The default installation of php 8.0 I mentioned in the previous post has JIT built-it. But, here is a big BUT, JIT is not enabled.
I run this php scrip, or bubble.php, at the default settings of PHP 8.0.1. About 10 runs, I got the average time is 0.095 seconds.
Then I try to config the php-fpm to make JIT work.
opcache.enable =1 opcache.jit_buffer_siez = 100M opcache.jit = 1235
Restart the php8.0-fpm service.
Later I re-run the bubble.php script 10 times. The average time is 0.053 seconds.
As a comparison, php 8.0 JIT vs no-JIT is about 45% faster.
I tested the bubble.php on PHP 7.4.14, as well.
The average time is 0.121 seconds.
It worths upgrading the php-fpm service from 7.4 to 8.0 now if I can solve all the compatible issues. And I will enable JIT, because JIT brings the most improvement of performance.