Bug #80135 [Opn->Dup]: Memory leak - some data structure is not shrunk

Edit report at https://bugs.php.net/bug.php?id=80135&edit=1 ID: 80135 Updated by: nikic@php.net Reported by: mvorisek at mvorisek dot cz Summary: Memory leak - some data structure is not shrunk -Status: Open +Status: Duplicate Type: Bug Package: Scripting Engine problem Operating System: any PHP Version: 7.4.10 Block user comment: N Private report: N New Comment: Duplicate of bug #33487. Previous Comments: ------------------------------------------------------------------------ [2020-09-22 17:28:10] mvorisek at mvorisek dot cz Description: ------------ see test script, there is some zval/GC data structure, that is currently not shrunk this is an issue for workers that normally process small and large requests occasionally, as once the data structure inside php engine is enlarged, it never goes back and memory per worker/process stays allocated Test script: --------------- function createGraph($c) { $objs = []; for ($i = 0; $i < $c; $i++) { $obj = new \stdClass(); $objs[] = $obj; $obj->x = $objs[mt_rand(0, count($objs) - 1)]; } } for ($i = 0; $i < 5; $i++) { createGraph(2 * 1000 * 1000); gc_collect_cycles(); echo round(memory_get_usage() / (1024 * 1024), 3) . " MiB\n"; } Expected result: ---------------- memory usage stays below 1 MiB Actual result: -------------- 16.361 MiB 16.361 MiB 16.361 MiB 16.361 MiB 16.361 MiB ------------------------------------------------------------------------ -- Edit this bug report at https://bugs.php.net/bug.php?id=80135&edit=1