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>

diff --git a/arch/x86/oprofile/nmi_int.c b/arch/x86/oprofile/nmi_int.c
index 7de0572..2a08672 100644 (file)
--- 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();
 }