perf evlist: Keep topdown counters in weak group
On Intel Icelake, topdown events must always be grouped with a slots
event as leader. When a metric is parsed a weak group is formed and
retried if perf_event_open fails. The retried events aren't grouped
breaking the slots leader requirement. This change modifies the weak
group "reset" behavior so that topdown events aren't broken from the
group for the retry.
$ perf stat -e '{slots,topdown-bad-spec,topdown-be-bound,topdown-fe-bound,topdown-retiring,branch-instructions,branch-misses,bus-cycles,cache-misses,cache-references,cpu-cycles,instructions,mem-loads,mem-stores,ref-cycles,baclears.any,ARITH.DIVIDER_ACTIVE}:W' -a sleep 1
Performance counter stats for 'system wide':
47,867,188,483 slots (92.27%)
<not supported> topdown-bad-spec
<not supported> topdown-be-bound
<not supported> topdown-fe-bound
<not supported> topdown-retiring
2,173,346,937 branch-instructions (92.27%)
10,540,253 branch-misses # 0.48% of all branches (92.29%)
96,291,140 bus-cycles (92.29%)
6,214,202 cache-misses # 20.120 % of all cache refs (92.29%)
30,886,082 cache-references (76.91%)
11,773,726,641 cpu-cycles (84.62%)
11,807,585,307 instructions # 1.00 insn per cycle (92.31%)
0 mem-loads (92.32%)
2,212,928,573 mem-stores (84.69%)
10,024,403,118 ref-cycles (92.35%)
16,232,978 baclears.any (92.35%)
23,832,633 ARITH.DIVIDER_ACTIVE (84.59%)
0.981070734 seconds time elapsed
After:
$ perf stat -e '{slots,topdown-bad-spec,topdown-be-bound,topdown-fe-bound,topdown-retiring,branch-instructions,branch-misses,bus-cycles,cache-misses,cache-references,cpu-cycles,instructions,mem-loads,mem-stores,ref-cycles,baclears.any,ARITH.DIVIDER_ACTIVE}:W' -a sleep 1
Performance counter stats for 'system wide':
31040189283 slots (92.27%)
8997514811 topdown-bad-spec # 28.2% bad speculation (92.27%)
10997536028 topdown-be-bound # 34.5% backend bound (92.27%)
4778060526 topdown-fe-bound # 15.0% frontend bound (92.27%)
7086628768 topdown-retiring # 22.2% retiring (92.27%)
1417611942 branch-instructions (92.26%)
5285529 branch-misses # 0.37% of all branches (92.28%)
62922469 bus-cycles (92.29%)
1440708 cache-misses # 8.292 % of all cache refs (92.30%)
17374098 cache-references (76.94%)
8040889520 cpu-cycles (84.63%)
7709992319 instructions # 0.96 insn per cycle (92.32%)
0 mem-loads (92.32%)
1515669558 mem-stores (84.68%)
6542411177 ref-cycles (92.35%)
4154149 baclears.any (92.35%)
20556152 ARITH.DIVIDER_ACTIVE (84.59%)
1.010799593 seconds time elapsed
Reviewed-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@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.garry@huawei.com>
Cc: Kim Phillips <kim.phillips@amd.com>
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Riccardo Mancini <rickyman7@gmail.com>
Cc: Shunsuke Nakamura <nakamura.shun@fujitsu.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Xing Zhengjun <zhengjun.xing@linux.intel.com>
Link: https://lore.kernel.org/r/20220517052724.283874-2-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
d98079c05b