From 5b79789291da99a918f7b375f4c5cf9eb7417758 Mon Sep 17 00:00:00 2001 From: Jamie Gennis Date: Wed, 21 Nov 2012 20:14:09 -0800 Subject: 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 --- Documentation/trace/ftrace.txt | 29 +++++++++++++++++++++++++++++ 1 file changed, 29 insertions(+) (limited to 'Documentation/trace') 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. -- cgit v1.2.3