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perf bpf_counter: Fix handling of cpumap fixing hybrid

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Don't open evsels on all CPUs, open them just on the CPUs they
support. This avoids opening say an e-core event on a p-core and
getting a failure - achieve this by getting rid of the "all_cpu_map".

In install_pe functions don't use the cpu_map_idx as a CPU number,
translate the cpu_map_idx, which is a dense index into the cpu_map
skipping holes at the beginning, to a proper CPU number.

Before:
```
$ perf stat --bpf-counters -a -e cycles,instructions -- sleep 1

 Performance counter stats for 'system wide':

   <not supported>      cpu_atom/cycles/
       566,270,672      cpu_core/cycles/
   <not supported>      cpu_atom/instructions/
       572,792,836      cpu_core/instructions/           #    1.01  insn per cycle

       1.001595384 seconds time elapsed
```

After:
```
$ perf stat --bpf-counters -a -e cycles,instructions -- sleep 1

 Performance counter stats for 'system wide':

       443,299,201      cpu_atom/cycles/
     1,233,919,737      cpu_core/cycles/
       213,634,112      cpu_atom/instructions/           #    0.48  insn per cycle
     2,758,965,527      cpu_core/instructions/           #    2.24  insn per cycle

       1.001699485 seconds time elapsed
```

Fixes: 7fac83aaf2 ("perf stat: Introduce 'bperf' to share hardware PMCs with BPF")
Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
Cc: bpf@vger.kernel.org
Cc: Gabriele Monaco <gmonaco@redhat.com>
Cc: Howard Chu <howardchu95@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@linaro.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Song Liu <songliubraving@fb.com>
Cc: Tengda Wu <wutengda@huaweicloud.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This commit is contained in:
Ian Rogers 2025-10-01 11:12:28 -07:00 • committed by Arnaldo Carvalho de Melo
commit b91917c0c6
2 changed files with 12 additions and 17 deletions
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