Series comparison

-[PATCH v1] perf test: Allow tolerance for leader sampling test
+[PATCH v3] perf test: Allow tolerance for leader sampling test
+V3: Added check for missing samples as suggested by Chun-Tse.
+V2: Changed bc invocation to return 0 on success and 1 on error.
 There is a known issue that the leader sampling is inconsistent, since
 throttle only affect leader, not the slave. The detail is in [1]. To
 maintain test coverage, this patch sets a tolerance rate of 80% to
 accommodate the throttled samples and prevent test failures due to
 throttling.
 ...
 Signed-off-by: Chun-Tse Shao <ctshao@google.com>
 Suggested-by: Ian Rogers <irogers@google.com>
 Suggested-by: Thomas Richter <tmricht@linux.ibm.com>
 Tested-by: Thomas Richter <tmricht@linux.ibm.com>
+Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
 ---
- tools/perf/tests/shell/record.sh | 25 +++++++++++++++++++------
+ tools/perf/tests/shell/record.sh | 33 ++++++++++++++++++++++++++------
-file changed, 19 insertions(+), 6 deletions(-)
+file changed, 27 insertions(+), 6 deletions(-)
 diff --git a/tools/perf/tests/shell/record.sh b/tools/perf/tests/shell/record.sh
 index XXXXXXX..XXXXXXX 100755
 --- a/tools/perf/tests/shell/record.sh
 +++ b/tools/perf/tests/shell/record.sh
 ...
      fi
      index=$(($index+1))
      prev_cycles=$cycles
    done < $script_output
 -  echo "Basic leader sampling test [Success]"
-+  if [[ "$(echo "scale=2; $invalid_counts/($invalid_counts+$valid_counts)" | bc)" > 1-$tolerance_rate ]]
++  total_counts=$(bc <<< "$invalid_counts+$valid_counts")
 +  if (( $(bc <<< "$total_counts <= 0") ))
 +  then
-+      echo "Leader sampling [Failed inconsistent cycles count]"
++    echo "Leader sampling [No sample generated]"
-+      err=1
++    err=1
 +    return
 +  fi
 +  isok=$(bc <<< "scale=2; if (($invalid_counts/$total_counts) < (1-$tolerance_rate)) { 0 } else { 1 };")
 +  if [ $isok -eq 1 ]
 +  then
 +     echo "Leader sampling [Failed inconsistent cycles count]"
 +     err=1
 +  else
 +    echo "Basic leader sampling test [Success]"
 +  fi
  }
  test_topdown_leader_sampling() {
 --
-.49.0.472.ge94155a9ec-goog
+.49.0

There is a known issue that the leader sampling is inconsistent, since
throttle only affect leader, not the slave. The detail is in [1]. To
maintain test coverage, this patch sets a tolerance rate of 80% to
accommodate the throttled samples and prevent test failures due to
throttling.

[1] lore.kernel.org/20250328182752.769662-1-ctshao@google.com

Signed-off-by: Chun-Tse Shao <ctshao@google.com>
Suggested-by: Ian Rogers <irogers@google.com>
Suggested-by: Thomas Richter <tmricht@linux.ibm.com>
Tested-by: Thomas Richter <tmricht@linux.ibm.com>
---
 tools/perf/tests/shell/record.sh | 25 +++++++++++++++++++------
 1 file changed, 19 insertions(+), 6 deletions(-)

