Add leader sampling test to validate event counts are captured into
record and the count value is consistent.

Suggested-by: Kan Liang <kan.liang@linux.intel.com>
Reviewed-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Dapeng Mi <dapeng1.mi@linux.intel.com>
---
 tools/perf/tests/shell/record.sh | 28 ++++++++++++++++++++++++++++
 1 file changed, 28 insertions(+)

diff --git a/tools/perf/tests/shell/record.sh b/tools/perf/tests/shell/record.sh
index 048078ee2eca..45baf7910640 100755
--- a/tools/perf/tests/shell/record.sh
+++ b/tools/perf/tests/shell/record.sh
@@ -17,6 +17,7 @@ skip_test_missing_symbol ${testsym}
 
 err=0
 perfdata=$(mktemp /tmp/__perf_test.perf.data.XXXXX)
+script_output=$(mktemp /tmp/__perf_test.perf.data.XXXXX.script)
 testprog="perf test -w thloop"
 cpu_pmu_dir="/sys/bus/event_source/devices/cpu*"
 br_cntr_file="/caps/branch_counter_nr"
@@ -228,6 +229,32 @@ test_cgroup() {
   echo "Cgroup sampling test [Success]"
 }
 
+test_leader_sampling() {
+  echo "Basic leader sampling test"
+  if ! perf record -o "${perfdata}" -e "{branches,branches}:Su" perf test -w brstack 2> /dev/null
+  then
+    echo "Leader sampling [Failed record]"
+    err=1
+    return
+  fi
+  index=0
+  perf script -i "${perfdata}" > $script_output
+  while IFS= read -r line
+  do
+    # Check if the two branches counts are equal in each record
+    branches=$(echo $line | awk '{for(i=1;i<=NF;i++) if($i=="branches:") print $(i-1)}')
+    if [ $(($index%2)) -ne 0 ] && [ ${branches}x != ${prev_branches}x ]
+    then
+      echo "Leader sampling [Failed inconsistent branches count]"
+      err=1
+      return
+    fi
+    index=$(($index+1))
+    prev_branches=$branches
+  done < $script_output
+  echo "Basic leader sampling test [Success]"
+}
+
 # raise the limit of file descriptors to minimum
 if [[ $default_fd_limit -lt $min_fd_limit ]]; then
        ulimit -Sn $min_fd_limit
@@ -239,6 +266,7 @@ test_system_wide
 test_workload
 test_branch_counter
 test_cgroup
+test_leader_sampling
 
 # restore the default value
 ulimit -Sn $default_fd_limit
-- 
2.40.1