diff options
| author | Jamie Gennis <jgennis@google.com> | 2012-11-21 20:14:09 -0800 |
|---|---|---|
| committer | Arve Hjønnevåg <arve@android.com> | 2013-07-01 14:16:22 -0700 |
| commit | 5b79789291da99a918f7b375f4c5cf9eb7417758 (patch) | |
| tree | 055e29e60323490d3fe7244508139e8f7c533851 /Documentation/trace/ftrace.txt | |
| parent | 7533724d29d13cde4f8b839ec066c5941a6674c8 (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/trace/ftrace.txt')
| -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 bfe8c29b1f1d..29064c3bfcd1 100644 --- a/Documentation/trace/ftrace.txt +++ b/Documentation/trace/ftrace.txt @@ -2013,6 +2013,35 @@ 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. |