Re: [PATCH V3 0/6] Generalise ARM perf-events backend for oprofile

[Matt Fleming <matt@console-pimps.org>]

On Mon, Sep 13, 2010 at 11:08:53AM +0100, Will Deacon wrote:
> Hi Matt,
> 
> On Mon, 2010-09-13 at 07:07 +0100, Matt Fleming wrote:
> > The perf-events backend for OProfile that Will Deacon wrote in
> > 8c1fc96f6fd1f361428ba805103af0d0eee65179 ("ARM: 6072/1: oprofile: use
> > perf-events framework as backend") is of use to more architectures
> > than just ARM. Move the code into drivers/oprofile/ so that SH can use
> > it instead of the nearly identical copy of its OProfile code.
> > 
> [...]
> > 
> > Note that I haven't been able to test these patches on an ARM board to
> > see if I've caused any regressions. If anyone else could do that I'd
> > appreciate it. Though, I have been able to compile this version of the
> > series.
> > 
> I've tested this patch series on a multicore Cortex-A9 board. If I
> revert patch 5/6 (ARM: Make oprofile depend on CONFIG_HW_PERF_EVENTS)
> then everything seems to work fine. Otherwise, testing without
> HW_PERF_EVENTS doesn't fall back to timer mode.
> 
> So, with the exception of the patch above:
> 
> Tested-by: Will Deacon <will.deacon@arm.com>

Hi Will, thanks for testing!

Ah yeah, making oprofile rely on CONFIG_HW_PERF_EVENTS is too
strict. I hadn't noticed that armpmu_get_pmu_id() is wrapped in
CONFIG_HW_PERF_EVENTS and had intended op->cpu_type to be NULL and so
we'd fallback to the timer mode.

This patch needs to be dropped entirely (though another patch should
conditionally include oprofile_perf.o based on CONFIG_HW_PERF_EVENT
like I had in my original series).