Bug #74174 [Asn->Fbk]: Memory allocation problem

Edit report at https://bugs.php.net/bug.php?id=74174&edit=1 ID: 74174 Updated by: dmitry@php.net Reported by: enleury at gmail dot com Summary: Memory allocation problem -Status: Assigned +Status: Feedback Type: Bug Package: Performance problem Operating System: Ubuntu PHP Version: 7.1.2 Assigned To: dmitry Block user comment: N Private report: N New Comment: This is not a bug. If you compare peak memory usage, PHP-7 wins. PHP-7 just manages memory differently. It allocates system memory by bigger chunks (2MB) and doesn't return free chunks back to system immediately, assuming that script may request the same amount again. Previous Comments: ------------------------------------------------------------------------ [2017-02-27 12:31:29] enleury at gmail dot com Description: ------------ Memory is not freed after return from the method. Looks like a heap defragmentation issue (https://bugs.php.net/bug.php?id=53669), but it works fine on 5.x branches. Online test script for 5.x and 7.x branches: https://3v4l.org/2OVeU#output Test script: --------------- <?php function create_docs($amount) { $documents = []; for ($i = 0; $i < $amount; $i++) { $documents[] = ['a' => $i]; } } echo memory_get_usage(true), PHP_EOL; create_docs(5000); echo memory_get_usage(true), PHP_EOL; create_docs(50000); echo memory_get_usage(true), PHP_EOL; create_docs(5000); echo memory_get_usage(true), PHP_EOL; Expected result: ---------------- 262144 524288 524288 524288 Actual result: -------------- 2097152 4194304 20971520 20971520 ------------------------------------------------------------------------ -- Edit this bug report at https://bugs.php.net/bug.php?id=74174&edit=1