From 9d2dc632e09c0fe3a8a5890845bbd65b211fd662 Mon Sep 17 00:00:00 2001
From: Ian Rogers <irogers@google.com>
Date: Sat, 11 Mar 2023 18:15:42 -0800
Subject: perf evlist: Remove nr_groups

Maintaining the number of groups during event parsing is problematic
and since changing to sort/regroup events can only be computed by a
linear pass over the evlist. As the value is generally only used in
tests, rather than hold it in a variable compute it by passing over
the evlist when necessary.

This change highlights that libpfm's counting of groups with a single
entry disagreed with regular event parsing. The libpfm tests are
updated accordingly.

Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Florian Fischer <florian.fischer@muhq.space>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@arm.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: John Garry <john.g.garry@oracle.com>
Cc: Kajol Jain <kjain@linux.ibm.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Kim Phillips <kim.phillips@amd.com>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ravi Bangoria <ravi.bangoria@amd.com>
Cc: Sean Christopherson <seanjc@google.com>
Cc: Steinar H. Gunderson <sesse@google.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Suzuki Poulouse <suzuki.poulose@arm.com>
Cc: Xing Zhengjun <zhengjun.xing@linux.intel.com>
Link: https://lore.kernel.org/r/20230312021543.3060328-2-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 tools/perf/util/header.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

(limited to 'tools/perf/util/header.c')

diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c
index 404d816ca124..276870221ce0 100644
--- a/tools/perf/util/header.c
+++ b/tools/perf/util/header.c
@@ -786,7 +786,7 @@ static int write_pmu_mappings(struct feat_fd *ff,
 static int write_group_desc(struct feat_fd *ff,
 			    struct evlist *evlist)
 {
-	u32 nr_groups = evlist->core.nr_groups;
+	u32 nr_groups = evlist__nr_groups(evlist);
 	struct evsel *evsel;
 	int ret;
 
@@ -2807,7 +2807,6 @@ static int process_group_desc(struct feat_fd *ff, void *data __maybe_unused)
 	 * Rebuild group relationship based on the group_desc
 	 */
 	session = container_of(ff->ph, struct perf_session, header);
-	session->evlist->core.nr_groups = nr_groups;
 
 	i = nr = 0;
 	evlist__for_each_entry(session->evlist, evsel) {
-- 
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