如何找到使用最多CPU的PHP代码行

Question

I am currently using EC2, and when testing (with locust.io) 100 concurrent users, I am achieving a RPS of 15. However, my CPU usage is nearly 100%.

Would anyone know how to track down the line/lines of PHP 7 code that are using most CPU, so I can optimize them?

Answer 1

I'd suggest xdebug and kcachegrind to profile and analyse the behaviour of your code.

Configure xdebug like this to enable profiling:

xdebug.profiler_enable = 1
xdebug.profiler_output_name = xdebug.out.%t
xdebug.profiler_output_dir = /tmp
xdebug.profiler_enable_trigger = 1

If you pass XDEBUG_PROFILE as POST or GET paramteter, xdebug will produce profiling data in the configured location.

Open these files with kcachegrind to drill into it.

Beware: Execution while profiling will take its time, and the files produced can get pretty big -- have an eye on diskusage.