MAX_CHILDREN=$(((TOTAL_MEM - 512) / PROC_MEM))
If the MAX_CHILDREN variable becomes negative, funny things happen, i.e. php-fpm does not want to start.
```
MAX_CHILDREN=$(((TOTAL_MEM - 512) / PROC_MEM))
```
If the `MAX_CHILDREN` variable becomes negative, funny things happen, i.e. `php-fpm` does not want to start.