1 files changed, 39 insertions, 4 deletions

diff --git a/arch/x86/oprofile/nmi_int.c b/arch/x86/oprofile/nmi_int.c
index 3f90289410e..8a5f1614a3d 100644
--- a/arch/x86/oprofile/nmi_int.c
+++ b/arch/x86/oprofile/nmi_int.c
@@ -15,6 +15,7 @@
 #include <linux/slab.h>
 #include <linux/moduleparam.h>
 #include <linux/kdebug.h>
+#include <linux/cpu.h>
 #include <asm/nmi.h>
 #include <asm/msr.h>
 #include <asm/apic.h>
@@ -28,23 +29,48 @@ static DEFINE_PER_CPU(unsigned long, saved_lvtpc);
 
 static int nmi_start(void);
 static void nmi_stop(void);
+static void nmi_cpu_start(void *dummy);
+static void nmi_cpu_stop(void *dummy);
 
 /* 0 == registered but off, 1 == registered and on */
 static int nmi_enabled = 0;
 
+#ifdef CONFIG_SMP
+static int oprofile_cpu_notifier(struct notifier_block *b, unsigned long action,
+                                 void *data)
+{
+        int cpu = (unsigned long)data;
+        switch (action) {
+        case CPU_DOWN_FAILED:
+        case CPU_ONLINE:
+                smp_call_function_single(cpu, nmi_cpu_start, NULL, 0);
+                break;
+        case CPU_DOWN_PREPARE:
+                smp_call_function_single(cpu, nmi_cpu_stop, NULL, 1);
+                break;
+        }
+        return NOTIFY_DONE;
+}
+
+static struct notifier_block oprofile_cpu_nb = {
+        .notifier_call = oprofile_cpu_notifier
+};
+#endif
+
 #ifdef CONFIG_PM
 
 static int nmi_suspend(struct sys_device *dev, pm_message_t state)
 {
+        /* Only one CPU left, just stop that one */
         if (nmi_enabled == 1)
-                nmi_stop();
+                nmi_cpu_stop(NULL);
         return 0;
 }
 
 static int nmi_resume(struct sys_device *dev)
 {
         if (nmi_enabled == 1)
-                nmi_start();
+                nmi_cpu_start(NULL);
         return 0;
 }
 
@@ -269,10 +295,12 @@ static void nmi_cpu_shutdown(void *dummy)
 
 static void nmi_shutdown(void)
 {
-        struct op_msrs *msrs = &get_cpu_var(cpu_msrs);
+        struct op_msrs *msrs;
+
         nmi_enabled = 0;
         on_each_cpu(nmi_cpu_shutdown, NULL, 1);
         unregister_die_notifier(&profile_exceptions_nb);
+        msrs = &get_cpu_var(cpu_msrs);
         model->shutdown(msrs);
         free_msrs();
         put_cpu_var(cpu_msrs);
@@ -463,6 +491,9 @@ int __init op_nmi_init(struct oprofile_operations *ops)
         }
 
         init_sysfs();
+#ifdef CONFIG_SMP
+        register_cpu_notifier(&oprofile_cpu_nb);
+#endif
         using_nmi = 1;
         ops->create_files = nmi_create_files;
         ops->setup = nmi_setup;
@@ -476,6 +507,10 @@ int __init op_nmi_init(struct oprofile_operations *ops)
 
 void op_nmi_exit(void)
 {
-        if (using_nmi)
+        if (using_nmi) {
                 exit_sysfs();
+#ifdef CONFIG_SMP
+                unregister_cpu_notifier(&oprofile_cpu_nb);
+#endif
+        }
 }