classification
Title: test_concurrent_futures: reap_children() warnings on RHEL7 and RHEL8 buildbots
Type: Stage:
Components: Tests Versions: Python 3.9
process
Status: open Resolution:
Dependencies: Superseder:
Assigned To: Nosy List: pablogsal, vstinner
Priority: normal Keywords:

Created on 2019-10-21 11:20 by vstinner, last changed 2019-12-06 17:38 by vstinner.

Messages (9)
msg355051 - (view) Author: STINNER Victor (vstinner) * (Python committer) Date: 2019-10-21 11:20
https://buildbot.python.org/all/#/builders/254/builds/162

test_no_stale_references (test.test_concurrent_futures.ProcessPoolSpawnProcessPoolExecutorTest) ... 0.56s ok
test_ressources_gced_in_workers (test.test_concurrent_futures.ProcessPoolSpawnProcessPoolExecutorTest) ... 1.90s ok
test_shutdown_race_issue12456 (test.test_concurrent_futures.ProcessPoolSpawnProcessPoolExecutorTest) ... 0.54s ok
test_submit (test.test_concurrent_futures.ProcessPoolSpawnProcessPoolExecutorTest) ... 0.52s ok
test_submit_keyword (test.test_concurrent_futures.ProcessPoolSpawnProcessPoolExecutorTest) ... 0.57s ok
test_traceback (test.test_concurrent_futures.ProcessPoolSpawnProcessPoolExecutorTest) ... 0.48s ok
test_context_manager_shutdown (test.test_concurrent_futures.ProcessPoolSpawnProcessPoolShutdownTest) ... 0.03s ok
test_del_shutdown (test.test_concurrent_futures.ProcessPoolSpawnProcessPoolShutdownTest) ... 0.02s ok
test_hang_issue12364 (test.test_concurrent_futures.ProcessPoolSpawnProcessPoolShutdownTest) ... 1.45s ok
test_interpreter_shutdown (test.test_concurrent_futures.ProcessPoolSpawnProcessPoolShutdownTest) ... 1.62s Warning -- reap_children() reaped child process 28936
ok
msg355053 - (view) Author: STINNER Victor (vstinner) * (Python committer) Date: 2019-10-21 11:20
It looks similar to bpo-38448: "test_concurrent_futures: reap_children() reaped child process 26487 on AMD64 RHEL8 Refleaks 3.x"
msg355079 - (view) Author: STINNER Victor (vstinner) * (Python committer) Date: 2019-10-21 15:47
I ran "./python -m test --fail-env-changed -w -j50 -F test_concurrent_futures" on my laptop for 5 minutes: system load of 220,57 with a peak of 403 processes... but I failed to reproduce the issue :-(
msg355107 - (view) Author: STINNER Victor (vstinner) * (Python committer) Date: 2019-10-21 22:33
The system load was at 10.02 when the bug occurred:

