I use child\_process to excute yslow.js by phantomjs. 
Example(CLI): 

```
 phantomjs yslow.js --info all --format json url

```

We can get the analytic data that yslow.js return to me after analyzing.

But sometimes the data yslow.js return to me can not be a complete json file. Is seem the callback params "stdout" can not be too a large length data. I guess If the data is too large can infect the params stdout...

Has anyone ever encountered such a problem ?