Does memory_get_peak_usage() returns memory of the whole php or just the current execution?

Let's say i call memory_get_peak_usage(true) and it returns 2.5MB.

• Does it means that the whole php开发者_运维技巧 (all clients) is causing that peak?

• Or does it means that if I have 100 clients acessing the same time, the peak could be 250MB?

It returns the peak usage for the current request only.

From the doc:

Returns the peak of memory, in bytes, that's been allocated to your PHP script.

To remove any ambiguities from the docs:

memory_get_peak_usage() calls the internal zend_memory_peak_usage() function, which returns AG(mm_heap)->peak.

AG(mm_heap)->peak is reset to 0 in zend_mm_shutdown(), which is called in php_request_shutdown() at the end of each request.

So it's the peak memory usage for the current request only.