tracing: Move tracing_max_latency into trace_array

In preparation for letting the latency tracers be used by instances,
remove the global tracing_max_latency variable and add a max_latency
field to the trace_array that the latency tracers will now use.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
diff --git a/kernel/trace/trace_irqsoff.c b/kernel/trace/trace_irqsoff.c
index b5cb047..40aa300 100644
--- a/kernel/trace/trace_irqsoff.c
+++ b/kernel/trace/trace_irqsoff.c
@@ -170,7 +170,7 @@
 	for_each_possible_cpu(cpu)
 		per_cpu(tracing_cpu, cpu) = 0;
 
-	tracing_max_latency = 0;
+	tr->max_latency = 0;
 	tracing_reset_online_cpus(&irqsoff_trace->trace_buffer);
 
 	return start_irqsoff_tracer(irqsoff_trace, set);
@@ -297,13 +297,13 @@
 /*
  * Should this new latency be reported/recorded?
  */
-static int report_latency(cycle_t delta)
+static int report_latency(struct trace_array *tr, cycle_t delta)
 {
 	if (tracing_thresh) {
 		if (delta < tracing_thresh)
 			return 0;
 	} else {
-		if (delta <= tracing_max_latency)
+		if (delta <= tr->max_latency)
 			return 0;
 	}
 	return 1;
@@ -327,13 +327,13 @@
 
 	pc = preempt_count();
 
-	if (!report_latency(delta))
+	if (!report_latency(tr, delta))
 		goto out;
 
 	raw_spin_lock_irqsave(&max_trace_lock, flags);
 
 	/* check if we are still the max latency */
-	if (!report_latency(delta))
+	if (!report_latency(tr, delta))
 		goto out_unlock;
 
 	__trace_function(tr, CALLER_ADDR0, parent_ip, flags, pc);
@@ -346,7 +346,7 @@
 	data->critical_end = parent_ip;
 
 	if (likely(!is_tracing_stopped())) {
-		tracing_max_latency = delta;
+		tr->max_latency = delta;
 		update_max_tr_single(tr, current, cpu);
 	}
 
@@ -605,7 +605,7 @@
 	set_tracer_flag(tr, TRACE_ITER_OVERWRITE, 1);
 	set_tracer_flag(tr, TRACE_ITER_LATENCY_FMT, 1);
 
-	tracing_max_latency = 0;
+	tr->max_latency = 0;
 	irqsoff_trace = tr;
 	/* make sure that the tracer is visible */
 	smp_wmb();