From: sq6elt at wp dot pl
Operating system: Linux
PHP version: 5.2.5
PHP Bug Type: Performance problem
Bug description: unnecessary lstat64
Description:
------------
With a lot of includes, located deep in file system,
there may be a performance impact, because of a lot of
unnecessary lstats.
Why, when there is exactly specified path, any lstats are made.
Simple access is sufficient, or I missed something?
If some of these are required, then do it only once.
I have checked php4, it behaves in the same way.
There is no difference, when i use include, include_once, require,
require_once.
Reproduce code:
---------------
Create a directory tree:
mkdir -p /tmp/a/b/c/d/e/f/g/h/i/j
Two empty php scripts:
echo '<? ?>' > /tmp/a/b/c/d/e/f/g/h/i/j/a.php
echo '<? ?>' > /tmp/a/b/c/d/e/f/g/h/i/j/b.php
and a main script /tmp/t.php
<?
include "/tmp/a/b/c/d/e/f/g/h/i/j/a.php";
include "/tmp/a/b/c/d/e/f/g/h/i/j/b.php";
?>
Actual result:
--------------
Do a strace on t,php
strace /usr/bin/php5 t.php 2>&1 | grep lstat64
And guess what:
lstat64("/usr", {st_mode=S_IFDIR|0755, st_size=4096, ...}) = 0
lstat64("/usr/bin", {st_mode=S_IFDIR|0755, st_size=49152, ...}) = 0
lstat64("/usr/bin/php5", {st_mode=S_IFREG|0755, st_size=5510176, ...}) =
0
lstat64("/etc", {st_mode=S_IFDIR|0755, st_size=8192, ...}) = 0
lstat64("/etc/php5", {st_mode=S_IFDIR|0755, st_size=4096, ...}) = 0
lstat64("/etc/php5/cli", {st_mode=S_IFDIR|0755, st_size=4096, ...}) = 0
lstat64("/etc/php5/cli/php.ini", {st_mode=S_IFREG|0644, st_size=44278,
...}) = 0
lstat64("/tmp", {st_mode=S_IFDIR|S_ISVTX|0777, st_size=8192, ...}) = 0
lstat64("/tmp/t.php", {st_mode=S_IFREG|0644, st_size=94, ...}) = 0
lstat64("/tmp", {st_mode=S_IFDIR|S_ISVTX|0777, st_size=8192, ...}) = 0
lstat64("/tmp/a", {st_mode=S_IFDIR|0755, st_size=4096, ...}) = 0
lstat64("/tmp/a/b", {st_mode=S_IFDIR|0755, st_size=4096, ...}) = 0
lstat64("/tmp/a/b/c", {st_mode=S_IFDIR|0755, st_size=4096, ...}) = 0
lstat64("/tmp/a/b/c/d", {st_mode=S_IFDIR|0755, st_size=4096, ...}) = 0
lstat64("/tmp/a/b/c/d/e", {st_mode=S_IFDIR|0755, st_size=4096, ...}) = 0
lstat64("/tmp/a/b/c/d/e/f", {st_mode=S_IFDIR|0755, st_size=4096, ...}) =
0
lstat64("/tmp/a/b/c/d/e/f/g", {st_mode=S_IFDIR|0755, st_size=4096, ...}) =
0
lstat64("/tmp/a/b/c/d/e/f/g/h", {st_mode=S_IFDIR|0755, st_size=4096, ...})
= 0
lstat64("/tmp/a/b/c/d/e/f/g/h/i", {st_mode=S_IFDIR|0755, st_size=4096,
...}) = 0
lstat64("/tmp/a/b/c/d/e/f/g/h/i/j", {st_mode=S_IFDIR|0755, st_size=4096,
...}) = 0
lstat64("/tmp/a/b/c/d/e/f/g/h/i/j/a.php", {st_mode=S_IFREG|0644,
st_size=11, ...}) = 0
lstat64("/tmp", {st_mode=S_IFDIR|S_ISVTX|0777, st_size=8192, ...}) = 0
lstat64("/tmp/a", {st_mode=S_IFDIR|0755, st_size=4096, ...}) = 0
lstat64("/tmp/a/b", {st_mode=S_IFDIR|0755, st_size=4096, ...}) = 0
lstat64("/tmp/a/b/c", {st_mode=S_IFDIR|0755, st_size=4096, ...}) = 0
lstat64("/tmp/a/b/c/d", {st_mode=S_IFDIR|0755, st_size=4096, ...}) = 0
lstat64("/tmp/a/b/c/d/e", {st_mode=S_IFDIR|0755, st_size=4096, ...}) = 0
lstat64("/tmp/a/b/c/d/e/f", {st_mode=S_IFDIR|0755, st_size=4096, ...}) =
0
lstat64("/tmp/a/b/c/d/e/f/g", {st_mode=S_IFDIR|0755, st_size=4096, ...}) =
0
lstat64("/tmp/a/b/c/d/e/f/g/h", {st_mode=S_IFDIR|0755, st_size=4096, ...})
= 0
lstat64("/tmp/a/b/c/d/e/f/g/h/i", {st_mode=S_IFDIR|0755, st_size=4096,
...}) = 0
lstat64("/tmp/a/b/c/d/e/f/g/h/i/j", {st_mode=S_IFDIR|0755, st_size=4096,
...}) = 0
lstat64("/tmp/a/b/c/d/e/f/g/h/i/j/b.php", {st_mode=S_IFREG|0644,
st_size=7, ...}) = 0
--
Edit bug report at http://bugs.php.net/?id=43864&edit=1
--
Try a CVS snapshot (PHP 4.4):
http://bugs.php.net/fix.php?id=43864&r=trysnapshot44
Try a CVS snapshot (PHP 5.2):
http://bugs.php.net/fix.php?id=43864&r=trysnapshot52
Try a CVS snapshot (PHP 5.3):
http://bugs.php.net/fix.php?id=43864&r=trysnapshot53
Try a CVS snapshot (PHP 6.0):
http://bugs.php.net/fix.php?id=43864&r=trysnapshot60
Fixed in CVS: http://bugs.php.net/fix.php?id=43864&r=fixedcvs
Fixed in release:
http://bugs.php.net/fix.php?id=43864&r=alreadyfixed
Need backtrace: http://bugs.php.net/fix.php?id=43864&r=needtrace
Need Reproduce Script: http://bugs.php.net/fix.php?id=43864&r=needscript
Try newer version: http://bugs.php.net/fix.php?id=43864&r=oldversion
Not developer issue: http://bugs.php.net/fix.php?id=43864&r=support
Expected behavior: http://bugs.php.net/fix.php?id=43864&r=notwrong
Not enough info:
http://bugs.php.net/fix.php?id=43864&r=notenoughinfo
Submitted twice:
http://bugs.php.net/fix.php?id=43864&r=submittedtwice
register_globals: http://bugs.php.net/fix.php?id=43864&r=globals
PHP 3 support discontinued: http://bugs.php.net/fix.php?id=43864&r=php3
Daylight Savings: http://bugs.php.net/fix.php?id=43864&r=dst
IIS Stability: http://bugs.php.net/fix.php?id=43864&r=isapi
Install GNU Sed: http://bugs.php.net/fix.php?id=43864&r=gnused
Floating point limitations: http://bugs.php.net/fix.php?id=43864&r=float
No Zend Extensions: http://bugs.php.net/fix.php?id=43864&r=nozend
MySQL Configuration Error: http://bugs.php.net/fix.php?id=43864&r=mysqlcfg
