few questions about op_array

Hey Lin:

Hi Dmitry,

I changed and tested it, and it looks like it gains some improvements. how
do you compare the benchmark result? is there a tool doing it?

I currently do:

./sapi/cli/php Zend/bench.php

The result:

https://gist.github.com/4bbc33b7b5dcedc6bd66

Acutally, simply bench.php testing is very un-stable. in generally, we
prefer using real-life app to test, like wordpress.

Basically, we use callgrind to collect the IRs , like valgrind
--tool=callgrind --instr-atstart=yes php-cgi -T 100 wordpress/index.php ( I
may type args wrong).

But in this case(cache friendly), you may try to use perf to collect cache
miss changing.

thanks

Hi all,

I am looking into zend op_array structure, and few questions raised in
my mind:

1. Why op_array->refcount uses *uint32 instead of uint32, is there a
   reason? if we can replace it with uint32, then we might save one emalloc
   call for memory allocation for every op_array allocation?

We may have few different op_array structures with the same opcodes but
with different names for example. So just uint32won't work.

2. There are also a lot of information saved in the op_array structure,
   if we can move line_start, line_end, doc_comments...etc into an external
   structure, then we might be able to reduce the op_array size and decrease
   the cache miss? is it doable?

I'm not sure if patritioning data of op_array, into frequntly and rarely
used, may make any significant difference. Because we usually work only
with a single instance of op_array in each moment. Fields reordering alrecy
helped to reduce cache-misses. But I may be wrog :)

Thanks. Dmitry.

Cheers,
Yo-An Lin
https://github.com/c9s

--
Best Regards,

Yo-An Lin

--
Xinchen Hui
@Laruence
http://www.laruence.com/