[PATCH 2/2] perf test: Add python JIT dump test

[Namhyung Kim <namhyung@kernel.org>]

Add a test case for the python interpreter like below so that we can
make sure it won't break again.  To validate the effect of build-ID
generation, it adds and removes the JIT'ed DSOs to/from the build-ID
cache for the test.

  $ perf test -vv jitdump
   84: python profiling with jitdump:
  --- start ---
  test child forked, pid 214316
  Run python with -Xperf_jit
  [ perf record: Woken up 5 times to write data ]
  [ perf record: Captured and wrote 1.180 MB /tmp/__perf_test.perf.data.XbqZNm (140 samples) ]
  Generate JIT-ed DSOs using perf inject
  Add JIT-ed DSOs to the build-ID cache
  Check the symbol containing the script name
  Found 108 matching lines
  Remove JIT-ed DSOs from the build-ID cache
  ---- end(0) ----
   84: python profiling with jitdump                                   : Ok

Cc: Pablo Galindo <pablogsal@gmail.com>
Link: https://docs.python.org/3/howto/perf_profiling.html#how-to-work-without-frame-pointers
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
---
 tools/perf/tests/shell/jitdump-python.sh | 41 ++++++++++++++++++++++++
 tools/perf/tests/shell/jitdump-test.py   | 14 ++++++++
 2 files changed, 55 insertions(+)
 create mode 100755 tools/perf/tests/shell/jitdump-python.sh
 create mode 100644 tools/perf/tests/shell/jitdump-test.py

diff --git a/tools/perf/tests/shell/jitdump-python.sh b/tools/perf/tests/shell/jitdump-python.sh
new file mode 100755
index 0000000000000000..101c15e65da1a0c0
--- /dev/null
+++ b/tools/perf/tests/shell/jitdump-python.sh
@@ -0,0 +1,41 @@
+#!/bin/bash
+# python profiling with jitdump
+# SPDX-License-Identifier: GPL-2.0
+
+if ! command -v python > /dev/null; then
+    echo "Skip: no python found"
+    exit 2
+fi
+
+SHELLDIR=$(dirname $0)
+PERF_DATA=$(mktemp /tmp/__perf_test.perf.data.XXXXXX)
+
+echo "Run python with -Xperf_jit"
+perf record -k 1 -g --call-graph dwarf -o "${PERF_DATA}" -- python -Xperf_jit ${SHELLDIR}/jitdump-test.py
+
+_PID=$(perf report -i "${PERF_DATA}" -F pid -q -g none | cut -d: -f1 -s)
+PID=$(echo -n $_PID)  # remove newlines
+
+echo "Generate JIT-ed DSOs using perf inject"
+perf inject -i "${PERF_DATA}" -j -o "${PERF_DATA}.jit"
+
+echo "Add JIT-ed DSOs to the build-ID cache"
+for F in /tmp/jitted-${PID}-*.so; do
+  perf buildid-cache -a "${F}"
+done
+
+echo "Check the symbol containing the script name"
+NUM=$(perf report -i "${PERF_DATA}.jit" -s sym | grep -c jitdump-test.py)
+
+echo "Found ${NUM} matching lines"
+
+echo "Remove JIT-ed DSOs from the build-ID cache"
+for F in /tmp/jitted-${PID}-*.so; do
+  perf buildid-cache -r "${F}"
+done
+
+rm -f ${PERF_DATA} ${PERF_DATA}.jit /tmp/jit-${PID}.dump /tmp/jitted-${PID}-*.so
+
+if [ "${NUM}" -eq 0 ]; then
+    exit 1
+fi
diff --git a/tools/perf/tests/shell/jitdump-test.py b/tools/perf/tests/shell/jitdump-test.py
new file mode 100644
index 0000000000000000..b427363ae4956db6
--- /dev/null
+++ b/tools/perf/tests/shell/jitdump-test.py
@@ -0,0 +1,14 @@
+def foo(n):
+    result = 0
+    for _ in range(n):
+        result += 1
+    return result
+
+def bar(n):
+    foo(n)
+
+def baz(n):
+    bar(n)
+
+if __name__ == "__main__":
+    baz(1000000)
-- 
2.52.0.rc1.455.g30608eb744-goog