perf stat: Support per-cluster aggregation
authorYicong Yang <yangyicong@hisilicon.com>
Thu, 8 Feb 2024 02:40:26 +0000 (10:40 +0800)
committerNamhyung Kim <namhyung@kernel.org>
Fri, 9 Feb 2024 22:59:53 +0000 (14:59 -0800)
commitcbc917a1b03bce85f385c1e640c9dcb02ffb9ab0
tree85bf911a310bfd4c9e3804d1959afc8441ac3a8f
parent9a440bb2e2e9a4af3a7857af42a825f61b27a18c
perf stat: Support per-cluster aggregation

Some platforms have 'cluster' topology and CPUs in the cluster will
share resources like L3 Cache Tag (for HiSilicon Kunpeng SoC) or L2
cache (for Intel Jacobsville). Currently parsing and building cluster
topology have been supported since [1].

perf stat has already supported aggregation for other topologies like
die or socket, etc. It'll be useful to aggregate per-cluster to find
problems like L3T bandwidth contention.

This patch add support for "--per-cluster" option for per-cluster
aggregation. Also update the docs and related test. The output will
be like:

[root@localhost tmp]# perf stat -a -e LLC-load --per-cluster -- sleep 5

 Performance counter stats for 'system wide':

S56-D0-CLS158    4      1,321,521,570      LLC-load
S56-D0-CLS594    4        794,211,453      LLC-load
S56-D0-CLS1030    4             41,623      LLC-load
S56-D0-CLS1466    4             41,646      LLC-load
S56-D0-CLS1902    4             16,863      LLC-load
S56-D0-CLS2338    4             15,721      LLC-load
S56-D0-CLS2774    4             22,671      LLC-load
[...]

On a legacy system without cluster or cluster support, the output will
be look like:
[root@localhost perf]# perf stat -a -e cycles --per-cluster -- sleep 1

 Performance counter stats for 'system wide':

S56-D0-CLS0   64         18,011,485      cycles
S7182-D0-CLS0   64         16,548,835      cycles

Note that this patch doesn't mix the cluster information in the outputs
of --per-core to avoid breaking any tools/scripts using it.

Note that perf recently supports "--per-cache" aggregation, but it's not
the same with the cluster although cluster CPUs may share some cache
resources. For example on my machine all clusters within a die share the
same L3 cache:
$ cat /sys/devices/system/cpu/cpu0/cache/index3/shared_cpu_list
0-31
$ cat /sys/devices/system/cpu/cpu0/topology/cluster_cpus_list
0-3

[1] commit c5e22feffdd7 ("topology: Represent clusters of CPUs within a die")

Tested-by: Jie Zhan <zhanjie9@hisilicon.com>
Reviewed-by: Tim Chen <tim.c.chen@linux.intel.com>
Reviewed-by: Ian Rogers <irogers@google.com>
Signed-off-by: Yicong Yang <yangyicong@hisilicon.com>
Cc: james.clark@arm.com
Cc: 21cnbao@gmail.com
Cc: prime.zeng@hisilicon.com
Cc: Jonathan.Cameron@huawei.com
Cc: fanghao11@huawei.com
Cc: linuxarm@huawei.com
Cc: tim.c.chen@intel.com
Cc: linux-arm-kernel@lists.infradead.org
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/r/20240208024026.2691-1-yangyicong@huawei.com
12 files changed:
tools/perf/Documentation/perf-stat.txt
tools/perf/builtin-stat.c
tools/perf/tests/shell/lib/perf_json_output_lint.py
tools/perf/tests/shell/lib/stat_output.sh
tools/perf/tests/shell/stat+csv_output.sh
tools/perf/tests/shell/stat+json_output.sh
tools/perf/tests/shell/stat+std_output.sh
tools/perf/util/cpumap.c
tools/perf/util/cpumap.h
tools/perf/util/env.h
tools/perf/util/stat-display.c
tools/perf/util/stat.h