diff --git a/tools/perf/tests/shell/record.sh b/tools/perf/tests/shell/record.sh
index XXXXXXX..XXXXXXX 100755
--- a/tools/perf/tests/shell/record.sh
+++ b/tools/perf/tests/shell/record.sh
@@ -XXX,XX +XXX,XX @@ test_leader_sampling() {
     err=1
     return
   fi
+  perf script -i "${perfdata}" | grep brstack > $script_output
+  # Check if the two instruction counts are equal in each record.
+  # However, the throttling code doesn't consider event grouping. During throttling, only the
+  # leader is stopped, causing the slave's counts significantly higher. To temporarily solve this,
+  # let's set the tolerance rate to 80%.
+  # TODO: Revert the code for tolerance once the throttling mechanism is fixed.
   index=0
-  perf script -i "${perfdata}" > $script_output
+  valid_counts=0
+  invalid_counts=0
+  tolerance_rate=0.8
   while IFS= read -r line
   do
-    # Check if the two instruction counts are equal in each record
     cycles=$(echo $line | awk '{for(i=1;i<=NF;i++) if($i=="cycles:") print $(i-1)}')
     if [ $(($index%2)) -ne 0 ] && [ ${cycles}x != ${prev_cycles}x ]
     then
-      echo "Leader sampling [Failed inconsistent cycles count]"
-      err=1
-      return
+      invalid_counts=$(($invalid_counts+1))
+    else
+      valid_counts=$(($valid_counts+1))
     fi
     index=$(($index+1))
     prev_cycles=$cycles
   done < $script_output
-  echo "Basic leader sampling test [Success]"
+  if [[ "$(echo "scale=2; $invalid_counts/($invalid_counts+$valid_counts)" | bc)" > 1-$tolerance_rate ]]
+  then
+      echo "Leader sampling [Failed inconsistent cycles count]"
+      err=1
+  else
+    echo "Basic leader sampling test [Success]"
+  fi
 }

test_topdown_leader_sampling() {
--
2.49.0.472.ge94155a9ec-goog

V3: Added check for missing samples as suggested by Chun-Tse.
V2: Changed bc invocation to return 0 on success and 1 on error.

[1] lore.kernel.org/20250328182752.769662-1-ctshao@google.com

Signed-off-by: Chun-Tse Shao <ctshao@google.com>
Suggested-by: Ian Rogers <irogers@google.com>
Suggested-by: Thomas Richter <tmricht@linux.ibm.com>
Tested-by: Thomas Richter <tmricht@linux.ibm.com>
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
---
 tools/perf/tests/shell/record.sh | 33 ++++++++++++++++++++++++++------
 1 file changed, 27 insertions(+), 6 deletions(-)

diff --git a/tools/perf/tests/shell/record.sh b/tools/perf/tests/shell/record.sh
index XXXXXXX..XXXXXXX 100755
--- a/tools/perf/tests/shell/record.sh
+++ b/tools/perf/tests/shell/record.sh
@@ -XXX,XX +XXX,XX @@ test_leader_sampling() {
     err=1
     return
   fi
+  perf script -i "${perfdata}" | grep brstack > $script_output
+  # Check if the two instruction counts are equal in each record.
+  # However, the throttling code doesn't consider event grouping. During throttling, only the
+  # leader is stopped, causing the slave's counts significantly higher. To temporarily solve this,
+  # let's set the tolerance rate to 80%.
+  # TODO: Revert the code for tolerance once the throttling mechanism is fixed.
   index=0
-  perf script -i "${perfdata}" > $script_output
+  valid_counts=0
+  invalid_counts=0
+  tolerance_rate=0.8
   while IFS= read -r line
   do
-    # Check if the two instruction counts are equal in each record
     cycles=$(echo $line | awk '{for(i=1;i<=NF;i++) if($i=="cycles:") print $(i-1)}')
     if [ $(($index%2)) -ne 0 ] && [ ${cycles}x != ${prev_cycles}x ]
     then
-      echo "Leader sampling [Failed inconsistent cycles count]"
-      err=1
-      return
+      invalid_counts=$(($invalid_counts+1))
+    else
+      valid_counts=$(($valid_counts+1))
     fi
     index=$(($index+1))
     prev_cycles=$cycles
   done < $script_output
-  echo "Basic leader sampling test [Success]"
+  total_counts=$(bc <<< "$invalid_counts+$valid_counts")
+  if (( $(bc <<< "$total_counts <= 0") ))
+  then
+    echo "Leader sampling [No sample generated]"
+    err=1
+    return
+  fi
+  isok=$(bc <<< "scale=2; if (($invalid_counts/$total_counts) < (1-$tolerance_rate)) { 0 } else { 1 };")
+  if [ $isok -eq 1 ]
+  then
+     echo "Leader sampling [Failed inconsistent cycles count]"
+     err=1
+  else
+    echo "Basic leader sampling test [Success]"
+  fi
 }
 
 test_topdown_leader_sampling() {
-- 
2.49.0