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gh-137291: Support perf profiler with an evaluation hook (#137292)

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Support perf profiler with an evaluation hook
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Dino Viehland 2025-08-07 14:54:12 -07:00 • committed by GitHub
parent e3ad9003c5
commit 375f484f97
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GPG key ID: B5690EEEBB952194
4 changed files with 54 additions and 47 deletions
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1
Include/internal/pycore_interp_structs.h
View file

@ -88,6 +88,7 @@ struct _ceval_runtime_state {
struct trampoline_api_st trampoline_api;
FILE *map_file;
Py_ssize_t persist_after_fork;
_PyFrameEvalFunction prev_eval_frame;
#else
int _not_used;
#endif

81
Lib/test/test_perf_profiler.py
View file

@ -162,48 +162,55 @@ class TestPerfTrampoline(unittest.TestCase):
@unittest.skipIf(support.check_bolt_optimized(), "fails on BOLT instrumented binaries")
def test_sys_api(self):
code = """if 1:
import sys
def foo():
pass
for define_eval_hook in (False, True):
code = """if 1:
import sys
def foo():
pass
def spam():
pass
def spam():
pass
def bar():
sys.deactivate_stack_trampoline()
foo()
sys.activate_stack_trampoline("perf")
spam()
def baz():
bar()
def bar():
sys.deactivate_stack_trampoline()
foo()
sys.activate_stack_trampoline("perf")
spam()
baz()
"""
if define_eval_hook:
set_eval_hook = """if 1:
import _testinternalcapi
_testinternalcapi.set_eval_frame_record([])
"""
code = set_eval_hook + code
with temp_dir() as script_dir:
script = make_script(script_dir, "perftest", code)
env = {**os.environ, "PYTHON_JIT": "0"}
with subprocess.Popen(
[sys.executable, script],
text=True,
stderr=subprocess.PIPE,
stdout=subprocess.PIPE,
env=env,
) as process:
stdout, stderr = process.communicate()
def baz():
bar()
self.assertEqual(stderr, "")
self.assertEqual(stdout, "")
sys.activate_stack_trampoline("perf")
baz()
"""
with temp_dir() as script_dir:
script = make_script(script_dir, "perftest", code)
env = {**os.environ, "PYTHON_JIT": "0"}
with subprocess.Popen(
[sys.executable, script],
text=True,
stderr=subprocess.PIPE,
stdout=subprocess.PIPE,
env=env,
) as process:
stdout, stderr = process.communicate()
self.assertEqual(stderr, "")
self.assertEqual(stdout, "")
perf_file = pathlib.Path(f"/tmp/perf-{process.pid}.map")
self.assertTrue(perf_file.exists())
perf_file_contents = perf_file.read_text()
self.assertNotIn(f"py::foo:{script}", perf_file_contents)
self.assertIn(f"py::spam:{script}", perf_file_contents)
self.assertIn(f"py::bar:{script}", perf_file_contents)
self.assertIn(f"py::baz:{script}", perf_file_contents)
perf_file = pathlib.Path(f"/tmp/perf-{process.pid}.map")
self.assertTrue(perf_file.exists())
perf_file_contents = perf_file.read_text()
self.assertNotIn(f"py::foo:{script}", perf_file_contents)
self.assertIn(f"py::spam:{script}", perf_file_contents)
self.assertIn(f"py::bar:{script}", perf_file_contents)
self.assertIn(f"py::baz:{script}", perf_file_contents)
def test_sys_api_with_existing_trampoline(self):
code = """if 1:

1
Misc/NEWS.d/next/Core_and_Builtins/2025-07-31-23-02-02.gh-issue-137291.kIxVZd.rst Normal file
View file

@ -0,0 +1 @@
The perf profiler can now be used if a previous frame evaluation API has been provided.

18
Python/perf_trampoline.c
View file

@ -202,6 +202,7 @@ enum perf_trampoline_type {
#define perf_map_file _PyRuntime.ceval.perf.map_file
#define persist_after_fork _PyRuntime.ceval.perf.persist_after_fork
#define perf_trampoline_type _PyRuntime.ceval.perf.perf_trampoline_type
#define prev_eval_frame _PyRuntime.ceval.perf.prev_eval_frame
static void
perf_map_write_entry(void *state, const void *code_addr,
@ -407,9 +408,12 @@ py_trampoline_evaluator(PyThreadState *ts, _PyInterpreterFrame *frame,
f = new_trampoline;
}
assert(f != NULL);
return f(ts, frame, throw, _PyEval_EvalFrameDefault);
return f(ts, frame, throw, prev_eval_frame != NULL ? prev_eval_frame : _PyEval_EvalFrameDefault);
default_eval:
// Something failed, fall back to the default evaluator.
if (prev_eval_frame) {
return prev_eval_frame(ts, frame, throw);
}
return _PyEval_EvalFrameDefault(ts, frame, throw);
}
#endif // PY_HAVE_PERF_TRAMPOLINE
@ -481,18 +485,12 @@ _PyPerfTrampoline_Init(int activate)
{
#ifdef PY_HAVE_PERF_TRAMPOLINE
PyThreadState *tstate = _PyThreadState_GET();
if (tstate->interp->eval_frame &&
tstate->interp->eval_frame != py_trampoline_evaluator) {
PyErr_SetString(PyExc_RuntimeError,
"Trampoline cannot be initialized as a custom eval "
"frame is already present");
return -1;
}
if (!activate) {
_PyInterpreterState_SetEvalFrameFunc(tstate->interp, NULL);
_PyInterpreterState_SetEvalFrameFunc(tstate->interp, prev_eval_frame);
perf_status = PERF_STATUS_NO_INIT;
}
else {
else if (tstate->interp->eval_frame != py_trampoline_evaluator) {
prev_eval_frame = _PyInterpreterState_GetEvalFrameFunc(tstate->interp);
_PyInterpreterState_SetEvalFrameFunc(tstate->interp, py_trampoline_evaluator);
extra_code_index = _PyEval_RequestCodeExtraIndex(NULL);
if (extra_code_index == -1) {