STINNER Victor <vstin...@redhat.com> added the comment:
The x86-64 ABI requires that memory allocated on the heap is aligned to 16 bytes. On x86-64, glibc malloc(size) aligns on 16 bytes for size >= 16, otherwise align to 8 bytes. So the glibc doesn't respect exactly the ABI. I understand that a compiler will not use instructions which require 16B align on a memory block smaller than 16B, so align to 8B for size < 16B should be fine *in practice*. Python objects are at least 16B because of PyObject header. Moreover, objects tracked by the GC gets additional 16B header from PyGC_Head. But pymalloc is also used for PyMem_Malloc() since Python 3.6, and PyMem_Malloc() is used to allocate things which are not PyObject. ---------- _______________________________________ Python tracker <rep...@bugs.python.org> <https://bugs.python.org/issue27987> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
