perf stat includes option to specify aggr_mode to display
per-socket, per-core, per-die, per-node counter details.
Also there is option -A ( AGGR_NONE, -no-aggr ), where the
counter values are displayed for each cpu along with "CPU"
value in one field of the output.
Each of the aggregate mode uses the information fetched
from "/sys/devices/system/cpu/cpuX/topology" like core_id,
physical_package_id. Utility functions in "cpumap.c" fetches
this information and populates the socket id, core id, cpu etc.
If the platform does not expose the topology information,
these values will be set to -1. Example, in case of powerpc,
details like physical_package_id is restricted to be exposed
in pSeries platform. So id.socket, id.core, id.cpu all will
be set as -1.
In case of displaying socket or die value, there is no check
done in the "aggr_printout" function to see if it points to
valid socket id or die. But for displaying "cpu" value, there
is a check for "if (id.core > -1)". In case of powerpc pSeries
where detail like physical_package_id is restricted to be
exposed, id.core will be set to -1. Hence the column or field
itself for CPU won't be displayed in the output.
Result for per-socket:
<<>>
perf stat -e branches --per-socket -a true
Performance counter stats for 'system wide':
S-1 32 416,851 branches
<<>>
Here S has -1 in above result. But with -A option which also
expects CPU in one column in the result, below is observed.
<<>>
/bin/perf stat -e instructions -A -a true
Performance counter stats for 'system wide':
47,146 instructions
45,226 instructions
43,354 instructions
45,184 instructions
<<>>
If the cpu id value is pointing to -1 also, it makes sense
to display the column in the output to replicate the behaviour
or to be in precedence with other aggr options(like per-socket,
per-core). Remove the check "id.core" so that CPU field gets
displayed in the output.
After the fix:
<<>>
perf stat -e instructions -A -a true
Performance counter stats for 'system wide':
CPU-1 64,034 instructions
CPU-1 68,941 instructions
CPU-1 59,418 instructions
CPU-1 70,478 instructions
CPU-1 65,201 instructions
CPU-1 63,704 instructions
<<>>
This is caught while running "perf test" for
"stat+json_output.sh" and "stat+csv_output.sh".
Reported-by: Disha Goel <disg...@linux.vnet.ibm.com>
Signed-off-by: Athira Rajeev <atraj...@linux.vnet.ibm.com>
---
tools/perf/util/stat-display.c | 6 ++----
1 file changed, 2 insertions(+), 4 deletions(-)
diff --git a/tools/perf/util/stat-display.c b/tools/perf/util/stat-display.c
index b82844cb0ce7..1b751a730271 100644
--- a/tools/perf/util/stat-display.c
+++ b/tools/perf/util/stat-display.c
@@ -168,10 +168,9 @@ static void aggr_printout(struct perf_stat_config *config,
id.socket,
id.die,
id.core);
- } else if (id.core > -1) {
+ } else
fprintf(config->output, "\"cpu\" : \"%d\", ",
id.cpu.cpu);
- }
} else {
if (evsel->percore && !config->percore_show_thread) {
fprintf(config->output, "S%d-D%d-C%*d%s",
@@ -179,11 +178,10 @@ static void aggr_printout(struct perf_stat_config *config,
id.die,
config->csv_output ? 0 : -3,
id.core, config->csv_sep);
- } else if (id.core > -1) {
+ } else
fprintf(config->output, "CPU%*d%s",
config->csv_output ? 0 : -7,
id.cpu.cpu, config->csv_sep);
- }
}
break;
case AGGR_THREAD:
--
2.31.1