> https://buildbot.python.org/all/#/builders/254/builds/162

...
0:04:11 load avg: 10.02 [230/419] test_pkgutil passed -- running: test_io (2 min 46 sec), test_capi (1 min 12 sec), test_concurrent_futures (2 min 43 sec), test_mailbox (2 min 40 sec), test_tokenize (30.6 sec)
0:04:12 load avg: 10.02 [231/419] test_getpass passed -- running: test_io (2 min 47 sec), test_capi (1 min 13 sec), test_concurrent_futures (2 min 43 sec), test_mailbox (2 min 41 sec), test_tokenize (31.1 sec)
0:04:12 load avg: 10.02 [232/419] test_sys passed -- running: test_io (2 min 47 sec), test_capi (1 min 13 sec), test_concurrent_futures (2 min 43 sec), test_mailbox (2 min 41 sec), test_tokenize (31.3 sec)
0:04:12 load avg: 10.02 [233/419] test_winconsoleio skipped -- running: test_io (2 min 48 sec), test_capi (1 min 13 sec), test_concurrent_futures (2 min 44 sec), test_mailbox (2 min 41 sec), test_tokenize (31.7 sec)
test_winconsoleio skipped -- test only relevant on win32
0:04:13 load avg: 10.02 [234/419/1] test_concurrent_futures failed (env changed) (2 min 44 sec) -- running: test_io (2 min 48 sec), test_capi (1 min 14 sec), test_mailbox (2 min 42 sec), test_tokenize (32.0 sec)
...
test_crash (test.test_concurrent_futures.ProcessPoolSpawnExecutorDeadlockTest) ... 4.22s ok
test_shutdown_deadlock (test.test_concurrent_futures.ProcessPoolSpawnExecutorDeadlockTest) ... 1.03s ok
test_initializer (test.test_concurrent_futures.ProcessPoolSpawnFailingInitializerTest) ... 0.51s ok
test_initializer (test.test_concurrent_futures.ProcessPoolSpawnInitializerTest) ... 0.54s ok
test_free_reference (test.test_concurrent_futures.ProcessPoolSpawnProcessPoolExecutorTest) ... 0.67s ok
test_killed_child (test.test_concurrent_futures.ProcessPoolSpawnProcessPoolExecutorTest) ... 0.49s ok
test_map (test.test_concurrent_futures.ProcessPoolSpawnProcessPoolExecutorTest) ... 0.56s ok
test_map_chunksize (test.test_concurrent_futures.ProcessPoolSpawnProcessPoolExecutorTest) ... 0.46s ok
test_map_exception (test.test_concurrent_futures.ProcessPoolSpawnProcessPoolExecutorTest) ... 0.46s ok
test_map_timeout (test.test_concurrent_futures.ProcessPoolSpawnProcessPoolExecutorTest) ... 6.48s ok
test_max_workers_negative (test.test_concurrent_futures.ProcessPoolSpawnProcessPoolExecutorTest) ... 0.57s ok
test_max_workers_too_large (test.test_concurrent_futures.ProcessPoolSpawnProcessPoolExecutorTest) ... skipped 'Windows-only process limit'
test_no_stale_references (test.test_concurrent_futures.ProcessPoolSpawnProcessPoolExecutorTest) ... 0.56s ok
test_ressources_gced_in_workers (test.test_concurrent_futures.ProcessPoolSpawnProcessPoolExecutorTest) ... 1.90s ok
test_shutdown_race_issue12456 (test.test_concurrent_futures.ProcessPoolSpawnProcessPoolExecutorTest) ... 0.54s ok
test_submit (test.test_concurrent_futures.ProcessPoolSpawnProcessPoolExecutorTest) ... 0.52s ok
test_submit_keyword (test.test_concurrent_futures.ProcessPoolSpawnProcessPoolExecutorTest) ... 0.57s ok
test_traceback (test.test_concurrent_futures.ProcessPoolSpawnProcessPoolExecutorTest) ... 0.48s ok
test_context_manager_shutdown (test.test_concurrent_futures.ProcessPoolSpawnProcessPoolShutdownTest) ... 0.03s ok
test_del_shutdown (test.test_concurrent_futures.ProcessPoolSpawnProcessPoolShutdownTest) ... 0.02s ok
test_hang_issue12364 (test.test_concurrent_futures.ProcessPoolSpawnProcessPoolShutdownTest) ... 1.45s ok
test_interpreter_shutdown (test.test_concurrent_futures.ProcessPoolSpawnProcessPoolShutdownTest) ... 1.62s 
Warning -- reap_children() reaped child process 28936
ok
test_processes_terminate (test.test_concurrent_futures.ProcessPoolSpawnProcessPoolShutdownTest) ... 0.47s ok
test_run_after_shutdown (test.test_concurrent_futures.ProcessPoolSpawnProcessPoolShutdownTest) ... 0.00s ok
msg355310 - (view) Author: STINNER Victor (vstinner) * (Python committer) Date: 2019-10-24 09:18
New warning on AMD64 RHEL8 LTO + PGO 3.x:
https://buildbot.python.org/all/#/builders/284/builds/171

