[GIT PULL] tracing: Three more clean up patches for 4.4

[Steven Rostedt]

Linus,

This contains three more clean up patches.

One patch is needed to make tracing work without debugfs now that tracing
uses its own tracefs.

The second is removing an unused variable.

The third is fixing a warning about unused variables when MAX_TRACER is
not configured. Note, this warning shows up in gcc 6.0, but does not show
up in gcc 4.9, as it seems that gcc does not complain about constants
not being used.


Please pull the latest trace-v4.4-2 tree, which can be found at:


  git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace.git
trace-v4.4-2

Tag SHA1: 018dd5568dd784f3c94e7a8d27c7b73cbc2f23d0
Head SHA1: e428abbbf616cd8fdd1162e4a624ad1d47b47544


Chen Gang (1):
      tracing: #ifdef out uses of max trace when CONFIG_TRACER_MAX_TRACE is not set

Dmitry Safonov (1):
      tracing: Remove unused ftrace_cpu_disabled per cpu variable

Jiaxing Wang (1):
      tracing: Make tracing work when debugfs is not configured in

----
 kernel/trace/trace.c                 | 16 +++++++++-------
 kernel/trace/trace.h                 |  1 -
 kernel/trace/trace_functions_graph.c |  6 ------
 3 files changed, 9 insertions(+), 14 deletions(-)
---------------------------
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 2198a630ef58..87fb9801bd9e 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -100,8 +100,6 @@ static DEFINE_PER_CPU(bool, trace_cmdline_save);
  */
 static int tracing_disabled = 1;
 
-DEFINE_PER_CPU(int, ftrace_cpu_disabled);
-
 cpumask_var_t __read_mostly	tracing_buffer_mask;
 
 /*
@@ -1775,10 +1773,6 @@ trace_function(struct trace_array *tr,
 	struct ring_buffer_event *event;
 	struct ftrace_entry *entry;
 
-	/* If we are reading the ring buffer, don't trace */
-	if (unlikely(__this_cpu_read(ftrace_cpu_disabled)))
-		return;
-
 	event = trace_buffer_lock_reserve(buffer, TRACE_FN, sizeof(*entry),
 					  flags, pc);
 	if (!event)
@@ -4554,6 +4548,8 @@ out:
 	return ret;
 }
 
+#ifdef CONFIG_TRACER_MAX_TRACE
+
 static ssize_t
 tracing_max_lat_read(struct file *filp, char __user *ubuf,
 		     size_t cnt, loff_t *ppos)
@@ -4568,6 +4564,8 @@ tracing_max_lat_write(struct file *filp, const char __user *ubuf,
 	return tracing_nsecs_write(filp->private_data, ubuf, cnt, ppos);
 }
 
+#endif
+
 static int tracing_open_pipe(struct inode *inode, struct file *filp)
 {
 	struct trace_array *tr = inode->i_private;
@@ -5469,12 +5467,14 @@ static const struct file_operations tracing_thresh_fops = {
 	.llseek		= generic_file_llseek,
 };
 
+#ifdef CONFIG_TRACER_MAX_TRACE
 static const struct file_operations tracing_max_lat_fops = {
 	.open		= tracing_open_generic,
 	.read		= tracing_max_lat_read,
 	.write		= tracing_max_lat_write,
 	.llseek		= generic_file_llseek,
 };
+#endif
 
 static const struct file_operations set_tracer_fops = {
 	.open		= tracing_open_generic,
@@ -6847,7 +6847,9 @@ struct dentry *tracing_init_dentry(void)
 	if (tr->dir)
 		return NULL;
 
-	if (WARN_ON(!debugfs_initialized()))
+	if (WARN_ON(!tracefs_initialized()) ||
+		(IS_ENABLED(CONFIG_DEBUG_FS) &&
+		 WARN_ON(!debugfs_initialized())))
 		return ERR_PTR(-ENODEV);
 
 	/*
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index dd7620802e72..919d9d07686f 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -667,7 +667,6 @@ extern int DYN_FTRACE_TEST_NAME2(void);
 
 extern bool ring_buffer_expanded;
 extern bool tracing_selftest_disabled;
-DECLARE_PER_CPU(int, ftrace_cpu_disabled);
 
 #ifdef CONFIG_FTRACE_STARTUP_TEST
 extern int trace_selftest_startup_function(struct tracer *trace,
diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c
index 92382af7a213..a663cbb84107 100644
--- a/kernel/trace/trace_functions_graph.c
+++ b/kernel/trace/trace_functions_graph.c
@@ -288,9 +288,6 @@ int __trace_graph_entry(struct trace_array *tr,
 	struct ring_buffer *buffer = tr->trace_buffer.buffer;
 	struct ftrace_graph_ent_entry *entry;
 
-	if (unlikely(__this_cpu_read(ftrace_cpu_disabled)))
-		return 0;
-
 	event = trace_buffer_lock_reserve(buffer, TRACE_GRAPH_ENT,
 					  sizeof(*entry), flags, pc);
 	if (!event)
@@ -403,9 +400,6 @@ void __trace_graph_return(struct trace_array *tr,
 	struct ring_buffer *buffer = tr->trace_buffer.buffer;
 	struct ftrace_graph_ret_entry *entry;
 
-	if (unlikely(__this_cpu_read(ftrace_cpu_disabled)))
-		return;
-
 	event = trace_buffer_lock_reserve(buffer, TRACE_GRAPH_RET,
 					  sizeof(*entry), flags, pc);
 	if (!event)
--
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