Hi, I don't have access and I don't need to do the changes myself, but if you prefer it, I will (provided I get access of course).
Ron "Marcus Boerger" <[EMAIL PROTECTED]> wrote in message news:[EMAIL PROTECTED] > Hello Ron, > > that stuff is only used in edgcases however it is more of a fix than an > optimization. Do you have access and want to do the changes yourself? > > regards > marcus > > Monday, March 13, 2006, 10:08:30 PM, you wrote: > > > Hi, > > > If you're even interested in the tinyest of optimizations, you may wanna > > read this. I was just going through the php code. I'm not familiar with it > > at all, so I don't know which functions are the bottlenecks, so I can't help > > in optimizing the big picture. But I had little else to do right now, so I > > figured I'd just browse around through the files to see if I could notice > > any local speedups. So really, the things I lay out here are probably > > futile, but who knows. > > > > ----- > > > I found that for example the function php_stream_memory_seek() in > > main/streams/memory.c contains a whole bunch of return statements. I found > > that it can be (you can benchmark this) slightly faster to do this: > > > int func(int p) > > { > > int result = 0; > > > switch (p) > > { > > case 0: result = 1; break; > > case 1: result = -4; break; > > case 2: result = 15; break; > > } > > return result; > > } > > > instead of this: > > > int func(int p) > > { > > switch (p) > > { > > case 0: return 1; > > case 1: return -4; > > case 2: return 15; > > } > > return 0; > > } > > > This is correct with 'gcc foo.c' as well as with 'gcc -O2 foo.c'. The > > difference is slight, and if it's too tiny, just ignore it this message. > > > Perhaps some functions that php relies on heavily may benefit from this > > though (but I wouldn't know which ones those would be). > > > ----- > > > Also, I noticed that in php_start_ob_buffer() in main/output.c, and probably > > in more functions integers are divided by 2 by doing: > > result = intvar / 2; > > while it is about 20% faster (even with -O2) to do this: > > result = intvar >> 1; > > > ----- > > > A minor thing I noticed (nothing to speed up here though) is an unused > > variable 'i' in insertionsort() in main/mergesort.c (weird that this never > > showed up as a compiler warning). Or does the defined TSRMLS_CC depend on > > the existance of an integer called 'i'? Pretty unlikely to me. > > > ----- > > > Why is CONTEXT_TYPE_IMAGE_GIF in main/logos.h defined as "Content-Type: > > image/gif" with 2 spaces between "Content-Type" and "image/gif"? > > > ----- > > > In sapi/apache/mod_php5.c in the function php_apache_log_message(), > > > Why are these 2 calls: > > > fprintf(stderr, "%s", message); > > fprintf(stderr, "\n"); > > > instead of 1 call: > > > fprintf(stderr, "%s\n", message); > > > ----- > > > In sapi/apache/mod_php5.c in the function php_apache_flag_handler_ex(), > > > the original: > > if (!strcasecmp(arg2, "On") || (arg2[0] == '1' && arg2[1] == '\0')) { > > bool_val[0] = '1'; > > } else { > > bool_val[0] = '0'; > > } > > > is over 5 times slower than: > > > if (((arg2[0] == 'O' || arg2[0] == 'o') && (arg2[1] == 'n' || arg2[1] == > > 'N') && (arg2[2] == '\0')) || (arg2[0] == '1' && arg2[1] == '\0')) { > > bool_val[0] = '1'; > > } else { > > bool_val[0] = '0'; > > } > > > ----- > > > > Like I said, these are extremely tiny things, so please ignore it if it's > > too futile :) Nonetheless, if this turns out to be appreciated information, > > I'll continue the hunt. > > > Good luck optimizing, > > > Ron > > > > "Rasmus Lerdorf" <[EMAIL PROTECTED]> wrote in message > > news:[EMAIL PROTECTED] > >> We have a bit of a performance disconnect between 4.4 and 5.1 still. I > >> was doing some benchmarking today just as a sanity check on some APC > >> work I have been doing lately and came up with this: > >> > >> http://lerdorf.com/php/bm.html > >> > >> You can ignore the apc/eaccelerator stuff. Those numbers are not > >> surprising. The surprising number to me is how much faster 4.4 still is. > >> > >> The graph labels are slightly off. The 0, 5 and 10 includes should > >> really be 1, 6 and 11. The actual benchmark code is here: > >> > >> http://www.php.net/~rasmus/bm.tar.gz > >> > >> Tested on a Linux 2.6 Ubuntu box on an AMD chip (syscalls are cheap > >> there) with current PHP_4_4 and PHP_5_1 checkouts. Was also testing > >> 5.1.2 to see the effect of getting rid of that uncached realpath call. > >> > >> As far as I can tell auto_globals_jit isn't working at all, but I > >> eliminated that by doing variables_order = GP for these benchmarks. > >> Even so, the request_startup is significantly more expensive in 5.1. > >> > >> Here are callgrind dumps for each. Load them up with kcachegrind and > >> browse around: > >> > >> PHP 4.4 http://www.php.net/~rasmus/callgrind.out.1528.gz > >> PHP 5.1 http://www.php.net/~rasmus/callgrind.out.1488.gz > >> > >> Each of these is 1000 requests against the top.php and 4top.php scripts. > >> from bm.tar.gz. If you start at the > >> > >> The script is trivial and looks like this: > >> > >> <html> > >> <?php > >> $base_dir = '/var/www/bm/'; > >> include $base_dir . 'config.inc'; > >> > >> function top_func($arg) { > >> $b = $arg.$arg; > >> echo $b; > >> } > >> class top_class { > >> private $prop; > >> function __construct($arg) { > >> $this->prop = $arg; > >> } > >> function getProp() { > >> return $this->prop; > >> } > >> function setProp($arg) { > >> $this->prop = strtolower($arg); > >> } > >> } > >> > >> top_func('foo'); > >> $a = new top_class('bar'); > >> echo $a->getProp(); > >> $a->setProp("AbCdEfG"); > >> echo $a->getProp(); > >> echo <<<EOB > >> The database is {$config['db']} > >> and the user is {$config['db_user']} > >> > >> EOB; > >> ?> > >> </html> > >> > >> and config.inc is: > >> > >> <?php > >> $config = array( > >> 'db' => 'mysql', > >> 'db_user' => 'www', > >> 'db_pwd' => 'foobar', > >> 'config1' => 123, > >> 'config2' => 456, > >> 'config3' => 789, > >> 'sub1' => array(1,2,3,4,5,6,7,8,9,10), > >> 'sub2' => > > array("abc","def","ghi","jkl","mno","pqr","stu","vwx","yz") > >> ); > >> ?> > >> > >> 4top.php is identical except for the class definition being PHP 4-style > >> instead. As in no private and a PHP 4 constructor. Otherwise it is > >> identical. > >> > >> I have some ideas for things we can speed up in 5.1. Like, for example, > >> we should add the ap_add_common_vars() and ap_add_cgi_vars() to the jit > >> mechanism. There isn't much point filling these in unless the script > >> tries to get them. the ap_add_common_vars() call is extremely expensive > >> since it does a qsort with a comparison function that uses strcasecmp. > >> Of course, this same optimization can be done in 4.4. > >> > >> If you know your way around kcachegrind, load up the two callgrind files > >> and see what stands out for you. As far as I can tell, while we can do > >> some tricks to speed up various helper bits, the slowdown is coming from > >> the executor trashing its cache lines. > >> > >> -Rasmus > > > > > Best regards, > Marcus -- PHP Internals - PHP Runtime Development Mailing List To unsubscribe, visit: http://www.php.net/unsub.php
