diff --git a/drivers/oprofile/buffer_sync.c b/drivers/oprofile/buffer_sync.c
index a9352b2c7ac4..b7e755f4178a 100644
--- a/drivers/oprofile/buffer_sync.c
+++ b/drivers/oprofile/buffer_sync.c
@@ -141,16 +141,6 @@ static struct notifier_block module_load_nb = {
 	.notifier_call = module_load_notify,
 };
 
-
-static void end_sync(void)
-{
-	end_cpu_work();
-	/* make sure we don't leak task structs */
-	process_task_mortuary();
-	process_task_mortuary();
-}
-
-
 int sync_start(void)
 {
 	int err;
@@ -158,7 +148,7 @@ int sync_start(void)
 	if (!zalloc_cpumask_var(&marked_cpus, GFP_KERNEL))
 		return -ENOMEM;
 
-	start_cpu_work();
+	mutex_lock(&buffer_mutex);
 
 	err = task_handoff_register(&task_free_nb);
 	if (err)
@@ -173,7 +163,10 @@ int sync_start(void)
 	if (err)
 		goto out4;
 
+	start_cpu_work();
+
 out:
+	mutex_unlock(&buffer_mutex);
 	return err;
 out4:
 	profile_event_unregister(PROFILE_MUNMAP, &munmap_nb);
@@ -182,7 +175,6 @@ int sync_start(void)
 out2:
 	task_handoff_unregister(&task_free_nb);
 out1:
-	end_sync();
 	free_cpumask_var(marked_cpus);
 	goto out;
 }
@@ -190,11 +182,20 @@ int sync_start(void)
 
 void sync_stop(void)
 {
+	/* flush buffers */
+	mutex_lock(&buffer_mutex);
+	end_cpu_work();
 	unregister_module_notifier(&module_load_nb);
 	profile_event_unregister(PROFILE_MUNMAP, &munmap_nb);
 	profile_event_unregister(PROFILE_TASK_EXIT, &task_exit_nb);
 	task_handoff_unregister(&task_free_nb);
-	end_sync();
+	mutex_unlock(&buffer_mutex);
+	flush_scheduled_work();
+
+	/* make sure we don't leak task structs */
+	process_task_mortuary();
+	process_task_mortuary();
+
 	free_cpumask_var(marked_cpus);
 }
 
diff --git a/drivers/oprofile/cpu_buffer.c b/drivers/oprofile/cpu_buffer.c
index 219f79e2210a..f179ac2ea801 100644
--- a/drivers/oprofile/cpu_buffer.c
+++ b/drivers/oprofile/cpu_buffer.c
@@ -120,8 +120,6 @@ void end_cpu_work(void)
 
 		cancel_delayed_work(&b->work);
 	}
-
-	flush_scheduled_work();
 }
 
 /*