import PULS_20160108

[GitHub/mt8127/android_kernel_alcatel_ttab.git] / Documentation / trace / ftrace.txt

diff --git a/Documentation/trace/ftrace.txt b/Documentation/trace/ftrace.txt
index bfe8c29b1f1d84cf5c6a9d71c3c69b20f2bdf12f..29064c3bfcd1bae1b0f39d6078a3f28e34ed3803 100644 (file)
--- a/Documentation/trace/ftrace.txt
+++ b/Documentation/trace/ftrace.txt
@@ -2013,6 +2013,35 @@ will produce:
  1)   1.449 us    |             }
 
 
  1)   1.449 us    |             }
 
 

+You can disable the hierarchical function call formatting and instead print a
+flat list of function entry and return events.  This uses the format described
+in the Output Formatting section and respects all the trace options that
+control that formatting.  Hierarchical formatting is the default.
+
+       hierachical: echo nofuncgraph-flat > trace_options
+       flat: echo funcgraph-flat > trace_options
+
+  ie:
+
+  # tracer: function_graph
+  #
+  # entries-in-buffer/entries-written: 68355/68355   #P:2
+  #
+  #                              _-----=> irqs-off
+  #                             / _----=> need-resched
+  #                            | / _---=> hardirq/softirq
+  #                            || / _--=> preempt-depth
+  #                            ||| /     delay
+  #           TASK-PID   CPU#  ||||    TIMESTAMP  FUNCTION
+  #              | |       |   ||||       |         |
+                sh-1806  [001] d...   198.843443: graph_ent: func=_raw_spin_lock
+                sh-1806  [001] d...   198.843445: graph_ent: func=__raw_spin_lock
+                sh-1806  [001] d..1   198.843447: graph_ret: func=__raw_spin_lock
+                sh-1806  [001] d..1   198.843449: graph_ret: func=_raw_spin_lock
+                sh-1806  [001] d..1   198.843451: graph_ent: func=_raw_spin_unlock_irqrestore
+                sh-1806  [001] d...   198.843453: graph_ret: func=_raw_spin_unlock_irqrestore
+
+

 You might find other useful features for this tracer in the
 following "dynamic ftrace" section such as tracing only specific
 functions or tasks.
 You might find other useful features for this tracer in the
 following "dynamic ftrace" section such as tracing only specific
 functions or tasks.