STINNER Victor <victor.stin...@gmail.com> added the comment: Nathaniel Smith: "Given the complexities here, and that the Track/Untrack functions are public now, I do wonder if the actual aligned allocation routines should just be an internal API (i.e., not exposed in Python.h)."
I don't see why we would hide PyMem_AlignedAlloc() but requires to implement aligned_alloc in PyMem_SetAllocators(). The plan is also to slowly use PyMem_AlignedAlloc() internally for performance. Can you elaborate the "complexities"? Do you mean that the proposed PyMem_AlignedAlloc() API is more complex than calling directly posix_memalign()? PyMem_AlignedAlloc() is designed for performance. For best performances, CPUs require memory to be aligned on convenient values like powers of 2 ;-) I also understand that alignment must be a multiple of sizeof(void*) because CPU work on "CPU words". On a 64-bit CPU, a word is 8 bytes. If the memory is aligned on 4 bytes, it may have to fetch two words, you loose the advantage of memory alignment. I understand that PyMem_AlignedAlloc() requirements come from the CPU arhcitecture, it's not an arbitrary limitation just for the fun ;-) ---------- _______________________________________ Python tracker <rep...@bugs.python.org> <https://bugs.python.org/issue18835> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
