fixup! Allow perf to work without frame pointers

Author: pablogsal

Lib/test/test_perf_profiler.py

@@ -383,6 +383,29 @@ def baz(n):
  self.assertNotIn(f"py::bar:{script}", stdout)
  self.assertNotIn(f"py::baz:{script}", stdout)
 
+@unittest.skipUnless(perf_command_works(), "perf command doesn't work")
+@unittest.skipUnless(
+ is_unwinding_reliable_with_frame_pointers(),
+ "Unwinding is unreliable with frame pointers",
+)
+class TestPerfProfiler(unittest.TestCase, TestPerfProfilerMixin):
+ def run_perf(self, script_dir, script, activate_trampoline=True):
+ if activate_trampoline:
+ return run_perf(script_dir, sys.executable, "-Xperf", script)
+ return run_perf(script_dir, sys.executable, script)
+
+ def setUp(self):
+ super().setUp()
+ self.perf_files = set(pathlib.Path("/tmp/").glob("perf-*.map"))
+
+ def tearDown(self) -> None:
+ super().tearDown()
+ files_to_delete = (
+ set(pathlib.Path("/tmp/").glob("perf-*.map")) - self.perf_files
+ )
+ for file in files_to_delete:
+ file.unlink()
+
  def test_pre_fork_compile(self):
  code = """if 1:
  import sys
@@ -400,7 +423,7 @@ def bar_fork():
  foo_fork()
 
  def foo():
- pass
+ import time; time.sleep(1)
 
  def bar():
  foo()
@@ -457,30 +480,6 @@ def compile_trampolines_for_all_functions():
  self.assertIn(line, child_perf_file_contents)
 
 
-@unittest.skipUnless(perf_command_works(), "perf command doesn't work")
-@unittest.skipUnless(
- is_unwinding_reliable_with_frame_pointers(),
- "Unwinding is unreliable with frame pointers",
-)
-class TestPerfProfiler(unittest.TestCase, TestPerfProfilerMixin):
- def run_perf(self, script_dir, script, activate_trampoline=True):
- if activate_trampoline:
- return run_perf(script_dir, sys.executable, "-Xperf", script)
- return run_perf(script_dir, sys.executable, script)
-
- def setUp(self):
- super().setUp()
- self.perf_files = set(pathlib.Path("/tmp/").glob("perf-*.map"))
-
- def tearDown(self) -> None:
- super().tearDown()
- files_to_delete = (
- set(pathlib.Path("/tmp/").glob("perf-*.map")) - self.perf_files
- )
- for file in files_to_delete:
- file.unlink()
-
-
 @unittest.skipUnless(perf_command_works(), "perf command doesn't work")
 class TestPerfProfilerWithDwarf(unittest.TestCase, TestPerfProfilerMixin):
  def run_perf(self, script_dir, script, activate_trampoline=True):

Python/perf_trampoline.c

@@ -318,6 +318,7 @@ static int perf_map_fini(void* state) {
  // clean up the lock and state
  PyThread_free_lock(perf_map_state.map_lock);
  perf_map_state.perf_map = NULL;
+ trampoline_api.state = NULL;
  }
  return 0;
 }
@@ -655,6 +656,7 @@ static int perf_map_jit_fini(void* state) {
  if (perf_jit_map_state.mapped_buffer != NULL) {
  munmap(perf_jit_map_state.mapped_buffer, perf_jit_map_state.mapped_size);
  }
+ trampoline_api.state = NULL;
  return 0;
 }
 
@@ -807,6 +809,9 @@ py_trampoline_evaluator(PyThreadState *ts, _PyInterpreterFrame *frame,
 int PyUnstable_PerfTrampoline_CompileCode(PyCodeObject *co)
 {
 #ifdef PY_HAVE_PERF_TRAMPOLINE
+ if (perf_status != PERF_STATUS_OK) {
+ return -1;
+ }
  py_trampoline f = NULL;
  assert(extra_code_index != -1);
  int ret = _PyCode_GetExtra((PyObject *)co, extra_code_index, (void **)&f);
@@ -911,6 +916,16 @@ _PyPerfTrampoline_Init(int activate)
  perf_status = PERF_STATUS_OK;
  }
 
+ if (trampoline_api.init_state) {
+ trampoline_api.state = trampoline_api.init_state();
+ if (trampoline_api.state == NULL) {
+ return -1;
+ }
+ }
+ else {
+ trampoline_api.state = NULL;
+ }
+
 #endif
  return 0;
 }
@@ -947,15 +962,17 @@ _PyPerfTrampoline_AfterFork_Child(void)
  char filename[256];
  pid_t parent_pid = getppid();
  snprintf(filename, sizeof(filename), "/tmp/perf-%d.map", parent_pid);
- if (PyUnstable_CopyPerfMapFile(filename) != 0) {
+ if ( PyUnstable_CopyPerfMapFile(filename) != 0) {
  return PyStatus_Error("Failed to copy perf map file.");
  }
  } else {
+ PyUnstable_PerfMapState_Fini();
  // Restart trampoline in file in child.
  int was_active = _PyIsPerfTrampolineActive();
  _PyPerfTrampoline_Fini();
  if (was_active) {
  _PyPerfTrampoline_Init(1);
+ trampoline_api.init_state();
  }
  }
 #endif

Python/sysmodule.c

@@ -2379,13 +2379,10 @@ PyAPI_FUNC(void) PyUnstable_PerfMapState_Fini(void) {
 
 PyAPI_FUNC(int) PyUnstable_CopyPerfMapFile(const char* parent_filename) {
 #ifndef MS_WINDOWS
- void *state = _PyPerfTrampoline_GetState();
- if (state) {
- _PyPerf_Callbacks cur_cb;
- _PyPerfTrampoline_GetCallbacks(&cur_cb);
- if (cur_cb.copy_file != NULL) {
- cur_cb.copy_file(parent_filename);
- }
+ _PyPerf_Callbacks cur_cb;
+ _PyPerfTrampoline_GetCallbacks(&cur_cb);
+ if (cur_cb.copy_file != NULL) {
+ cur_cb.copy_file(parent_filename);
  }
 #endif
  return 0;