ID: 50351 Updated by: j...@php.net Reported By: rlillack at yasni dot de Status: Verified Bug Type: Scripting Engine problem Operating System: 64/32bit linux PHP Version: 5.3.1 New Comment:
See also bug #48781 (propably related as well) Previous Comments: ------------------------------------------------------------------------ [2009-12-01 13:48:23] rlillack at yasni dot de This seems to be related to the new cyclic garbage collector trying to free memory after each allocation?! A rather simple workaround is to insert gc_disable() before and gc_enable() after entering the loop. ------------------------------------------------------------------------ [2009-12-01 13:38:56] j...@php.net My results were done with i686.. ------------------------------------------------------------------------ [2009-12-01 13:37:27] j...@php.net [j...@localhost ~]$ src/build/php_5_2/sapi/cli/php -n -d memory_limit=2G t.php time: 4.10 secs, memory usage 371.39 MiB. [j...@localhost ~]$ src/build/php_5_3/sapi/cli/php -n -d memory_limit=2G t.php time: 25.97 secs, memory usage 383.46 MiB. ------------------------------------------------------------------------ [2009-12-01 12:53:42] rlillack at yasni dot de Description: ------------ PHP 5.3 did indeed introduce many performance improvements, but we spotted a rather hard regression with handling a large amount of objects that are allocated at the same time. Running the following test case on one of our web servers yield this result with a vanilla build of 5.2.11: time: 1.28 secs, memory usage 376.48 MiB. and this with 5.3.1: time: 13.44 secs, memory usage 400.62 MiB. (command line in both cases: PREFIX/bin/php -d memory_limit=2G testcase.php) The regression at least since the PHP 5.3 release candidates. Both were fresh build straight from the tarball, No extensions, etc. Opcode caches do not help. --with-zend-vm does not help. Reproduce code: --------------- <?php $start = microtime(TRUE); $a = array(); foreach (range(1, 1000000) as $i) { $a []= new StdClass; } printf("time: %s secs, memory usage %s MiB.\n", number_format(microtime(TRUE) - $start, 2), number_format(memory_get_usage() / 1024 / 1024, 2)); Expected result: ---------------- PHP 5.3.1 should not be any slower than 5.2.11 is. :) Actual result: -------------- PHP 5.3.1 is ten times slower in this test case. One of our apps does only handle 1/4th queries/s with 5.3 on a production server. ------------------------------------------------------------------------ -- Edit this bug report at http://bugs.php.net/?id=50351&edit=1