[Yaml-core] Speed comparison between vanilla pyyaml and pyyaml+libyaml

[<jn...@gm...>]

I ran across the following posts a little while ago:

I'ma heavy yaml consumer, so I thought I'd experiment with vanilla YAML  
speed runs of the same benchmark, and then with pyyaml+libyaml, with cython  
installed. What bothers me is that there's a negligible difference in  
speed, even with libyaml installed, and pyyaml using the cyaml extension:

Here's the relevant numbers:

Vanilla PyYAML:

ser_yaml (6.320s) 623436 bytes
ser_yaml_compressed (6.410s) 291050 bytes
serde_yaml (18.550s)

PyYAML + libyaml:

ser_yaml (6.150s) 623488 bytes
ser_yaml_compressed (6.240s) 291175 bytes
serde_yaml (18.950s)

On the serde_yaml test, I've consistently gotten worse speeds than plain  
old pyyaml. I'm wondering if you guys have any thoughts/ideas on this. I've  
posted the modified benchmark code to:

http://jessenoller.com/code/test_yaml.py

FWIW, this is on a dual core OS/X box. In the morning, I'll try running it  
on an available Linux machine just for sanity's sake

jesse