perf test bpf-counters: Add test for BPF event modifier

JIRA: https://issues.redhat.com/browse/RHEL-33020

upstream
========
commit d9bd1d4
Author: Ian Rogers <irogers@google.com>
Date: Tue Apr 16 10:00:14 2024 -0700

description
===========
Refactor test to better enable sharing of logic, to give an idea of
progress and introduce test functions. Add test of measuring both
cycles and cycles:b simultaneously.

    Signed-off-by: Ian Rogers <irogers@google.com>
    Cc: Adrian Hunter <adrian.hunter@intel.com>
    Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
    Cc: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
    Cc: Ingo Molnar <mingo@redhat.com>
    Cc: Jiri Olsa <jolsa@kernel.org>
    Cc: Kan Liang <kan.liang@linux.intel.com>
    Cc: Mark Rutland <mark.rutland@arm.com>
    Cc: Namhyung Kim <namhyung@kernel.org>
    Cc: Peter Zijlstra <peterz@infradead.org>
    Cc: Ravi Bangoria <ravi.bangoria@amd.com>
    Cc: Song Liu <song@kernel.org>
    Cc: Thomas Richter <tmricht@linux.ibm.com>
    Link: https://lore.kernel.org/r/20240416170014.985191-2-irogers@google.com
    Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Signed-off-by: Michael Petlan <mpetlan@redhat.com>

Author: rfmvh

tools/perf/tests/shell/stat_bpf_counters.sh

@@ -4,21 +4,59 @@
 
 set -e
 
+workload="perf bench sched messaging -g 1 -l 100 -t"
+
 # check whether $2 is within +/- 20% of $1
 compare_number()
 {
-       first_num=$1
-       second_num=$2
-
-       # upper bound is first_num * 120%
-       upper=$(expr $first_num + $first_num / 5 )
-       # lower bound is first_num * 80%
-       lower=$(expr $first_num - $first_num / 5 )
-
-       if [ $second_num -gt $upper ] || [ $second_num -lt $lower ]; then
-               echo "The difference between $first_num and $second_num are greater than 20%."
-               exit 1
-       fi
+	first_num=$1
+	second_num=$2
+
+	# upper bound is first_num * 120%
+	upper=$(expr $first_num + $first_num / 5 )
+	# lower bound is first_num * 80%
+	lower=$(expr $first_num - $first_num / 5 )
+
+	if [ $second_num -gt $upper ] || [ $second_num -lt $lower ]; then
+		echo "The difference between $first_num and $second_num are greater than 20%."
+		exit 1
+	fi
+}
+
+check_counts()
+{
+	base_cycles=$1
+	bpf_cycles=$2
+
+	if [ "$base_cycles" = "<not" ]; then
+		echo "Skipping: cycles event not counted"
+		exit 2
+	fi
+	if [ "$bpf_cycles" = "<not" ]; then
+		echo "Failed: cycles not counted with --bpf-counters"
+		exit 1
+	fi
+}
+
+test_bpf_counters()
+{
+	printf "Testing --bpf-counters "
+	base_cycles=$(perf stat --no-big-num -e cycles -- $workload 2>&1 | awk '/cycles/ {print $1}')
+	bpf_cycles=$(perf stat --no-big-num --bpf-counters -e cycles -- $workload  2>&1 | awk '/cycles/ {print $1}')
+	check_counts $base_cycles $bpf_cycles
+	compare_number $base_cycles $bpf_cycles
+	echo "[Success]"
+}
+
+test_bpf_modifier()
+{
+	printf "Testing bpf event modifier "
+	stat_output=$(perf stat --no-big-num -e cycles/name=base_cycles/,cycles/name=bpf_cycles/b -- $workload 2>&1)
+	base_cycles=$(echo "$stat_output"| awk '/base_cycles/ {print $1}')
+	bpf_cycles=$(echo "$stat_output"| awk '/bpf_cycles/ {print $1}')
+	check_counts $base_cycles $bpf_cycles
+	compare_number $base_cycles $bpf_cycles
+	echo "[Success]"
 }
 
 # skip if --bpf-counters is not supported
@@ -30,16 +68,7 @@ if ! perf stat -e cycles --bpf-counters true > /dev/null 2>&1; then
 	exit 2
 fi
 
-base_cycles=$(perf stat --no-big-num -e cycles -- perf bench sched messaging -g 1 -l 100 -t 2>&1 | awk '/cycles/ {print $1}')
-if [ "$base_cycles" = "<not" ]; then
-	echo "Skipping: cycles event not counted"
-	exit 2
-fi
-bpf_cycles=$(perf stat --no-big-num --bpf-counters -e cycles -- perf bench sched messaging -g 1 -l 100 -t 2>&1 | awk '/cycles/ {print $1}')
-if [ "$bpf_cycles" = "<not" ]; then
-	echo "Failed: cycles not counted with --bpf-counters"
-	exit 1
-fi
+test_bpf_counters
+test_bpf_modifier
 
-compare_number $base_cycles $bpf_cycles
 exit 0