perf x86 evlist: Update comments on topdown regrouping

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: Dapeng Mi <dapeng1.mi@linux.intel.com>
Signed-off-by: Ian Rogers <irogers@google.com>
Link: https://lore.kernel.org/r/20250307023906.1135613-4-irogers@google.com
Signed-off-by: Namhyung Kim <namhyung@kernel.org>

diff --git a/tools/perf/arch/x86/util/evlist.c b/tools/perf/arch/x86/util/evlist.c
index ed205d1b207d4706c4d0bdae6cd1d1eceb8b488a..1969758cc8c112e04b31957902c3e3723e504f50 100644 (file)
--- 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 not 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))) {