#48046 [Com]: memory does not free with unset?

ID: 48046 Comment by: boettcher at freshframes dot com Reported By: nikitin at freshframes dot com Status: Feedback Bug Type: Performance problem Operating System: linux suse 10.3 PHP Version: 5.2.9 New Comment: You need 250MB memory_limit to execute. ----- This script uses ~200MB at the end of script and got a peak of ~200MB. If you uncomment the unsets you'll have less memory (current) usage and a slight less memory peak ----- <?php ini_set( 'memory_limit', '1000M' ); $data = $array_1 = $array_2 = $array_3 = array(); for( $i = 0; $i < 10000; $i++ ) $array_1[] = rand( 3456, 987641234 ) . str_repeat( implode( '', range( 'a', 'z' ) ), rand( 70, 200 )); $data = array_merge( $data, $array_1 ); #unset( $array_1 ); for( $i = 0; $i < 20000; $i++ ) $array_2[] = rand( 1232, 987641234 ) . str_repeat( implode( '', range( 'a', 'z' ) ), rand( 160, 250 )); $data = array_merge( $data, $array_2 ); #unset( $array_2 ); for( $i = 0; $i < 30000; $i++ ) $array_3[] = rand( 1239, 987641234 ) . str_repeat( implode( '', range( 'a', 'z' ) ), rand( 40, 100 )); $data = array_merge( $data, $array_3 ); #unset( $array_3 ); #unset( $data ); $memory_peak = round( memory_get_peak_usage( true ) / pow(1024, 2), 2 ); $memory = round( memory_get_usage( true ) / pow(1024, 2), 2 ); echo "\nW/O Unset\nCurrent REAL Usage: " . $memory . 'MB -- Peak: ' . $memory_peak . "MB\n\n"; ?> --- statistics of my server (debian 4.0) [4 tests] -- W/O Unset Current REAL Usage: 207.75MB -- Peak: 212.75MB - W/O Unset Current REAL Usage: 208.25MB -- Peak: 213MB - W/O Unset Current REAL Usage: 208MB -- Peak: 212.75MB - W/O Unset Current REAL Usage: 208MB -- Peak: 212.75MB -- and now with unset uncommented [4 tests] -- With Unset Current REAL Usage: 40.25MB -- Peak: 209.75MB - With Unset Current REAL Usage: 40MB -- Peak: 209.75MB - With Unset Current REAL Usage: 38.75MB -- Peak: 209.75MB - With Unset Current REAL Usage: 37.75MB -- Peak: 209.75MB Previous Comments: ------------------------------------------------------------------------ [2009-04-22 13:54:28] scottmac@php.net Thank you for this bug report. To properly diagnose the problem, we need a short but complete example script to be able to reproduce this bug ourselves. A proper reproducing script starts with <?php and ends with ?>, is max. 10-20 lines long and does not require any external resources such as databases, etc. If the script requires a database to demonstrate the issue, please make sure it creates all necessary tables, stored procedures etc. Please avoid embedding huge scripts into the report. Memory is never freed back to the system until the request ends, PHP will however re-use the memory assuming that a block the right size can be found. ------------------------------------------------------------------------ [2009-04-22 13:51:07] crrodriguez at opensuse dot org unset has never freed memory, memory is freed at script shutdown. ------------------------------------------------------------------------ [2009-04-22 13:11:25] nikitin at freshframes dot com Description: ------------ I have a script running on two servers working on exactly the same data. First server is a debian system with php 5.2.8, where no problems with memory occur. Second server is a suse 10.3 with php 5.2.9, where i get: PHP Fatal error: Allowed memory size of 2097152000 bytes exhausted (tried to allocate 82 bytes) in ... Reproduce code: --------------- The output of the memory usage compared for each server: Here the 5.2.8 debian: 19 - simple (5) : AR1312-16 (16.23/16.49) <br /> 20 - configurable (5) : AR1312 <br /> 20 - simple (0) : AR1331-04 (16.33/16.58) <br /> 21 - simple (0) : AR1331-07 (16.36/16.62) <br /> 22 - simple (0) : AR1331-09 (16.40/16.65) <br /> Here the 5.2.9 suse server: 20 - configurable (5) : AR1312 <br /> 20 - simple (0) : AR1331-04 (91.98/92.06) <br /> 21 - simple (0) : AR1331-07 (94.03/94.32) <br /> 22 - simple (0) : AR1331-09 (96.08/96.37) <br /> 23 - configurable (0) : AR1331 <br /> 23 - simple (7) : AR1338-16 (99.20/99.28) <br /> -> memory in brackets (actual/peak) -> seems that php 5.2.9 has bad memory management? ------------------------------------------------------------------------ -- Edit this bug report at http://bugs.php.net/?id=48046&edit=1