Re: [PATCH 0/4] perf arm-spe: Improve --itrace options

Arnaldo Carvalho de Melo
2025-09-09T06:51:14Z

On Mon, Sep 08, 2025 at 01:10:17PM +0100, James Clark wrote:
> Most people also want all the SPE samples (instructions group), not just
> the flagged samples that are put into the various memory groups. These
> should have been shown by default but weren't because the default
> interval type wasn't supported.
>
> Also when looking at this, it appears that the downsampling was behaving
> in a way that would discard samples from one group but not another.
> Improve that and the warning messages.
>
> I don't want to put fixes tags on these because it's only changing the
> defaults and the behavior, but I don't think the previous behavior was
> incorrect necessarily, just copied from tracing techs but not ideal for
> SPE.

I keep trying to find some hardware to have in my homelab to test these
series, but till then I depend on people having access to such hardware
for acks or better, tested-by, so waiting a bit for those to appear.

- Arnaldo

> Signed-off-by: James Clark <james.clark@linaro.org>
> ---
> James Clark (4):
> perf arm-spe: Show instruction sample types by default
> perf arm-spe: Downsample all sample types equally
> perf arm-spe: Display --itrace period warnings for all sample types
> perf docs: Update SPE doc to include default instructions group
>
> tools/perf/Documentation/perf-arm-spe.txt | 14 +++++---
> tools/perf/util/arm-spe.c | 53 ++++++++++++++++---------------
> 2 files changed, 37 insertions(+), 30 deletions(-)
> ---
> base-commit: 75a7b9d29215c5aa813b9620f3c56817918f9f8c
> change-id: 20250908-james-perf-spe-period-4711a566cba4
>
> Best regards,
> --
> James Clark <james.clark@linaro.org>
>