...
test_killed_child (test.test_concurrent_futures.ProcessPoolSpawnProcessPoolExecutorTest) ... 0.26s ok
test_map (test.test_concurrent_futures.ProcessPoolSpawnProcessPoolExecutorTest) ... 0.29s ok
test_map_chunksize (test.test_concurrent_futures.ProcessPoolSpawnProcessPoolExecutorTest) ... 0.31s ok
test_map_exception (test.test_concurrent_futures.ProcessPoolSpawnProcessPoolExecutorTest) ... 0.30s ok
test_map_timeout (test.test_concurrent_futures.ProcessPoolSpawnProcessPoolExecutorTest) ... 6.29s ok
test_max_workers_negative (test.test_concurrent_futures.ProcessPoolSpawnProcessPoolExecutorTest) ... 0.32s ok
test_max_workers_too_large (test.test_concurrent_futures.ProcessPoolSpawnProcessPoolExecutorTest) ... skipped 'Windows-only process limit'
test_no_stale_references (test.test_concurrent_futures.ProcessPoolSpawnProcessPoolExecutorTest) ... 0.29s ok
test_ressources_gced_in_workers (test.test_concurrent_futures.ProcessPoolSpawnProcessPoolExecutorTest) ... 1.58s ok
test_shutdown_race_issue12456 (test.test_concurrent_futures.ProcessPoolSpawnProcessPoolExecutorTest) ... 0.30s Warning -- reap_children() reaped child process 10340
ok
test_submit (test.test_concurrent_futures.ProcessPoolSpawnProcessPoolExecutorTest) ... 0.29s ok
test_submit_keyword (test.test_concurrent_futures.ProcessPoolSpawnProcessPoolExecutorTest) ... 0.31s ok
...
msg355312 - (view) Author: STINNER Victor (vstinner) * (Python committer) Date: 2019-10-24 09:19
I closed bpo-38448 as duplicate of this issue. Copy of its only message:

AMD64 RHEL8 Refleaks 3.x:
https://buildbot.python.org/all/#/builders/272/builds/23

0:27:13 load avg: 4.88 [416/419/1] test_concurrent_futures failed (env changed) (17 min 11 sec) -- running: test_capi (7 min 28 sec), test_gdb (8 min 49 sec), test_asyncio (23 min 23 sec)
beginning 6 repetitions
123456
.Warning -- reap_children() reaped child process 26487
.....
Warning -- multiprocessing.process._dangling was modified by test_concurrent_futures
  Before: set()
  After:  {<weakref at 0x7fdc08f44e30; to 'SpawnProcess' at 0x7fdc0a467c30>}
msg357095 - (view) Author: STINNER Victor (vstinner) * (Python committer) Date: 2019-11-20 18:23
AMD64 Debian PGO 3.x:
https://buildbot.python.org/all/#/builders/47/builds/3851

test_submit_keyword (test.test_concurrent_futures.ProcessPoolSpawnProcessPoolExecutorTest) ... 0.62s Warning -- reap_children() reaped child process 32627
Warning -- multiprocessing.process._dangling was modified by test_concurrent_futures
msg357404 - (view) Author: Pablo Galindo Salgado (pablogsal) * (Python committer) Date: 2019-11-24 17:58
Ran 168 tests in 160.415s
OK (skipped=3)
Warning -- multiprocessing.process._dangling was modified by test_concurrent_futures
  Before: set()
  After:  {<weakref at 0x7fd136d66540; to 'ForkProcess' at 0x7fd136cd4a90>}

Another failure in AMD64 RHEL8 LTO + PGO 3.x

https://buildbot.python.org/all/#/builders/284/builds/300/steps/5/logs/stdio
msg357929 - (view) Author: STINNER Victor (vstinner) * (Python committer) Date: 2019-12-06 17:38
New failure on AMD64 RHEL7 LTO 3.x:
https://buildbot.python.org/all/#/builders/103/builds/17

test_interpreter_shutdown
(test.test_concurrent_futures.ProcessPoolSpawnProcessPoolShutdownTest)
... 1.61s Warning -- reap_children() reaped child process 9934
History
Date User Action Args
2019-12-06 17:38:16vstinnersetmessages: + msg357929
2019-11-24 17:58:51pablogsalsetnosy: + pablogsal
messages: + msg357404
2019-11-20 18:23:00vstinnersetmessages: + msg357095
2019-10-24 09:19:40vstinnersetmessages: + msg355312
title: test_concurrent_futures: test_interpreter_shutdown() warning "reap_children() reaped child process" on AMD64 RHEL7 3.x -> test_concurrent_futures: reap_children() warnings on RHEL7 and RHEL8 buildbots
2019-10-24 09:18:56vstinnerlinkissue38448 superseder
2019-10-24 09:18:32vstinnersetmessages: + msg355310
2019-10-21 22:33:42vstinnersetmessages: + msg355107
2019-10-21 15:47:12vstinnersetmessages: + msg355079
2019-10-21 11:20:37vstinnersetmessages: + msg355053
2019-10-21 11:20:00vstinnercreate