[xdebug-general] Xdebug slowdown since PHP 5.4.14

Hi all,

At work I'm stuck on Windows XP so I use PHP 5.4.x for dev work.

I recently upgraded to the latest version in 5.4. branch and noticed a
considerable slowdown when XDebug is enabled. I created a super-simple
test script which demonstrates this:
https://gist.github.com/ihabunek/7233111

Here's the result of running it (in CLI) on different versions of PHP
with and without xdebug (latest version - 2.2.3). Results are in
seconds.

Running tests without xdebug
PHP 5.4.0: 0.082
PHP 5.4.1: 0.081
PHP 5.4.2: 0.08
PHP 5.4.3: 0.083
PHP 5.4.4: 0.081
PHP 5.4.5: 0.079
PHP 5.4.6: 0.081
PHP 5.4.7: 0.082
PHP 5.4.8: 0.091
PHP 5.4.9: 0.087
PHP 5.4.10: 0.097
PHP 5.4.11: 0.089
PHP 5.4.12: 0.085
PHP 5.4.13: 0.091
PHP 5.4.14: 0.094
PHP 5.4.15: 0.094
PHP 5.4.16: 0.094
PHP 5.4.17: 0.094
PHP 5.4.18: 0.094
PHP 5.4.19: 0.078
PHP 5.4.20: 0.094
PHP 5.4.21: 0.094
.
Running tests with xdebug
PHP 5.4.0: 0.264
PHP 5.4.1: 0.267
PHP 5.4.2: 0.273
PHP 5.4.3: 0.277
PHP 5.4.4: 0.268
PHP 5.4.5: 0.272
PHP 5.4.6: 0.267
PHP 5.4.7: 0.272
PHP 5.4.8: 0.287
PHP 5.4.9: 0.275
PHP 5.4.10: 0.277
PHP 5.4.11: 0.277
PHP 5.4.12: 0.264
PHP 5.4.13: 0.278
PHP 5.4.14: 0.922
PHP 5.4.15: 0.969
PHP 5.4.16: 0.938
PHP 5.4.17: 0.984
PHP 5.4.18: 0.953
PHP 5.4.19: 0.969
PHP 5.4.20: 0.922
PHP 5.4.21: 0.906

Notice the drastic change for the worse starting from 5.4.14. I know
XDebug causes a performance hit, but this pretty much makes it
unusable for me. Any ideas why this is happening?

BTW, when running without xdebug i use the -n flag to skip loading of
php.ini. When running with xdebug, i use a php.ini with a single line:
zend_extension=/path/to/php_xdebug-2.2.3-5.4-vc9.dll

Regards,
Ivan
Received on Wed Oct 30 2013 - 14:17:20 GMT