Re: [PATCH] trace: add the MMIO-tracer to the tracer menu

From: Ingo Molnar
Date: Fri Oct 24 2008 - 07:26:00 EST



* Peter Zijlstra <peterz@xxxxxxxxxxxxx> wrote:

> Subject: trace: add the MMIO-tracer to the tracer menu
> From: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
> Date: Fri Oct 24 12:46:04 CEST 2008
>
> Add the MMIO-tracer to the tracer menu.
>
> Signed-off-by: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
> CC: Pekka Paalanen <pq@xxxxxx>
> ---
> arch/x86/Kconfig.debug | 28 ++--------------------------
> kernel/trace/Kconfig | 28 ++++++++++++++++++++++++++++
> 2 files changed, 30 insertions(+), 26 deletions(-)
>
> Index: linux-2.6/arch/x86/Kconfig.debug
> ===================================================================
> --- linux-2.6.orig/arch/x86/Kconfig.debug
> +++ linux-2.6/arch/x86/Kconfig.debug
> @@ -175,32 +175,8 @@ config IOMMU_LEAK
> Add a simple leak tracer to the IOMMU code. This is useful when you
> are debugging a buggy device driver that leaks IOMMU mappings.
>
> -config MMIOTRACE_HOOKS
> - bool
> -
> -config MMIOTRACE
> - bool "Memory mapped IO tracing"
> - depends on DEBUG_KERNEL && PCI
> - select TRACING
> - select MMIOTRACE_HOOKS
> - help
> - Mmiotrace traces Memory Mapped I/O access and is meant for
> - debugging and reverse engineering. It is called from the ioremap
> - implementation and works via page faults. Tracing is disabled by
> - default and can be enabled at run-time.
> -
> - See Documentation/tracers/mmiotrace.txt.
> - If you are not helping to develop drivers, say N.
> -
> -config MMIOTRACE_TEST
> - tristate "Test module for mmiotrace"
> - depends on MMIOTRACE && m
> - help
> - This is a dumb module for testing mmiotrace. It is very dangerous
> - as it will write garbage to IO memory starting at a given address.
> - However, it should be safe to use on e.g. unused portion of VRAM.
> -
> - Say N, unless you absolutely know what you are doing.
> +config HAVE_MMIOTRACE_SUPPORT
> + def_bool y
>
> #
> # IO delay types:
> Index: linux-2.6/kernel/trace/Kconfig
> ===================================================================
> --- linux-2.6.orig/kernel/trace/Kconfig
> +++ linux-2.6/kernel/trace/Kconfig
> @@ -194,4 +194,32 @@ config FTRACE_STARTUP_TEST
> functioning properly. It will do tests on all the configured
> tracers of ftrace.
>
> +config MMIOTRACE_HOOKS
> + bool
> +
> +config MMIOTRACE
> + bool "Memory mapped IO tracing"
> + depends on HAVE_MMIOTRACE_SUPPORT && DEBUG_KERNEL && PCI
> + select TRACING
> + select MMIOTRACE_HOOKS

change makes sense, but isnt MMIOTRACE_HOOKS basically overlapping
HAVE_MMIOTRACE_SUPPORT? So i think we could get rid of MMIOTRACE_HOOKS
altogether and just use HAVE_MMIOTRACE_SUPPORT.

Pekka?

Ingo
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