Messages in this thread Patch in this message | | | Date | Mon, 8 Nov 2010 10:18:58 +0100 | From | Uwe Kleine-König <> | Subject | Re: [PATCH 6/6] ARM: ftrace: enable function graph tracer |
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On Sat, Nov 06, 2010 at 07:06:28PM +0000, Catalin Marinas wrote: > On Saturday, November 6, 2010, Rabin Vincent <rabin@rab.in> wrote: > > Add the options to enable the function graph tracer on ARM. Function > > graph tracer support requires frame pointers, so exclude Thumb-2 and > > also explicitly select FRAME_POINTER in FUNCTION_GRAPH_TRACER since > > FUNCTION_TRACER doesn't select FRAME_POINTER when ARM_UNWIND is used > > Therefore, with GCC 4.4.0+, you get plain function tracing without frame > > pointers, but you'll need them if you want function graph tracing. > ..... > > --- a/kernel/trace/Kconfig > > +++ b/kernel/trace/Kconfig > > @@ -141,6 +141,7 @@ config FUNCTION_TRACER > > > > config FUNCTION_GRAPH_TRACER > > bool "Kernel Function Graph Tracer" > > + select FRAME_POINTER if ARM_UNWIND > > Would it be better to modify FRAME_POINTER definition in the ARM > Kconfig so that it is enabled automatically when FUNCTION_GRAPH_TRACER > is enabled? I don't like that suggestion much because it hides the dependency. Moreover a "default y if FUNCTION_GRAPH_TRACER" doesn't work if a precondition for FRAME_POINTER isn't true. Rabin's approach at least generates a warning.
Best regards Uwe
-- Pengutronix e.K. | Uwe Kleine-König | Industrial Linux Solutions | http://www.pengutronix.de/ | -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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