From: joe at estara dot com
Operating system: Linux
PHP version: 5.1.4
PHP Bug Type: Apache2 related
Bug description: Use 'unserialize', then a large amount of memory is not
returned to the OS
Description:
------------
If you use unserialize on a large multidimensional array, each apache
process it runs in ends up taking up over 68m of ram (the actual size
depends on your array that you're unserializing) This is actual ram
(Resident minus shared ram), and doesn't return it to the operating system
after the script exits. Since you have say MaxClients in apache2 of 150,
150 times 68m of ram means swapping to death. This is using prefork.
Reproduce code:
---------------
<?php
ini_set("memory_limit", "64M");
# ziplatlong is an array, with zip code as a key and a 2 element lat long
array as the value
$s = file_get_contents("ziplatlong");
$zip = unserialize($s);
preg_match("/foo/", $zip["00601"][0]);
Expected result:
----------------
I'd expect most of the ram returned to the operating system. When I do
something similar, use the same levels of ram, apache only takes up ~10M
of ram, even though it uses ~64M while processing.
<?php
ini_set("memory_limit", "64M");
for($i=0;$i<50; $i++)
$s[$i] = file_get_contents("ziplatlong");
preg_match("/foo/", $s[38]);
Actual result:
--------------
Machine swaps to death.
--
Edit bug report at http://bugs.php.net/?id=37929&edit=1
--
Try a CVS snapshot (PHP 4.4):
http://bugs.php.net/fix.php?id=37929&r=trysnapshot44
Try a CVS snapshot (PHP 5.2):
http://bugs.php.net/fix.php?id=37929&r=trysnapshot52
Try a CVS snapshot (PHP 6.0):
http://bugs.php.net/fix.php?id=37929&r=trysnapshot60
Fixed in CVS: http://bugs.php.net/fix.php?id=37929&r=fixedcvs
Fixed in release:
http://bugs.php.net/fix.php?id=37929&r=alreadyfixed
Need backtrace: http://bugs.php.net/fix.php?id=37929&r=needtrace
Need Reproduce Script: http://bugs.php.net/fix.php?id=37929&r=needscript
Try newer version: http://bugs.php.net/fix.php?id=37929&r=oldversion
Not developer issue: http://bugs.php.net/fix.php?id=37929&r=support
Expected behavior: http://bugs.php.net/fix.php?id=37929&r=notwrong
Not enough info:
http://bugs.php.net/fix.php?id=37929&r=notenoughinfo
Submitted twice:
http://bugs.php.net/fix.php?id=37929&r=submittedtwice
register_globals: http://bugs.php.net/fix.php?id=37929&r=globals
PHP 3 support discontinued: http://bugs.php.net/fix.php?id=37929&r=php3
Daylight Savings: http://bugs.php.net/fix.php?id=37929&r=dst
IIS Stability: http://bugs.php.net/fix.php?id=37929&r=isapi
Install GNU Sed: http://bugs.php.net/fix.php?id=37929&r=gnused
Floating point limitations: http://bugs.php.net/fix.php?id=37929&r=float
No Zend Extensions: http://bugs.php.net/fix.php?id=37929&r=nozend
MySQL Configuration Error: http://bugs.php.net/fix.php?id=37929&r=mysqlcfg
