On s390 the perf test case ftrace sometimes fails as follows:
# ./perf test ftrace
79: perf ftrace tests : FAILED!
#
The failure depends on the kernel .config file. Some configurations
always work fine, some do not. The ftrace profile test mostly fails,
because the ring buffer was not large enough, and some lines
(especially the interesting ones with nanosleep in it) where dropped.
To achieve success for all tested kernel configurations, enlarge
the buffer to store the traces completely without wrapping.
The default buffer size is too small for all kernel configurations.
Set the buffer size of for the ftrace profile test to 16 MB.
Output after:
# ./perf test ftrace
79: perf ftrace tests : Ok
#
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: agordeev@linux.ibm.com
Cc: gor@linux.ibm.com
Cc: hca@linux.ibm.com
Cc: sumanthk@linux.ibm.com
Link: https://lore.kernel.org/r/20241119064856.641446-1-tmricht@linux.ibm.com
Suggested-by: Sven Schnelle <svens@linux.ibm.com>
Suggested-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
During the parallel testing, I've noticed some ftrace test failures. It
seems the regex pattern checks 100 msec of nanosleep with the error
range of 10 msec. But sometimes it's affected by other processes and
resulted in more time in the syscall.
The following output shows that it took more than 120 msec and failed.
Let's update the regex pattern so that it can allow more drifts.
perf ftrace profile test
# Total (us) Avg (us) Max (us) Count Function
121279.500 121279.500 121279.500 1 __x64_sys_clock_nanosleep
121278.400 121278.400 121278.400 1 common_nsleep
121277.800 121277.800 121277.800 1 hrtimer_nanosleep
121277.100 121277.100 121277.100 1 do_nanosleep
341760.289 56960.048 121273.400 6 schedule
176.200 25.171 31.616 7 scheduler_tick
0.923 0.923 0.923 1 native_smp_send_reschedule
345522.360 69104.472 345320.600 5 __x64_sys_execve
345486.585 69097.317 345312.700 5 do_execveat_common.isra.0
340730.300 340730.300 340730.300 1 bprm_execve
1.758 0.879 0.883 2 sched_mm_cid_before_execve
1.112 1.112 1.112 1 sched_mm_cid_after_execve
---- end(-1) ----
81: perf ftrace tests : FAILED!
Reviewed-by: Ian Rogers <irogers@google.com>
Link: https://lore.kernel.org/r/20241102231702.2262258-1-namhyung@kernel.org
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
In 'perf ftrace profile sleep 0.1' we know that we'll have an specific
kernel function that will take a bit more than 0.1 seconds and will take
place just one time, so we can add a check for that so that we validate
more than just the presence of some functions in the profile.
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt (VMware) <rostedt@goodmis.org>
Link: https://lore.kernel.org/lkml/ZrTBo7KACZeuCyLj@x1
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
