From 7d189cadbeebc778fe19c245447d155458e6f1e3 Mon Sep 17 00:00:00 2001 From: Adrian Hunter Date: Tue, 24 May 2022 10:54:29 +0300 Subject: [PATCH] perf intel-pt: Track sideband system-wide when needed User space tasks can migrate between CPUs, so when tracing selected CPUs, sideband for all CPUs is still needed. This is in preparation for allowing system-wide events on all CPUs while the user requested events are on only user requested CPUs. Signed-off-by: Adrian Hunter Acked-by: Ian Rogers Acked-by: Namhyung Kim Cc: Alexey Bayduraev Cc: Jiri Olsa Cc: Leo Yan Link: https://lore.kernel.org/r/20220524075436.29144-9-adrian.hunter@intel.com Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/arch/x86/util/intel-pt.c | 18 ++++++++++-------- 1 file changed, 10 insertions(+), 8 deletions(-) diff --git a/tools/perf/arch/x86/util/intel-pt.c b/tools/perf/arch/x86/util/intel-pt.c index 0ee93894a0da..06c2cdfd8f2f 100644 --- a/tools/perf/arch/x86/util/intel-pt.c +++ b/tools/perf/arch/x86/util/intel-pt.c @@ -864,20 +864,22 @@ static int intel_pt_recording_options(struct auxtrace_record *itr, /* Add dummy event to keep tracking */ if (opts->full_auxtrace) { + bool need_system_wide_tracking; struct evsel *tracking_evsel; - err = parse_events(evlist, "dummy:u", NULL); - if (err) - return err; + /* + * User space tasks can migrate between CPUs, so when tracing + * selected CPUs, sideband for all CPUs is still needed. + */ + need_system_wide_tracking = evlist->core.has_user_cpus && + !intel_pt_evsel->core.attr.exclude_user; - tracking_evsel = evlist__last(evlist); + tracking_evsel = evlist__add_aux_dummy(evlist, need_system_wide_tracking); + if (!tracking_evsel) + return -ENOMEM; evlist__set_tracking_event(evlist, tracking_evsel); - tracking_evsel->core.attr.freq = 0; - tracking_evsel->core.attr.sample_period = 1; - - tracking_evsel->no_aux_samples = true; if (need_immediate) tracking_evsel->immediate = true; -- 2.25.1