From 91a8c5b840f2da31280e14b6268761cf14033756 Mon Sep 17 00:00:00 2001 From: Kan Liang Date: Fri, 30 Jun 2017 10:16:56 -0400 Subject: [PATCH] perf intel-pt: Always set no branch for dummy event An earlier kernel patch allowed enabling PT and LBR at the same time on Goldmont. commit ccbebba4c6bf ("perf/x86/intel/pt: Bypass PT vs. LBR exclusivity if the core supports it") However, users still cannot use Intel PT and LBRs simultaneously. $ sudo perf record -e cycles,intel_pt//u -b -- sleep 1 Error: PMU Hardware doesn't support sampling/overflow-interrupts. PT implicitly adds dummy event in perf tool. dummy event is software event which doesn't support LBR. Always setting no branch for dummy event in Intel PT. Signed-off-by: Kan Liang Acked-by: Jiri Olsa Cc: Adrian Hunter Cc: Alexander Shishkin Cc: Andi Kleen Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/20170630141656.1626-2-kan.liang@intel.com Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/arch/x86/util/intel-pt.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/tools/perf/arch/x86/util/intel-pt.c b/tools/perf/arch/x86/util/intel-pt.c index 4a461e8ae326..db0ba8caf5a2 100644 --- a/tools/perf/arch/x86/util/intel-pt.c +++ b/tools/perf/arch/x86/util/intel-pt.c @@ -701,6 +701,7 @@ static int intel_pt_recording_options(struct auxtrace_record *itr, perf_evsel__set_sample_bit(switch_evsel, TID); perf_evsel__set_sample_bit(switch_evsel, TIME); perf_evsel__set_sample_bit(switch_evsel, CPU); + perf_evsel__reset_sample_bit(switch_evsel, BRANCH_STACK); opts->record_switch_events = false; ptr->have_sched_switch = 3; @@ -762,6 +763,7 @@ static int intel_pt_recording_options(struct auxtrace_record *itr, /* And the CPU for switch events */ perf_evsel__set_sample_bit(tracking_evsel, CPU); } + perf_evsel__reset_sample_bit(tracking_evsel, BRANCH_STACK); } /*