From 762a05c561bcc36ccde6a25e268888383e6adb83 Mon Sep 17 00:00:00 2001 From: Ian Rogers Date: Thu, 23 Sep 2021 00:46:12 -0700 Subject: [PATCH] perf metric: Allow metrics with no events A metric may be a constant value, for example, some SMT metrics are constant 0 if #smt_on is 0. If we eliminate all the events then there is no printing. Fix this by forcing metrics like this to have a duration_time tool event, previously the metric would fail when parsing the events with a parse error. Signed-off-by: Ian Rogers Tested-by: John Garry Acked-by: Jiri Olsa Cc: Alexander Shishkin Cc: Andi Kleen Cc: Ingo Molnar Cc: Jin Yao Cc: Kajol Jain Cc: Mark Rutland Cc: Namhyung Kim Cc: Paul Clarke Cc: Peter Zijlstra Cc: Sandeep Dasgupta Cc: Stephane Eranian Link: https://lore.kernel.org/r/20210923074616.674826-10-irogers@google.com [ Reflow one __parse_events() call so that a ternary operation gets in a single line ] Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/metricgroup.c | 106 ++++++++++++++++++++++-------------------- 1 file changed, 56 insertions(+), 50 deletions(-) diff --git a/tools/perf/util/metricgroup.c b/tools/perf/util/metricgroup.c index 046fb3f..8ba5370 100644 --- a/tools/perf/util/metricgroup.c +++ b/tools/perf/util/metricgroup.c @@ -198,65 +198,69 @@ static struct evsel *find_evsel_group(struct evlist *perf_evlist, struct evsel *ev, *current_leader = NULL; struct expr_id_data *val_ptr; int i = 0, matched_events = 0, events_to_match; - const int idnum = (int)hashmap__size(pctx->ids); + int idnum = (int)hashmap__size(pctx->ids); - /* - * duration_time is always grouped separately, when events are grouped - * (ie has_constraint is false) then ignore it in the matching loop and - * add it to metric_events at the end. - */ - if (!has_constraint && - hashmap__find(pctx->ids, "duration_time", (void **)&val_ptr)) - events_to_match = idnum - 1; - else - events_to_match = idnum; - - evlist__for_each_entry (perf_evlist, ev) { + if (idnum != 0) { /* - * Events with a constraint aren't grouped and match the first - * events available. + * duration_time is always grouped separately, when events are + * grouped (ie has_constraint is false) then ignore it in the + * matching loop and add it to metric_events at the end. */ - if (has_constraint && ev->weak_group) - continue; - /* Ignore event if already used and merging is disabled. */ - if (metric_no_merge && test_bit(ev->core.idx, evlist_used)) - continue; - if (!has_constraint && !evsel__has_leader(ev, current_leader)) { + events_to_match = idnum; + if (!has_constraint && hashmap__find(pctx->ids, "duration_time", (void **)&val_ptr)) + events_to_match--; + + evlist__for_each_entry(perf_evlist, ev) { + /* + * Events with a constraint aren't grouped and match the + * first events available. + */ + if (has_constraint && ev->weak_group) + continue; + /* Ignore event if already used and merging is disabled. */ + if (metric_no_merge && test_bit(ev->core.idx, evlist_used)) + continue; + if (!has_constraint && !evsel__has_leader(ev, current_leader)) { + /* + * Start of a new group, discard the whole match + * and start again. + */ + matched_events = 0; + memset(metric_events, 0, sizeof(struct evsel *) * idnum); + current_leader = evsel__leader(ev); + } /* - * Start of a new group, discard the whole match and - * start again. + * Check for duplicate events with the same name. For + * example, uncore_imc/cas_count_read/ will turn into 6 + * events per socket on skylakex. Only the first such + * event is placed in metric_events. If events aren't + * grouped then this also ensures that the same event in + * different sibling groups aren't both added to + * metric_events. */ - matched_events = 0; - memset(metric_events, 0, - sizeof(struct evsel *) * idnum); - current_leader = evsel__leader(ev); + if (contains_event(metric_events, matched_events, ev->name)) + continue; + /* Does this event belong to the parse context? */ + if (hashmap__find(pctx->ids, ev->name, (void **)&val_ptr)) + metric_events[matched_events++] = ev; + + if (matched_events == events_to_match) + break; } + } else { /* - * Check for duplicate events with the same name. For example, - * uncore_imc/cas_count_read/ will turn into 6 events per socket - * on skylakex. Only the first such event is placed in - * metric_events. If events aren't grouped then this also - * ensures that the same event in different sibling groups - * aren't both added to metric_events. + * There are no events to match, but we need to associate the + * metric with an event for printing. A duration_time event was + * parsed for this. */ - if (contains_event(metric_events, matched_events, ev->name)) - continue; - /* Does this event belong to the parse context? */ - if (hashmap__find(pctx->ids, ev->name, (void **)&val_ptr)) - metric_events[matched_events++] = ev; - - if (matched_events == events_to_match) - break; + idnum = 1; + events_to_match = 0; } - if (events_to_match != idnum) { /* Add the first duration_time. */ - evlist__for_each_entry(perf_evlist, ev) { - if (!strcmp(ev->name, "duration_time")) { - metric_events[matched_events++] = ev; - break; - } - } + ev = evlist__find_evsel_by_str(perf_evlist, "duration_time"); + if (ev) + metric_events[matched_events++] = ev; } if (matched_events != idnum) { @@ -320,9 +324,10 @@ static int metricgroup__setup_events(struct list_head *groups, list_for_each_entry (m, groups, nd) { struct evsel **metric_events; struct metric_ref *metric_refs = NULL; + const size_t ids_size = hashmap__size(m->pctx->ids); metric_events = calloc(sizeof(void *), - hashmap__size(m->pctx->ids) + 1); + ids_size == 0 ? 2 : ids_size + 1); if (!metric_events) { ret = -ENOMEM; break; @@ -1240,7 +1245,8 @@ static int parse_groups(struct evlist *perf_evlist, const char *str, goto out; pr_debug("adding %s\n", extra_events.buf); bzero(&parse_error, sizeof(parse_error)); - ret = __parse_events(perf_evlist, extra_events.buf, &parse_error, fake_pmu); + ret = __parse_events(perf_evlist, extra_events.len > 0 ? extra_events.buf : "duration_time", + &parse_error, fake_pmu); if (ret) { parse_events_print_error(&parse_error, extra_events.buf); goto out; -- 2.7.4