I received this message during an iTop installation. If you google this, it appears on commercial websites above their content.
Warning: filter_var(): Allocation of JIT memory failed, PCRE JIT will be disabled. This is likely because of security restrictions. Either grant PHP permission to execute memory, or set pcre.jit=0 in /var/www/html/itop/web/application/utils.php on line 338.
The "fix" is included in the warning message, but I would like to know more about what's going on. Maybe I want PHP to allocate executable memory. Any insight would be appreciated.