Re: [PATCH 00/20] perf vendors events arm64: Multiple Arm CPUs
From: Robin Murphy
Date: Wed May 18 2022 - 08:42:59 EST
On 2022-05-18 09:15, John Garry wrote:
On 17/05/2022 15:32, Robin Murphy wrote:
On 2022-05-10 11:47, Nick Forrington wrote:
Add Performance Monitoring Unit event data for the Arm CPUs listed
below.
Changesets are dependent due to incremental updates to the common events
file and mapfile.csv.
Data is sourced from https://github.com/ARM-software/data
Nick Forrington (20):
perf vendors events arm64: Arm Cortex-A5
perf vendors events arm64: Arm Cortex-A7
perf vendors events arm64: Arm Cortex-A8
perf vendors events arm64: Arm Cortex-A9
perf vendors events arm64: Arm Cortex-A15
perf vendors events arm64: Arm Cortex-A17
perf vendors events arm64: Arm Cortex-A32
Obligatory question over anything relating to the above CPUs being in
an "arch/arm64" directory... ;)
If we were to add to arm32/arm then the common event numbers and maybe
other JSONs in future would need to be duplicated.
Would there be any reason to add to arm32/arm apart to from being
strictly proper? Maybe if lots of other 32b support for other vendors
came along then it could make sense (to separate them out).
That's the heart of the question, really. At best it seems unnecessarily
confusing as-is. AFAICS either the naming isn't functional, wherein it
would potentially make the most sense to rename the whole thing
"pmu-events/arch/arm" if it's merely for categorising Arm architectures
in general, or it is actually tied to the host triplet, in which case
the above patches are most likely useless.
I'd agree that there doesn't seem much point in trying to separate
things along relatively arbitrary lines if it *isn't* functionally
necessary - the PMUv2 common events look to be a straightforward subset
of the PMUv3 ones, but then there's Cortex-A32 anyway, plus most of the
already-supported CPUs could equally run an AArch32 perf tool as well.
Thanks,
Robin.