Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1436047

[for-next][PATCH 12/12] tracing/function_graph: Fix filters for function_graph threshold

Show all headers | View raw

From: Joel Fernandes <agnel.joel@gmail.com>

Function graph tracer currently ignores filters if tracing_thresh is set.
For example, even if set_ftrace_pid is set, then its ignored if tracing_thresh
set, resulting in all processes being traced.

To fix this, we reuse the same entry function as when tracing_thresh is not
set and do everything as in the regular case except for writing the function entry
to the ring buffer.

Link: http://lkml.kernel.org/r/1466228694-2677-1-git-send-email-agnel.joel@gmail.com

Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Signed-off-by: Joel Fernandes <agnel.joel@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
---
 kernel/trace/trace_functions_graph.c | 17 ++++++++---------
 1 file changed, 8 insertions(+), 9 deletions(-)

diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c
index 67cce7896aeb..7363ccf79512 100644
--- a/kernel/trace/trace_functions_graph.c
+++ b/kernel/trace/trace_functions_graph.c
@@ -338,6 +338,13 @@ int trace_graph_entry(struct ftrace_graph_ent *trace)
 	if (ftrace_graph_notrace_addr(trace->func))
 		return 1;
 
+	/*
+	 * Stop here if tracing_threshold is set. We only write function return
+	 * events to the ring buffer.
+	 */
+	if (tracing_thresh)
+		return 1;
+
 	local_irq_save(flags);
 	cpu = raw_smp_processor_id();
 	data = per_cpu_ptr(tr->trace_buffer.data, cpu);
@@ -355,14 +362,6 @@ int trace_graph_entry(struct ftrace_graph_ent *trace)
 	return ret;
 }
 
-static int trace_graph_thresh_entry(struct ftrace_graph_ent *trace)
-{
-	if (tracing_thresh)
-		return 1;
-	else
-		return trace_graph_entry(trace);
-}
-
 static void
 __trace_graph_function(struct trace_array *tr,
 		unsigned long ip, unsigned long flags, int pc)
@@ -457,7 +456,7 @@ static int graph_trace_init(struct trace_array *tr)
 	set_graph_array(tr);
 	if (tracing_thresh)
 		ret = register_ftrace_graph(&trace_graph_thresh_return,
-					    &trace_graph_thresh_entry);
+					    &trace_graph_entry);
 	else
 		ret = register_ftrace_graph(&trace_graph_return,
 					    &trace_graph_entry);
-- 
2.8.1

Back to linux.kernel | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread

Thread

[for-next][PATCH 00/12] tracing: Updates for 4.8 Steven Rostedt <rostedt@goodmis.org> - 2016-07-03 22:40 +0200
  [for-next][PATCH 09/12] tracing: Show the preempt count of when the event was called Steven Rostedt <rostedt@goodmis.org> - 2016-07-03 22:40 +0200
  [for-next][PATCH 01/12] tracing: Make the pid filtering helper functions global Steven Rostedt <rostedt@goodmis.org> - 2016-07-03 22:40 +0200
  [for-next][PATCH 11/12] tracing: Skip more functions when doing stack tracing of events Steven Rostedt <rostedt@goodmis.org> - 2016-07-03 22:40 +0200
  [for-next][PATCH 04/12] tracing: Move pid_list write processing into its own function Steven Rostedt <rostedt@goodmis.org> - 2016-07-03 22:40 +0200
  [for-next][PATCH 12/12] tracing/function_graph: Fix filters for function_graph threshold Steven Rostedt <rostedt@goodmis.org> - 2016-07-03 22:40 +0200
  [for-next][PATCH 06/12] tracing: expose current->comm to [ku]probe events Steven Rostedt <rostedt@goodmis.org> - 2016-07-03 22:40 +0200
  [for-next][PATCH 02/12] tracing: Move filtered_pid helper functions into trace.c Steven Rostedt <rostedt@goodmis.org> - 2016-07-03 22:40 +0200
  [for-next][PATCH 03/12] tracing: Move the pid_list seq_file functions to be global Steven Rostedt <rostedt@goodmis.org> - 2016-07-03 22:40 +0200
  [for-next][PATCH 07/12] tracing: Choose static tp_printk buffer by explicit nesting count Steven Rostedt <rostedt@goodmis.org> - 2016-07-03 22:40 +0200
  [for-next][PATCH 08/12] tracing: Add trace_printk sample code Steven Rostedt <rostedt@goodmis.org> - 2016-07-03 22:40 +0200

csiph-web