ftrace: build fix

no need to backmerge, only affects ftrace-enabled kernels. (which is
not the default)

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 6974b212e93886d6e689e7dc5465fb65f9d47086..958c4d77a67b8e1c19291d1eae6a854d4c2a14e1 100644 (file)
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -1965,7 +1965,9 @@ tracing_read_pipe(struct file *filp, char __user *ubuf,
        static cpumask_t mask;
        static int start;
        unsigned long flags;
+#ifdef CONFIG_FTRACE
        int ftrace_save;
+#endif
        int read = 0;
        int cpu;
        int len;
@@ -2044,8 +2046,10 @@ tracing_read_pipe(struct file *filp, char __user *ubuf,
 
        cpus_clear(mask);
        local_irq_save(flags);
+#ifdef CONFIG_FTRACE
        ftrace_save = ftrace_enabled;
        ftrace_enabled = 0;
+#endif
        smp_wmb();
        for_each_possible_cpu(cpu) {
                data = iter->tr->data[cpu];
@@ -2087,7 +2091,9 @@ tracing_read_pipe(struct file *filp, char __user *ubuf,
                data = iter->tr->data[cpu];
                atomic_dec(&data->disabled);
        }
+#ifdef CONFIG_FTRACE
        ftrace_enabled = ftrace_save;
+#endif
        local_irq_restore(flags);
 
        /* Now copy what we have to the user */