On Fri, Oct 8, 2021 at 8:11 AM Guido van Rossum <guido@python.org> wrote:
To be clear, Sam’s basic approach is a bit slower for single-threaded code, and he admits that.

Is it also slower even when running with PYTHONGIL=1? If it could be made the same speed for single-threaded code when running in GIL-enabled mode, that might be an easier intermediate target while still adding value.

—Chris


But to sweeten the pot he has also applied a bunch of unrelated speedups that make it faster in general, so that overall it’s always a win. But presumably we could upstream the latter easily, separately from the GIL-freeing part.

On Fri, Oct 8, 2021 at 07:42 Łukasz Langa <lukasz@langa.pl> wrote:

> On 8 Oct 2021, at 10:13, Steven D'Aprano <steve@pearwood.info> wrote:
>
> Hi Sam,
>
> On Thu, Oct 07, 2021 at 03:52:56PM -0400, Sam Gross wrote:
>
>> I've been working on changes to CPython to allow it to run without the
>> global interpreter lock. I'd like to share a working proof-of-concept that
>> can run without the GIL.
>
> Getting Python to run without the GIL has never been a major problem for
> CPython (and of course some other Python interpreters don't have a GIL
> at all).

On the first page of Sam's design overview he references Gilectomy by name.

> Single threaded code is still, and always will be, an important part of
> Python's ecosystem. A lot of people would be annoyed if the cost of
> speeding up heavily threaded Python by a small percentage would be to
> slow down single-threaded Python by a large percentage.

Quoting that same design document, Sam writes: "The new interpreter
(together with the GIL changes) is about 10% faster than CPython 3.9
on the single-threaded pyperformance benchmarks."

- Ł
_______________________________________________
Python-Dev mailing list -- python-dev@python.org
To unsubscribe send an email to python-dev-leave@python.org
https://mail.python.org/mailman3/lists/python-dev.python.org/
Message archived at https://mail.python.org/archives/list/python-dev@python.org/message/JO7OQCHZKIFNKSXTTXT2JBCF5H47M7OO/
Code of Conduct: http://python.org/psf/codeofconduct/
--
--Guido (mobile)
_______________________________________________
Python-Dev mailing list -- python-dev@python.org
To unsubscribe send an email to python-dev-leave@python.org
https://mail.python.org/mailman3/lists/python-dev.python.org/
Message archived at https://mail.python.org/archives/list/python-dev@python.org/message/XQOOGKH5PIFBHJRK7W2LMX32DIGIH4KX/
Code of Conduct: http://python.org/psf/codeofconduct/