Re: [PATCH 5/6] ARM: Make oprofile depend on CONFIG_HW_PERF_EVENTS

Robert Richter
2010-09-16T13:34:44Z

On 13.09.10 04:39:52, Will Deacon wrote:
> Hi Matt,
>
> On Mon, 2010-09-13 at 07:07 +0100, Matt Fleming wrote:
> > Currently, oprofile support is only functional if CONFIG_HW_PERF_EVENTS
> > is set. If this symbol is not set, oprofile initialisation will fail at
> > runtime. Instead of allowing the oprofile code to build but fail at
> > runtime it seems less confusing to not allow the code to be built unless
> > hardware performance counter support is available.
> >
> > Signed-off-by: Matt Fleming <matt@console-pimps.org>
> > ---
> > arch/arm/Kconfig | 2 +-
> > arch/arm/oprofile/common.c | 9 ---------
> > 2 files changed, 1 insertions(+), 10 deletions(-)

> When oprofile_arch_init fails (-ENODEV), oprofile will fall back to
> timer mode. With this patch, how can you make use of a timer fallback?

True, if you want an error at compile time, maybe we use the #error
pragma instead. But falling back to timer mode is fine to me too.
Will leave that decision to the arm folks.

-Robert

>
> I'll try and get around to testing the rest of this series today.
>
> Cheers,
>
> Will
>
>
>
>

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