perf test: Test perf lock contention CSV output

To verify CSV output, just check the number of separators (",") using
the tr and wc commands like this.

grep -v "^#" ${result} | tr -d -c | wc -c

Now it expects 6 columns (and 5 separators) in the output, but it may
be changed later so count the field in the header first and compare it
to the actual output lines.

$ cat ${result}
# output: contended, total wait, max wait, avg wait, type, caller
1, 28787, 28787, 28787, spinlock, raw_spin_rq_lock_nested+0x1b

The test looks like below now:

$ sudo ./perf test -v contention
86: kernel lock contention analysis test :
--- start ---
test child forked, pid 2705822
Testing perf lock record and perf lock contention
Testing perf lock contention --use-bpf
Testing perf lock record and perf lock contention at the same time
Testing perf lock contention --threads
Testing perf lock contention --lock-addr
Testing perf lock contention --type-filter (w/ spinlock)
Testing perf lock contention --lock-filter (w/ tasklist_lock)
Testing perf lock contention --callstack-filter (w/ unix_stream)
Testing perf lock contention --callstack-filter with task aggregation
Testing perf lock contention CSV output
test child finished with 0
---- end ----
kernel lock contention analysis test: Ok

Acked-by: Ian Rogers <[e-mail]>
Cc: Hao Luo <[e-mail]>
Cc: Peter Zijlstra <[e-mail]>
Cc: Adrian Hunter <[e-mail]>
Cc: Arnaldo Carvalho de Melo <[e-mail]>
Cc: Jiri Olsa <[e-mail]>
Cc: Ingo Molnar <[e-mail]>
Cc: Song Liu <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Namhyung Kim <[e-mail]>

tools/perf/tests/shell/lock_contention.sh

···
 	fi
 }
 
+test_csv_output()
+{
+	echo "Testing perf lock contention CSV output"
+	perf lock contention -i ${perfdata} -E 1 -x , --output ${result}
+	# count the number of commas in the header
+	# it should have 5: contended, total-wait, max-wait, avg-wait, type, caller
+	header=$(grep "# output:" ${result} | tr -d -c , | wc -c)
+	if [ "${header}" != "5" ]; then
+		echo "[Fail] Recorded result does not have enough output columns: ${header} != 5"
+		err=1
+		exit
+	fi
+	# count the number of commas in the output
+	output=$(grep -v "^#" ${result} | tr -d -c , | wc -c)
+	if [ "${header}" != "${output}" ]; then
+		echo "[Fail] Recorded result does not match the number of commas: ${header} != ${output}"
+		err=1
+		exit
+	fi
+
+	if ! perf lock con -b true > /dev/null 2>&1 ; then
+		echo "[Skip] No BPF support"
+		return
+	fi
+
+	# the perf lock contention output goes to the stderr
+	perf lock con -a -b -E 1 -x , --output ${result} -- perf bench sched messaging > /dev/null 2>&1
+	output=$(grep -v "^#" ${result} | tr -d -c , | wc -c)
+	if [ "${header}" != "${output}" ]; then
+		echo "[Fail] BPF result does not match the number of commas: ${header} != ${output}"
+		err=1
+		exit
+	fi
+}
+
 check
 
 test_record
···
 test_lock_filter
 test_stack_filter
 test_aggr_task_stack_filter
+test_csv_output
 
 exit ${err}