ftrace-crap.patch

Subject: ftrace-crap.patch
From: Thomas Gleixner <tglx@linutronix.de>
Date: Fri, 09 Sep 2011 16:55:53 +0200

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
 kernel/trace/trace.c |   26 ++++++++++++++++++++++++--
 kernel/trace/trace.h |    1 -
 2 files changed, 24 insertions(+), 3 deletions(-)

Index: linux-stable/kernel/trace/trace.c
===================================================================
--- linux-stable.orig/kernel/trace/trace.c
+++ linux-stable/kernel/trace/trace.c
@@ -402,11 +402,13 @@ EXPORT_SYMBOL_GPL(tracing_is_on);
  */
 void trace_wake_up(void)
 {
+#ifndef CONFIG_PREEMPT_RT_FULL
 	const unsigned long delay = msecs_to_jiffies(2);
 
 	if (trace_flags & TRACE_ITER_BLOCK)
 		return;
 	schedule_delayed_work(&wakeup_work, delay);
+#endif
 }
 
 static int __init set_buf_size(char *str)
@@ -756,6 +758,12 @@ update_max_tr_single(struct trace_array 
 }
 #endif /* CONFIG_TRACER_MAX_TRACE */
 
+#ifndef CONFIG_PREEMPT_RT_FULL
+static void default_wait_pipe(struct trace_iterator *iter);
+#else
+#define default_wait_pipe	poll_wait_pipe
+#endif
+
 /**
  * register_tracer - register a tracer with the ftrace system.
  * @type - the plugin for the tracer
@@ -3365,6 +3373,7 @@ static int tracing_release_pipe(struct i
 	return 0;
 }
 
+#ifndef CONFIG_PREEMPT_RT_FULL
 static unsigned int
 tracing_poll_pipe(struct file *filp, poll_table *poll_table)
 {
@@ -3386,8 +3395,7 @@ tracing_poll_pipe(struct file *filp, pol
 	}
 }
 
-
-void default_wait_pipe(struct trace_iterator *iter)
+static void default_wait_pipe(struct trace_iterator *iter)
 {
 	DEFINE_WAIT(wait);
 
@@ -3398,6 +3406,20 @@ void default_wait_pipe(struct trace_iter
 
 	finish_wait(&trace_wait, &wait);
 }
+#else
+static unsigned int
+tracing_poll_pipe(struct file *filp, poll_table *poll_table)
+{
+	struct trace_iterator *iter = filp->private_data;
+
+	if ((trace_flags & TRACE_ITER_BLOCK) || !trace_empty(iter))
+		return POLLIN | POLLRDNORM;
+	poll_wait_pipe(iter);
+	if (!trace_empty(iter))
+		return POLLIN | POLLRDNORM;
+	return 0;
+}
+#endif
 
 /*
  * This is a make-shift waitqueue.
Index: linux-stable/kernel/trace/trace.h
===================================================================
--- linux-stable.orig/kernel/trace/trace.h
+++ linux-stable/kernel/trace/trace.h
@@ -367,7 +367,6 @@ void trace_init_global_iter(struct trace
 
 void tracing_iter_reset(struct trace_iterator *iter, int cpu);
 
-void default_wait_pipe(struct trace_iterator *iter);
 void poll_wait_pipe(struct trace_iterator *iter);
 
 void ftrace(struct trace_array *tr,