I've just checked into APC CVS preliminary support for Lazy Loading classes and functions. This means that rather than copying function entries into EG(function_table) and EG(class_table) when an include happen it will mark the functions/classes as available and only actually insert them into the tables when they are called. This is done via hooks added into the various hash table lookups in PHP. I've placed a patch for PHP_5_3 at:
http://tekrat.com/downloads/bits/apc_lazy_php53.patch You should be able to apply the above patch to the latest PHP_5_3 branch, and recompile the latest APC CVS against it. Two ini settings enable/display lazy loading: apc.lazy_functions=On/Off apc.lazy_classes=On/OFf There's still some enhancements that I need to make in both PHP and APC for cleaner code and optimizations, but I wanted to get some early feedback to track down issues. In a final version I'd prefer the above patch to abstract all function lookups into a common function. I would love to hear about success/problems with this, as well as performance results or other suggestions. This was initially implement for Facebook's codebase, and dropped CPU usage by about 30%, today it's required for the site to operate normally. Although I expect smaller gains than this in other codebases (wordpress looks to be about 3%, Joomla and Zend Framework use autoloading and appear to get no visible gains). Alternative implementations would include replacing the function entries with an internal function that would load the opcodes when called, however I found this implementation to be problematic, still requires changes to PHP, and would also require inserting entries into the function/class tables which itself ends up being an expensive task for extremely large codebases. I look forward to hearing your feedback, -shire -- PHP Internals - PHP Runtime Development Mailing List To unsubscribe, visit: http://www.php.net/unsub.php
