http://drupal.org/project/drupal_php_ext

Response time:		        0.15 secs
Transaction rate:	       33.01 trans/sec
A small gain of maybe just over 1%, but there is some margin-of-error wiggle-room here. Let's spend some quality time with kcachegrind to figure out why it we are not getting more out of this.


After enabling the extension:

So, it should be showing some performance improvements. However, looking at the code of the extension: 

PHP_RINIT_FUNCTION(drupal_extension)
{
        // Initialize arrays to hold static variables on a per page request basis.
        // Doing this in MINIT will make the same arrays persistent across multiple requests
        // which is probably not wanted.
        ZEND_INIT_MODULE_GLOBALS(drupal_extension, php_drupal_extension_init_globals, NULL)
        return SUCCESS;
}

PHP_RSHUTDOWN_FUNCTION(drupal_extension)
{
        // Apparently function_table is persistent across requests so we have to remove our
        // changes or else we'll bork subsequent requests.
        // TODO: Add a global flag to track whether these functions were ever overriden.
        zend_hash_del(EG(function_table), "check_plain", sizeof("check_plain"));
        zend_hash_del(EG(function_table), "drupal_static", sizeof("drupal_static"));

        zend_hash_destroy(DRUPAL_EXTENSION_G(drupal_static_ext_zdata));
        zend_hash_destroy(DRUPAL_EXTENSION_G(drupal_static_ext_zdefault));

        FREE_HASHTABLE(DRUPAL_EXTENSION_G(drupal_static_ext_zdata));
        FREE_HASHTABLE(DRUPAL_EXTENSION_G(drupal_static_ext_zdefault));

        return SUCCESS;
}