[PATCH] suppressing realpath() with APC + tiny patches

I'm glad somebody is working on a patch for this performance problem.

I will test it !

Thanks.

Jean-François Bustarret
eTF1 - Architect

-----Message d'origine-----
De : Masaki Fujimoto [mailto:fujimoto@php.net]
Envoyé : jeudi 6 mai 2004 15:36
À : internals@lists.php.net
Objet : [PHP-DEV] [PATCH] suppressing realpath() with APC +

tiny patches

Hello,

These days I've been working on some tasks to reduce I/O system calls

(lstat64, stat64, open and so on) of PHP for some reasons and

as the result of it, I noticed that with the APC + very small two

pathes we can suppress most of realpath() calls (although currently

I'm not sure this is the correct method or not...):

http://eth.jp/php-cvs-20040506-delayed-fopen.patch.txt
(patch against current 4.3 tree, because APC is not yet fully

compatible with PHP 5)
http://eth.jp/apc-2.0.3-delayed-fopen.patch.txt
(patch against APC-2.0.3, current CVS-HEAD is somehow unstable...)

So please try and review if you're curious about suppressing

realpath() calls:)

Usage:

1. apply patches to current 4.3 tree, and APC-2.0.3
2. buidconf and configure PHP as always with --enable-delayed-fopen

option

3. build and install PHP and APC as always
4. add "delayed_fopen=1" entry to your php.ini

And details are as follows:

As the recent thread and some other threads show (which

listed below),

PHP requires quite a few I/O system calls especially when

large number

of scripts are include_once()ed. And these are not ignorable

for the websites with more than 1 million hits per hour although it

has nothing to do with small sites.

[Performance Consideration of 1 class per file]
http://marc.theaimsgroup.com/?l=php-dev&m=108279256414391&w=2

[Performance degradation]
http://www.phpbuilder.com/lists/php-developer-list/2003022/0226.php

The main concern here is the lstat64() by realpath(), and open() by

searching for include_paths (when many include_paths are set).

I think suppressing open() (which will result in ENOENT) is not so

easy (because we need some other new caching system for

include_paths), but perhaps we can easily reduce realpath() for

included scritpts with APC, because APC does not use an opned file

handle when cache hits.

So, my patch skips zend_open() until open_file_scanning() is called

inside zend_compile_file() when include_once() or require_once() is

called, so that zend_open() is not called when the target script is

cached in APC. As a result of this, we can reduce most of realpath()

calls by include_once() and required_once().

These patches are not yet verified well so comments are welcome!

Best regards,
Masaki Fujimoto
fujimoto@php.net

---

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