[PATCH v6 0/5] perf stat: Support overall statistics for interval mode

Jin Yao
2020-05-20T04:29:43Z

Currently perf-stat supports to print counts at regular interval (-I),
but it's not very easy for user to get the overall statistics.

With this patchset, it supports to report the summary at the end of
interval output.

For example,

root@kbl-ppc:~# perf stat -e cycles -I1000 --interval-count 2
# time counts unit events
1.000412064 2,281,114 cycles
2.001383658 2,547,880 cycles

Performance counter stats for 'system wide':

4,828,994 cycles

2.002860349 seconds time elapsed

root@kbl-ppc:~# perf stat -e cycles,instructions -I1000 --interval-count 2
# time counts unit events
1.000389902 1,536,093 cycles
1.000389902 420,226 instructions # 0.27 insn per cycle
2.001433453 2,213,952 cycles
2.001433453 735,465 instructions # 0.33 insn per cycle

Performance counter stats for 'system wide':

3,750,045 cycles
1,155,691 instructions # 0.31 insn per cycle

2.003023361 seconds time elapsed

root@kbl-ppc:~# perf stat -M CPI,IPC -I1000 --interval-count 2
# time counts unit events
1.000435121 905,303 inst_retired.any # 2.9 CPI
1.000435121 2,663,333 cycles
1.000435121 914,702 inst_retired.any # 0.3 IPC
1.000435121 2,676,559 cpu_clk_unhalted.thread
2.001615941 1,951,092 inst_retired.any # 1.8 CPI
2.001615941 3,551,357 cycles
2.001615941 1,950,837 inst_retired.any # 0.5 IPC
2.001615941 3,551,044 cpu_clk_unhalted.thread

Performance counter stats for 'system wide':

2,856,395 inst_retired.any # 2.2 CPI
6,214,690 cycles
2,865,539 inst_retired.any # 0.5 IPC
6,227,603 cpu_clk_unhalted.thread

2.003403078 seconds time elapsed

v6:
---
1. Add comments in perf_evlist__save_aggr_prev_raw_counts.
2. Move init_stats(&walltime_nsecs_stats) under interval condition check.

Following patches are changed in v6.
perf stat: Save aggr value to first member of prev_raw_counts
perf stat: Report summary for interval mode

v5:
---
1. Create new patch "perf stat: Save aggr value to first member
of prev_raw_counts".

2. Call perf_evlist__save_aggr_prev_raw_counts to save aggr value
to first member of prev_raw_counts for AGGR_GLOBAL. Then next,
perf_stat_process_counter can create aggr values from per cpu
values.

Following patches are impacted in v5:
perf stat: Copy counts from prev_raw_counts to evsel->counts
perf stat: Save aggr value to first member of prev_raw_counts
perf stat: Report summary for interval mode

v4:
---
1. Create runtime_stat_reset.

2. Zero the aggr in perf_counts__reset and use it to reset
prev_raw_counts.

3. Move affinity setup and read_counter_cpu to a new function
read_affinity_counters. It's only called when stat_config.summary
is not set.

v3:
---
1. 'perf stat: Fix wrong per-thread runtime stat for interval mode'
is a new patch which fixes an existing issue found in test.

2. We use the prev_raw_counts for summary counts. Drop the summary_counts in v2.

3. Fix some issues.

v2:
---
Rebase to perf/core branch

Jin Yao (5):
perf stat: Fix wrong per-thread runtime stat for interval mode
perf counts: Reset prev_raw_counts counts
perf stat: Copy counts from prev_raw_counts to evsel->counts
perf stat: Save aggr value to first member of prev_raw_counts
perf stat: Report summary for interval mode

tools/perf/builtin-stat.c | 101 +++++++++++++++++++++++++-------------
tools/perf/util/counts.c | 4 +-
tools/perf/util/counts.h | 1 +
tools/perf/util/stat.c | 53 +++++++++++++++++---
tools/perf/util/stat.h | 3 ++
5 files changed, 122 insertions(+), 40 deletions(-)

--
2.17.1