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Subject[PATCH 5.4 049/109] perf intel-pt: Fix recording PEBS-via-PT with registers
Date
From: Adrian Hunter <adrian.hunter@intel.com>

[ Upstream commit 75bcb8776dc987538f267ba4ba05ca43fc2b1676 ]

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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
tools/perf/arch/x86/util/intel-pt.c | 1 +
tools/perf/util/evsel.c | 4 ++--
2 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/tools/perf/arch/x86/util/intel-pt.c b/tools/perf/arch/x86/util/intel-pt.c
index d43f9dec69980..e768c02ef2ab9 100644
--- a/tools/perf/arch/x86/util/intel-pt.c
+++ b/tools/perf/arch/x86/util/intel-pt.c
@@ -596,6 +596,7 @@ static int intel_pt_recording_options(struct auxtrace_record *itr,
}
evsel->core.attr.freq = 0;
evsel->core.attr.sample_period = 1;
+ evsel->no_aux_samples = true;
intel_pt_evsel = evsel;
opts->full_auxtrace = true;
}
diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index abc7fda4a0fe1..a844715a352d8 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -1028,12 +1028,12 @@ void perf_evsel__config(struct evsel *evsel, struct record_opts *opts,
if (callchain && callchain->enabled && !evsel->no_aux_samples)
perf_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;
perf_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;
perf_evsel__set_sample_bit(evsel, REGS_USER);
}
--
2.25.1


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