Re: [PATCH 00/11] arm: perf: add support for heterogeneous PMUs

From: Will Deacon
Date: Mon Nov 17 2014 - 06:24:58 EST


On Fri, Nov 07, 2014 at 04:25:25PM +0000, Mark Rutland wrote:
> In systems with heterogeneous CPUs (e.g. big.LITTLE) the associated PMUs
> also differ in terms of the supported set of events, the precise
> behaviour of each of those events, and the number of event counters.
> Thus it is not possible to expose these PMUs as a single logical PMU.
>
> Instead a logical PMU is created per CPU microarchitecture, which events
> can target directly:
>
> $ perf stat \
> -e armv7_cortex_a7/config=0x11/ \
> -e armv7_cortex_a15/config=0x11/ \
> ./test
>
> Performance counter stats for './test':
>
> 7980455 armv7_cortex_a7/config=0x11/ [27.29%]
> 9947934 armv7_cortex_a15/config=0x11/ [72.66%]
>
> 0.016734833 seconds time elapsed
>
> This series is based atop of my recent preparatory rework [1,2].

Modulo the patches I commented on, the ARM perf bits look fine to me. For
those:

Acked-by: Will Deacon <will.deacon@xxxxxxx>

However, you need to get the event_filter_match change into the core code
before I can queue anything.

Will
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/