When monitoring a large number of events (e.g., with wildcards such as
--event 'syscalls:sys_enter_*'), many matched events will return a count
of zero. This clutters the output, making it difficult to spot the
active events.
Add a new option --hide-zero-events to suppress printing events that
have a count of zero.
To prevent formatting and diagnostic issues, the zero-skipping logic
implements the following rules:
1. In metric-only mode (i.e., --metric-only), columns must remain
aligned in the output grid. We evaluate config->metric_only first
to avoid skipping zero-valued columns, preventing values from
shifting left and aligning under incorrect headers
2. For explicitly requested events, we ensure they are not silently
hidden if they are unsupported. We only hide a zero-count event
if counter->supported is true, ensuring that unsupported explicit
events still report "<not supported>"
Signed-off-by: Aaron Tomlin <atomlin@atomlin.com>
Reviewed-by: Ian Rogers <irogers@google.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Specifying --field-separator option is stating you want CSV output.
Passing both --field-separator and --json-output is then stating
you want output to be in CSV and JSON format at same time.
Currently this combination is not rejected, and the outcome
is a malformed combination of CSV and JSON output.
This is because of inconsistencies in various printing functions,
some of them have if-else chains that start with
"Should I print JSON?", and some start with "Should I print CSV?".
Example of current output:
$ tools/perf/perf stat -x , -j -e cpu-migrations true
{"counter-value" : "0.000000", "unit" : "", "event" : "cpu-migrations", "event-runtime" : 474817, "pcnt-running" : 100.00,,
Instead reject the option combination,
with a helpful error message and non-zero exit code.
Example of new output:
$ tools/perf/perf stat -x , -j true
cannot use both --field-separator and --json-output
Usage: perf stat [<options>] [<command>]
-x, --field-separator <separator>
print counts with custom separator
-j, --json-output print counts in JSON format
Signed-off-by: Ivan Lazaric <ivan.lazaric1@gmail.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
On s390 'perf test's 'perf stat tests', subtest test_hybrid fails for
z/VM systems. The root cause is this statement:
$(perf stat -a -- sleep 0.1 2>&1 |\
grep -E "/cpu-cycles/[uH]*| cpu-cycles[:uH]* -c)
The 'perf stat' output on a s390 z/VM system is
# perf stat -a -- sleep 0.1 2>&1
Performance counter stats for 'system wide':
56 context-switches # 46.3 cs/sec cs_per_second
1,210.41 msec cpu-clock # 11.9 CPUs CPUs_utilized
12 cpu-migrations # 9.9 migrations/sec ...
81 page-faults # 66.9 faults/sec ...
0.100891009 seconds time elapsed
The grep command does not match any single line and exits with error
code 1.
As the bash script is executed with 'set -e', it aborts with the first
error code being non-zero.
Fix this and use 'wc -l' to count matching lines instead of 'grep ... -c'.
Output before:
# perf test 102
102: perf stat tests : FAILED!
#
Output after:
# perf test 102
102: perf stat tests : Ok
#
Fixes: bb6e7cb11d ("perf tools: Add fallback for exclude_guest")
Reviewed-by: Ian Rogers <irogers@google.com>
Reviewed-by: James Clark <james.clark@linaro.org>
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Jan Polensky <japo@linux.ibm.com>
Cc: linux-s390@vger.kernel.org
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Sumanth Korikkar <sumanthk@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Add a test that if an offline CPU is requested perf stat will fail.
$ perf test -vv "perf stat tests"
101: perf stat tests:
--- start ---
test child forked, pid 46965
Basic stat command test
Basic stat command test [Success]
Null stat command test
Null stat command test [Success]
Offline CPU stat command test (cpu 8)
Offline CPU stat command test [Success]
stat record and report test
stat record and report test [Success]
stat record and script test
stat record and script test [Success]
stat repeat weak groups test
stat repeat weak groups test [Success]
Topdown event group test
Topdown event group test [Success]
Topdown weak groups test
Topdown weak groups test [Skipped event parsing failed]
cputype test
cputype test [Success]
hybrid test
hybrid test [Success]
---- end(0) ----
101: perf stat tests : Ok
Reported-by: Thomas Richter <tmricht@linux.ibm.com>
Closes: https://lore.kernel.org/linux-perf-users/94313b82-888b-4f42-9fb0-4585f9e90080@linux.ibm.com/
Signed-off-by: Ian Rogers <irogers@google.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
test_stat_record_report and test_stat_record_script used default
output which triggers a bug when sending metrics. As this isn't
relevant to the test switch to using named software events.
Update the match in test_hybrid as the cycles event is now cpu-cycles
to workaround potential ARM issues.
Signed-off-by: Ian Rogers <irogers@google.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Add a loop and helper function to avoid repetition, the loop uses
arrays so switch the shell to bash. Add additional topdown group tests
where a topdown event needs to be moved beyond others and the slots
event isn't first in the target group. This replicates issues that
occur on hybrid systems where the other events are for the cpu_atom
PMU. Test with both PMU and software events. Place the slots event
later in the event list.
Signed-off-by: Ian Rogers <irogers@google.com>
Link: https://lore.kernel.org/r/20250307023906.1135613-5-irogers@google.com
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
