oprofile/x86: notify cpus only when daemon is running

This patch moves the cpu notifier registration from nmi_init() to
nmi_setup(). The corresponding unregistration function is now in
nmi_shutdown(). Thus, the hotplug code is only active, if the oprofile
daemon is running.

Cc: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Robert Richter <robert.richter@amd.com>

1 files changed, 3 insertions, 13 deletions

diff --git a/arch/x86/oprofile/nmi_int.c b/arch/x86/oprofile/nmi_int.c
index 7de0572b0a5e..2a086726cad1 100644
--- a/arch/x86/oprofile/nmi_int.c
+++ b/arch/x86/oprofile/nmi_int.c
@@ -504,6 +504,7 @@ static int nmi_setup(void)
                 goto fail;
 
         get_online_cpus();
+        register_cpu_notifier(&oprofile_cpu_nb);
         on_each_cpu(nmi_cpu_setup, NULL, 1);
         nmi_enabled = 1;
         put_online_cpus();
@@ -519,6 +520,7 @@ static void nmi_shutdown(void)
         struct op_msrs *msrs;
 
         get_online_cpus();
+        unregister_cpu_notifier(&oprofile_cpu_nb);
         on_each_cpu(nmi_cpu_shutdown, NULL, 1);
         nmi_enabled = 0;
         ctr_running = 0;
@@ -739,12 +741,6 @@ int __init op_nmi_init(struct oprofile_operations *ops)
                 return -ENODEV;
         }
 
-        get_online_cpus();
-        register_cpu_notifier(&oprofile_cpu_nb);
-        nmi_enabled = 0;
-        ctr_running = 0;
-        put_online_cpus();
-
         /* default values, can be overwritten by model */
         ops->create_files       = nmi_create_files;
         ops->setup              = nmi_setup;
@@ -771,14 +767,8 @@ int __init op_nmi_init(struct oprofile_operations *ops)
 
 void op_nmi_exit(void)
 {
-        if (using_nmi) {
+        if (using_nmi)
                 exit_sysfs();
-                get_online_cpus();
-                unregister_cpu_notifier(&oprofile_cpu_nb);
-                nmi_enabled = 0;
-                ctr_running = 0;
-                put_online_cpus();
-        }
         if (model->exit)
                 model->exit();
 }