On Wed, 11 Apr 2012 15:31:09 +0200 Stefan Behnel <stefan...@behnel.de> wrote: > > Ok. I guess once the code is there, the hardware will eventually catch up. > > However, I'm not sure what you consider "large". A lot of manipulation > operations for the builtin types are not all that involved, at least in the > "normal" cases (read: fast paths) that involve no memory reallocation etc., > and anything that can be called by and doesn't call into the interpreter > would be a complete and independent transaction all by itself, as the GIL > is allowed to be released between any two ticks.
I think Armin's plan is not to work at the bytecode level, but make transactions explicit (at least in framework code - e.g. Twisted or Stackless -, perhaps not in user code). Perhaps he can elaborate on that. > Do you know if hybrid TM is possible at this level? I.e. short transactions > run in hardware, long ones in software? (Assuming we know what's "long" and > "short", I guess...) There are other issues than the size of transactions. For example, one issue is that not all operations may be allowed in a transaction: “In addition, there are a number of instructions that may cause an abort on specific implementations. These instructions include x87 and MMX, mixed access to XMM and YMM registers, updates to non-status parts of EFLAGs, updating segment, debug or control registers, ring transitions, cache and TLB control instructions, any non-writeback memory type accesses, processor state save, interrupts, I/O, virtualization (VMX), trusted execution (SMX) and several miscellaneous types.” http://realworldtech.com/page.cfm?ArticleID=RWT021512050738 So, realistically, a (S)TM implementation in CPython (and probably also in PyPy) would have to stand on its own merits, rather than betting on pie-in-the-sky improvements of HTM implementations. Regards Antoine. _______________________________________________ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
