diff options
| author | Jamie Gennis <jgennis@google.com> | 2012-11-21 20:14:09 -0800 |
|---|---|---|
| committer | Colin Cross <ccross@android.com> | 2014-03-19 13:09:57 -0700 |
| commit | ca1e0afee8bd83650a060be6038614ca3838b2ab (patch) | |
| tree | f666839c95bff14125fe30240d28e5423350e3a7 /Documentation | |
| parent | 697ba9d8a8a6906607269f47ba31ff0d43fe0296 (diff) | |
trace: add non-hierarchical function_graph option
Add the 'funcgraph-flat' option to the function_graph tracer to use the default
trace printing format rather than the hierarchical formatting normally used.
Change-Id: If2900bfb86e6f8f51379f56da4f6fabafa630909
Signed-off-by: Jamie Gennis <jgennis@google.com>
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/trace/ftrace.txt | 29 |
1 files changed, 29 insertions, 0 deletions
diff --git a/Documentation/trace/ftrace.txt b/Documentation/trace/ftrace.txt index bd365988e8d8..a0dcdbc112ee 100644 --- a/Documentation/trace/ftrace.txt +++ b/Documentation/trace/ftrace.txt @@ -2017,6 +2017,35 @@ will produce: 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. |