Description

vstinner

opened on Jul 6, 2017

Issue body actions

BPO	30866
Nosy	@vstinner, @serhiy-storchaka
PRs	[2.7] bpo-30866: Add _testcapi.stack_pointer() #2600 bpo-30866: Add _testcapi.stack_pointer() #2601 [3.6] bpo-30866: Add _testcapi.stack_pointer() #2602 [3.5] bpo-30866: Add _testcapi.stack_pointer() #2603
Files	stack_overflow-3.py

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

Show more details

GitHub fields:

assignee = None
closed_at = <Date 2017-09-15.16:38:44.368>
created_at = <Date 2017-07-06.10:51:19.887>
labels = ['3.7']
title = 'Add _testcapi.stack_pointer() to measure the C stack consumption'
updated_at = <Date 2017-09-15.16:38:44.367>
user = 'https://github.com/vstinner'

bugs.python.org fields:

activity = <Date 2017-09-15.16:38:44.367>
actor = 'vstinner'
assignee = 'none'
closed = True
closed_date = <Date 2017-09-15.16:38:44.368>
closer = 'vstinner'
components = []
creation = <Date 2017-07-06.10:51:19.887>
creator = 'vstinner'
dependencies = []
files = ['46992']
hgrepos = []
issue_num = 30866
keywords = []
message_count = 6.0
messages = ['297822', '297824', '297826', '297829', '298060', '302271']
nosy_count = 2.0
nosy_names = ['vstinner', 'serhiy.storchaka']
pr_nums = ['2600', '2601', '2602', '2603']
priority = 'normal'
resolution = 'fixed'
stage = 'resolved'
status = 'closed'
superseder = None
type = None
url = 'https://bugs.python.org/issue30866'
versions = ['Python 3.7']

Activity

1. vstinner commented on Jul 6, 2017

   

   vstinner

   on Jul 6, 2017

   MemberAuthor

   More actions

   In issues bpo-28870, bpo-29227, bpo-29233 and bpo-29234, I worked on reducing the C stack consumption. I now would to add the _testcapi.stack_pointer() that I used to be able to easily measure the stack consumption.

   Try for example attached stack_overflow-3.py to measure the maximum number of C calls before a C stack overflow. The script also computes the average stack usage per C call for a specific kind of C call.
2. vstinner

   added

   3.7 (EOL)end of lifeend of life

   on Jul 6, 2017
3. serhiy-storchaka commented on Jul 6, 2017

   

   serhiy-storchaka

   on Jul 6, 2017

   Member

   More actions

   Usually we first merge a patch in master and after that cherry-pick it to other branches.
4. vstinner commented on Jul 6, 2017

   

   vstinner

   on Jul 6, 2017

   MemberAuthor

   More actions

   Usually we first merge a patch in master and after that cherry-pick it to other branches.

   Right. But in this case, I needed the patch for each branch, to run the test on all branches to write a blog post :-) Here are results (blog post spoiler!):

   Table showing the C stack consumption in bytes, and the difference compared to
   Python 3.5 (last release before I started working on FASTCALL):

   ==================== ================ ===== ================ ================
   Function 2.7 3.5 3.6 3.7
   ==================== ================ ===== ================ ================
   test_python_call 1,360 (+352) 1,008 1,120 (+112) 960 (-48)
   test_python_getitem 1,408 (+288) 1,120 1,168 (+48) 880 (-240)
   test_python_iterator 1,424 (+192) 1,232 1,200 (-32) 1,024 (-208)
   Total 4,192 (+832) 3,360 3,488 (+128) 2,864 (-496)
   ==================== ================ ===== ================ ================

   Table showing the number of function calls before a stack overflow,
   and the difference compared to Python 3.5:

   ==================== =================== ====== =================== ===================
   Function 2.7 3.5 3.6 3.7
   ==================== =================== ====== =================== ===================
   test_python_call 6,161 (-2,153) 8,314 7,482 (-832) 8,729 (+415)
   test_python_getitem 5,951 (-1,531) 7,482 7,174 (-308) 9,522 (+2,040)
   test_python_iterator 5,885 (-916) 6,801 6,983 (+182) 8,184 (+1,383)
   Total 17,997 (-4600) 22,597 21,639 (-958) 26,435 (+3,838)
   ==================== =================== ====== =================== ===================
5. vstinner commented on Jul 6, 2017

   

   vstinner

   on Jul 6, 2017

   MemberAuthor

   More actions

   I just published my blog post: "My contributions to CPython during 2017 Q1"
   https://haypo.github.io/contrib-cpython-2017q1.html

   See the "Stack consumption" section.
6. vstinner commented on Jul 10, 2017

   

   vstinner

   on Jul 10, 2017

   MemberAuthor

   More actions

   New changeset 64fa449 by Victor Stinner in branch 'master':
   bpo-30866: Add _testcapi.stack_pointer() (bpo-2601)
   64fa449
7. vstinner commented on Sep 15, 2017

   

   vstinner

   on Sep 15, 2017

   MemberAuthor

   More actions

   I added the function to the master branch.

   I changed my mind. I now consider that the function is no needed in other branches. It can be added manually if someone needs it.
8. vstinner

   closed this as completedon Sep 15, 2017
9. ezio-melotti

   transferred this issue fromon Apr 10, 2022

Issue actions