x86: Do not free zero sized per cpu areas

[safe/jmp/linux-2.6] / kernel / perf_event.c

diff --git a/kernel/perf_event.c b/kernel/perf_event.c
index c502b18..574ee58 100644 (file)
--- a/kernel/perf_event.c
+++ b/kernel/perf_event.c
@@ -2786,10 +2786,12 @@ __weak struct perf_callchain_entry *perf_callchain(struct pt_regs *regs)
        return NULL;
 }
 
+#ifdef CONFIG_EVENT_TRACING
 __weak
 void perf_arch_fetch_caller_regs(struct pt_regs *regs, unsigned long ip, int skip)
 {
 }
+#endif
 
 /*
  * Output
@@ -5368,12 +5370,22 @@ int perf_event_init_task(struct task_struct *child)
        return ret;
 }
 
+static void __init perf_event_init_all_cpus(void)
+{
+       int cpu;
+       struct perf_cpu_context *cpuctx;
+
+       for_each_possible_cpu(cpu) {
+               cpuctx = &per_cpu(perf_cpu_context, cpu);
+               __perf_event_init_context(&cpuctx->ctx, NULL);
+       }
+}
+
 static void __cpuinit perf_event_init_cpu(int cpu)
 {
        struct perf_cpu_context *cpuctx;
 
        cpuctx = &per_cpu(perf_cpu_context, cpu);
-       __perf_event_init_context(&cpuctx->ctx, NULL);
 
        spin_lock(&perf_resource_lock);
        cpuctx->max_pertask = perf_max_events - perf_reserved_percpu;
@@ -5439,6 +5451,7 @@ static struct notifier_block __cpuinitdata perf_cpu_nb = {
 
 void __init perf_event_init(void)
 {
+       perf_event_init_all_cpus();
        perf_cpu_notify(&perf_cpu_nb, (unsigned long)CPU_UP_PREPARE,
                        (void *)(long)smp_processor_id());
        perf_cpu_notify(&perf_cpu_nb, (unsigned long)CPU_ONLINE,