Message148308
| Author |
neologix |
| Recipients |
dmalcolm, eli.bendersky, flox, kaifeng, neologix, pitrou, python-dev |
| Date |
2011年11月25日.08:17:06 |
| SpamBayes Score |
5.803979e-07 |
| Marked as misclassified |
No |
| Message-id |
<CAH_1eM2pTRsFd86bmf-ztdVhfUHA3Cx7EPT2mjq1pxxbvWB4pQ@mail.gmail.com> |
| In-reply-to |
<1322181000.89.0.989499659253.issue11849@psf.upfronthosting.co.za> |
| Content |
> For the record, this seems to make large allocations slower:
>
> -> with patch:
> $ ./python -m timeit "b'x'*200000"
> 10000 loops, best of 3: 27.2 usec per loop
>
> -> without patch:
> $ ./python -m timeit "b'x'*200000"
> 100000 loops, best of 3: 7.4 usec per loop
>
Yes, IIRC, I warned it could be a possible side effect: since we're
now using mmap() instead of brk() for large allocations (between 256B
and 32/64MB), it can be slower (that's the reason adaptive mmap
threadshold was introduced in the first place).
> More surprising is that, even ignoring the allocation cost, other operations on the memory area seem more expensive:
Hum, this it strange.
I see you're comparing 3.2 and default: could you run the same
benchmark on default with and without the patch ? |
|