When recording PEBS-via-PT, the kernel will not accept the intel_pt
event with register sampling e.g.
# perf record --kcore -c 10000 -e '{intel_pt/branch=0/,branch-loads/aux-output/ppp}' -I -- ls -l
Error:
intel_pt/branch=0/: PMU Hardware doesn't support sampling/overflow-interrupts. Try 'perf stat'
Fix by suppressing register sampling on the intel_pt evsel.
Committer notes:
Adrian informed that this is only available from Tremont onwards, so on
older processors the error continues the same as before.
Fixes:
9e64cefe4335b ("perf intel-pt: Process options for PEBS event synthesis")
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Luwei Kang <luwei.kang@intel.com>
Link: http://lore.kernel.org/lkml/20200630133935.11150-2-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
}
evsel->core.attr.freq = 0;
evsel->core.attr.sample_period = 1;
+ evsel->no_aux_samples = true;
intel_pt_evsel = evsel;
opts->full_auxtrace = true;
}
if (callchain && callchain->enabled && !evsel->no_aux_samples)
evsel__config_callchain(evsel, opts, callchain);
- if (opts->sample_intr_regs) {
+ if (opts->sample_intr_regs && !evsel->no_aux_samples) {
attr->sample_regs_intr = opts->sample_intr_regs;
evsel__set_sample_bit(evsel, REGS_INTR);
}
- if (opts->sample_user_regs) {
+ if (opts->sample_user_regs && !evsel->no_aux_samples) {
attr->sample_regs_user |= opts->sample_user_regs;
evsel__set_sample_bit(evsel, REGS_USER);
}