[PATCH v2 4/5] perf x86 evlist: Update comments on topdown regrouping

From: Ian Rogers
Date: Thu Mar 06 2025 - 21:39:58 EST


From: Dapeng Mi <dapeng1.mi@xxxxxxxxxxxxxxx>

Update to remove comments about groupings not working and with the:
```
perf stat -e "{instructions,slots},{cycles,topdown-retiring}"
```
case that now works.

Signed-off-by: Ian Rogers <irogers@xxxxxxxxxx>
---
tools/perf/arch/x86/util/evlist.c | 27 ++++++---------------------
1 file changed, 6 insertions(+), 21 deletions(-)

diff --git a/tools/perf/arch/x86/util/evlist.c b/tools/perf/arch/x86/util/evlist.c
index ed205d1b207d..7905a28d7734 100644
--- a/tools/perf/arch/x86/util/evlist.c
+++ b/tools/perf/arch/x86/util/evlist.c
@@ -39,28 +39,13 @@ int arch_evlist__cmp(const struct evsel *lhs, const struct evsel *rhs)
* 26,319,024 slots
* 2,427,791 instructions
* 2,683,508 topdown-retiring
- *
- * If slots event and topdown metrics events are not in same group, the
- * topdown metrics events must be first event after the slots event group,
- * otherwise topdown metrics events can't be regrouped correctly, e.g.
- *
- * a. perf stat -e "{instructions,slots},cycles,topdown-retiring" -C0 sleep 1
- * WARNING: events were regrouped to match PMUs
- * Performance counter stats for 'CPU(s) 0':
- * 17,923,134 slots
- * 2,154,855 instructions
- * 3,015,058 cycles
- * <not supported> topdown-retiring
- *
- * If slots event and topdown metrics events are in two groups, the group which
- * has topdown metrics events must contain only the topdown metrics event,
- * otherwise topdown metrics event can't be regrouped correctly as well, e.g.
- *
- * a. perf stat -e "{instructions,slots},{topdown-retiring,cycles}" -C0 sleep 1
+ * e. slots event and metrics event are in a group and not adjacent
+ * perf stat -e "{instructions,slots},cycles,topdown-retiring" -C0 sleep 1
* WARNING: events were regrouped to match PMUs
- * Error:
- * The sys_perf_event_open() syscall returned with 22 (Invalid argument) for
- * event (topdown-retiring)
+ * 68,433,522 slots
+ * 8,856,102 topdown-retiring
+ * 7,791,494 instructions
+ * 11,469,513 cycles
*/
if (topdown_sys_has_perf_metrics() &&
(arch_evsel__must_be_in_group(lhs) || arch_evsel__must_be_in_group(rhs))) {
--
2.49.0.rc0.332.g42c0ae87b1-goog