Performance regression 3.10b1: inlining issue in the big _PyEval_EvalFrameDefault() function with Visual Studio (MSC)

[neonene]

BPO	45116
Nosy	@malemburg, @gvanrossum, @rhettinger, @pfmoore, @vstinner, @tjguk, @markshannon, @zware, @zooba, @animalize, @pablogsal, @brandtbucher, @neonene, @erlend-aasland, @Fidget-Spinner
PRs	bpo-45116: Add the Py_ALWAYS_INLINE macro #28390 bpo-45116: Py_DEBUG ignores Py_ALWAYS_INLINE #28419 bpo-45116: Use Py_ALWAYS_INLINE in object.h #28427 [3.10] bpo-45116: Shrink interpreter by targetted revert of #25244 #28475 bpo-45116 Fix another performance regression on Windows #28630 bpo-45116 Add a warm-up for PGO training on Windows #28631 bpo-45116: Make --inlinestat option available in build.bat for diagnostic logs #31436 [3.10] bpo-45116: Fix inlining regressions on Windows Release build #31459 gh-89279: In ceval.c, redefine some macros for speed #32387
Files	310rc1_confirm_overhead.patch ceval_310rc1_patched.c b98e-no-inline-in-all.diff b98e-no-inline-in-eval.diff b98e-no-inline-in-the-others.diff pyproject_inlinestat.patch x64_28d2.log x64_b98e.log 310rc2_benchmarks.txt 310a7_vs_310rc2_bench.txt PR28475_inline.log PR28475_vs_310rc2_vs_310a7.txt PR28475_skip1test_bench.txt 310rc2patched_vs_310rc2notrace.txt switch-case_unarranged_bench.txt ceval_PR29565_split_func.c

^{Note: these values reflect the state of the issue at the time it was migrated and might not reflect the current state.}

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GitHub fields:

assignee = None
closed_at = None
created_at = <Date 2021-09-06.15:27:18.216>
labels = ['interpreter-core', '3.10', 'performance', 'expert-C-API', '3.11', 'OS-windows']
title = 'Performance regression 3.10b1: inlining issue in the big _PyEval_EvalFrameDefault() function with Visual Studio (MSC)'
updated_at = <Date 2022-04-08.11:04:12.476>
user = 'https://github.com/neonene'

bugs.python.org fields:

activity = <Date 2022-04-08.11:04:12.476>
actor = 'steve.dower'
assignee = 'none'
closed = False
closed_date = None
closer = None
components = ['Interpreter Core', 'Windows', 'C API']
creation = <Date 2021-09-06.15:27:18.216>
creator = 'neonene'
dependencies = []
files = ['50263', '50264', '50271', '50272', '50273', '50274', '50275', '50276', '50280', '50286', '50291', '50293', '50296', '50315', '50363', '50452']
hgrepos = []
issue_num = 45116
keywords = ['patch']
message_count = 82.0
messages = ['401143', '401152', '401154', '401182', '401183', '401319', '401329', '401346', '401364', '401623', '401624', '401628', '401743', '401964', '401970', '401972', '402025', '402040', '402043', '402044', '402063', '402064', '402065', '402067', '402068', '402071', '402090', '402091', '402092', '402098', '402099', '402117', '402135', '402143', '402189', '402190', '402217', '402229', '402230', '402287', '402289', '402296', '402307', '402308', '402320', '402480', '402856', '402857', '402858', '402864', '402867', '402871', '402878', '402886', '402891', '402893', '402928', '402930', '402954', '403403', '403409', '403430', '403432', '403464', '403559', '403587', '403609', '404089', '406354', '406386', '406407', '406416', '406471', '406474', '406479', '406487', '406613', '407188', '415378', '416911', '416950', '416977']
nosy_count = 15.0
nosy_names = ['lemburg', 'gvanrossum', 'rhettinger', 'paul.moore', 'vstinner', 'tim.golden', 'Mark.Shannon', 'zach.ware', 'steve.dower', 'malin', 'pablogsal', 'brandtbucher', 'neonene', 'erlendaasland', 'kj']
pr_nums = ['28390', '28419', '28427', '28475', '28630', '28631', '31436', '31459', '32387']
priority = None
resolution = None
stage = 'patch review'
status = 'open'
superseder = None
type = 'performance'
url = 'https://bugs.python.org/issue45116'
versions = ['Python 3.10', 'Python 3.11']

[neonene]

pyperformance on Windows shows some gap between 3.10a7 and 3.10b1.
The following are the ratios compared with 3.10a7 (the higher the slower).

-------------------------------------------------
Windows x64 | PGO release official-binary
----------------+--------------------------------
20210405 |
3.10a7 | 1.00 1.24 1.00 (PGO?)
20210408-07:58 |
b98eba5 | 0.98
20210408-10:22 |

• PR25244 | 1.04
  20210503 |
  3.10b1 | 1.07 1.21 1.07
  -------------------------------------------------
  Windows x86 | PGO release official-binary
  ----------------+--------------------------------
  20210405 |
  3.10a7 | 1.00 1.25 1.27 (release?)
  20210408-07:58 |
  b98eba5 | 1.00
  20210408-10:22 |
• PR25244 | 1.11
  20210503 |
  3.10b1 | 1.14 1.28 1.29

Since PR25244 (28d28e0),
_PyEval_EvalFrameDefault() in ceval.c has seemed to be unoptimized with PGO (msvc14.29.16.10).
At least the functions below have become un-inlined there at all.

(1) _Py_DECREF() (from Py_DECREF,Py_CLEAR,Py_SETREF)
(2) _Py_XDECREF() (from Py_XDECREF,SETLOCAL)
(3) _Py_IS_TYPE() (from PyXXX_CheckExact)
(4) _Py_atomic_load_32bit_impl() (from CHECK_EVAL_BREAKER)

I tried in vain other linker options like thread-safe-profiling, agressive-code-generation, /OPT:NOREF.
3.10a7 can inline them in the eval-loop even if profiling only test_array.py.

I measured overheads of (1)~(4) on my own build whose eval-loop uses macros instead of them.

-----------------------------------------------------------------
Windows x64 | PGO patched overhead in eval-loop
----------------+------------------------------------------------
3.10a7 | 1.00
20210802 |
3.10rc1 | 1.09 1.05 4% (slow 43, fast 5, same 10)
20210831-20:42 |
863154c | 0.95 0.90 5% (slow 48, fast 3, same 7)
(3.11a0+) |
-----------------------------------------------------------------
Windows x86 | PGO patched overhead in eval-loop
----------------+------------------------------------------------
3.10a7 | 1.00
20210802 |
3.10rc1 | 1.15 1.13 2% (slow 29, fast 14, same 15)
20210831-20:42 |
863154c | 1.05 1.02 3% (slow 44, fast 7, same 7)
(3.11a0+) |

[vstinner]

Rather than defining again functions as macro, you should consider using __forceinline function attribute: see bpo-45094.

[rhettinger]

Perhaps these critical code sections should have been left as macros. It is difficult to assuring system wide inlining across modules.