[PATCH v6] soc: qcom: add l2 cache perf events driver

[Mark Rutland]

Hi Neil,

On Wed, Sep 21, 2016 at 05:12:54PM -0400, Neil Leeder wrote:
> Adds perf events support for L2 cache PMU.
> 
> The L2 cache PMU driver is named 'l2cache_0' and can be used
> with perf events to profile L2 events such as cache hits
> and misses.
> 
> Signed-off-by: Neil Leeder <nleeder at codeaurora.org>
> ---

>  drivers/soc/qcom/Kconfig         |   9 +
>  drivers/soc/qcom/Makefile        |   1 +
>  drivers/soc/qcom/perf_event_l2.c | 948 +++++++++++++++++++++++++++++++++++++++
>  include/linux/cpuhotplug.h       |   1 +
>  4 files changed, 959 insertions(+)
>  create mode 100644 drivers/soc/qcom/perf_event_l2.c

Apologies for the delay; this has been on my todo list, but I've been a
little distracted and haven't had the time necessary to devote to this.
It's somewhat unusual given the constraint logic and the percpu uncore
component, so there's more to consider than usual.

At a high level, this will need to be moved to drivers/perf/, per [1].

Can you move the driver there, and post the result atop of v4.8-rc1 at
the end of the merge window? Until then, I can't guarantee that I'll
have the time to look at this.

Can you also give Vince's perf fuzzer [2] a spin against the driver? I
can't recall if we covered that previously, and in practice it's found a
number of issues in drivers that have otherwise looked fine. If you've
done so, it'd be worth noting in the cover.

Thanks,
Mark.

[1] http://lists.infradead.org/pipermail/linux-arm-kernel/2016-September/457188.html
[2] https://github.com/deater/perf_event_tests