Re: [PATCH v1 3/3] perf parse-events: Add 'X' modifier to exclude an event from being regrouped

[Ian Rogers <irogers@google.com>]

On Fri, Oct 17, 2025 at 12:25 AM Mi, Dapeng <dapeng1.mi@linux.intel.com> wrote:
> Hi Ian,
>
> It looks the "X" modifier only works for the cases without explicit group,
> like this.
>
> sudo ./perf record -e cpu/mem-stores/ppu,cpu/slots/uX -- sleep 1
> [ perf record: Woken up 2 times to write data ]
> [ perf record: Captured and wrote 0.019 MB perf.data (7 samples) ]
>
> Once there is an explicit group, the "X" modifier would not work and the
> regroup still happens, e.g.,
>
> sudo ./perf record -e '{cpu/mem-stores/ppu,cpu/slots/uX}' -- sleep 1
> WARNING: events were regrouped to match PMUs
> [ perf record: Woken up 2 times to write data ]
> [ perf record: Captured and wrote 0.019 MB perf.data (7 samples) ]
>
> I suppose we should enhance the "X" modifier and make it work in 2nd case
> as well. How's your idea?

Hi Dapeng,

hopefully fixed in:
https://lore.kernel.org/lkml/20251017165753.206608-1-irogers@google.com/

PTAL. Thanks,
Ian




> Thanks,
>
> Dapeng Mi
>
> > ference|ops|access|misses|miss)