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
        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