Section A.9. memory_limit

A.9. memory_limit

To prevent poorly written scripts from consuming all of the available memory, the memory_limit directive can be used to indicate a maximum amount of memory (indicated in bytes or shorthand notation such as 8M).

Although the best value is very application specific, I recommend using the default value of 8M in most cases.

The memory_limit directive is available only when PHP is compiled with enable-memory-limit.