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

[Ingo Molnar <mingo@elte.hu>]

* Peter Zijlstra <peterz@infradead.org> wrote:

> Subject: trace: add the MMIO-tracer to the tracer menu
> From: Peter Zijlstra <a.p.zijlstra@chello.nl>
> 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@chello.nl>
> CC: Pekka Paalanen <pq@iki.fi>
> ---
>  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