Php/docs/sem.configuration

From Get docs

Runtime Configuration

The behaviour of these functions is affected by settings in php.ini.

Semaphore Configuration Options
Name Default Changeable Changelog
sysvshm.init_mem 10000 PHP_INI_SYSTEM  

For further details and definitions of the PHP_INI_* modes, see the Where a configuration setting may be set. Here's a short explanation of the configuration directives.

sysvshm.init_mem int
A default size of the shared memory segment.