New submission from STINNER Victor <vstin...@python.org>:
Python leaks around 66 memory blocks at exit. Most of them are allocated by
_Py_Quicken() of Python/specialize.c.
int
_Py_Quicken(PyCodeObject *code) {
...
SpecializedCacheOrInstruction *quickened = allocate(entry_count,
instr_count);
...
code->co_quickened = quickened;
...
return 0;
}
The memory is stored in PyCodeObject.co_quickened member. This member *is*
cleared by the code object deallocator function, code_dealloc():
static void
code_dealloc(PyCodeObject *co)
{
...
if (co->co_quickened) {
PyMem_Free(co->co_quickened);
_Py_QuickenedCount--;
}
...
}
I read recently that deepfreeze creates "immortal" code objects (refcount of
999999999). I guess that it's related.
I used Valgrind to look for memory leaked by Python at exit:
$ PYTHONMALLOC=malloc valgrind --show-leak-kinds=all --leak-check=full
--log-file=valgrind.log --num-callers=50 ./python -c pass
Extract of valgrind.log:
==1266888== 5,528 bytes in 13 blocks are still reachable in loss record 33 of 33
==1266888== at 0x484186F: malloc (vg_replace_malloc.c:381)
==1266888== by 0x544DBC: _PyMem_RawMalloc (obmalloc.c:100)
==1266888== by 0x545B13: PyMem_Malloc (obmalloc.c:618)
==1266888== by 0x6AAE6F: allocate (specialize.c:231)
==1266888== by 0x6AB3F0: _Py_Quicken (specialize.c:420)
==1266888== by 0x622CE7: _Py_IncrementCountAndMaybeQuicken
(pycore_code.h:152)
==1266888== by 0x626315: _PyEval_EvalFrameDefault (ceval.c:1792)
==1266888== by 0x622B13: _PyEval_EvalFrame (pycore_ceval.h:53)
==1266888== ...
==1266888==
==1266888== LEAK SUMMARY:
==1266888== definitely lost: 0 bytes in 0 blocks
==1266888== indirectly lost: 0 bytes in 0 blocks
==1266888== possibly lost: 0 bytes in 0 blocks
==1266888== still reachable: 24,240 bytes in 66 blocks
==1266888== suppressed: 0 bytes in 0 blocks
See also bpo-46449: "Deep-freezed modules create inconsistency in
sys.gettotalrefcount() (_Py_Reftotal)".
----------
components: Interpreter Core
messages: 411315
nosy: vstinner
priority: normal
severity: normal
status: open
title: Not all memory allocated by _Py_Quicken() is not released at Python exit
versions: Python 3.11
_______________________________________
Python tracker <rep...@bugs.python.org>
<https://bugs.python.org/issue46476>
_______________________________________
_______________________________________________
Python-bugs-list mailing list
Unsubscribe:
https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
