By the way, I believe Cris's point was that in a real world situation, the
extra time it takes for a function call is negligible in comparison to
everything else (SQL access, startup/shutdown costs, etc.). Obviously, if
you intentionally benchmark one function call vs. two function calls,
you're going to get pretty much 1::2 performance decrease.
Zeev
At 10:25 09-09-01, Zeev Suraski wrote:
>Substituting your favourite function for strlen() will probably not yield
>similar results, though. strlen()'s implementation takes virtually no time.
>
>Also, try defining gstrlen() before you use it. It'd be much faster.
>
>At 05:58 09-09-01, George Schlossnagle wrote:
>>Benchmarking the execution time for a single function call by making a
>>page and request it via b is a pretty flawed method. While it may show
>>that a single aliased call to gettext() doesn't change the execution time
>>of a script by much, it does not say anything about the relative times
>>for execution of a specific function. You should call the function in a
>>type loop and average over many executions. Here's a sample you can try:
>>
>>strlen.php:
>><?
>> $a = 'blah';
>> while($i < 100000) {
>> $b = strlen($a);
>> $i++;
>> }
>>?>
>>
>>gstrlen.php:
>><?
>> $a = 'blah';
>> while($i < 100000) {
>> $b = gstrlen($a);
>> $i++;
>> }
>> function gstrlen($str) {
>> return strlen($str);
>> }
>>?>
>>
>>
>>22:54:00(george@wasabi)[~/src/php-4.0.6/ext]> time php
>>/opt/apache/htdocs/strlen.php
>>X-Powered-By: PHP/4.0.6
>>Content-type: text/html
>>
>>0.840u 0.010s 0:00.85 100.0% 0+0k 0+0io 293pf+0w
>>
>>22:54:17(george@wasabi)[~/src/php-4.0.6/ext]> time php
>>/opt/apache/htdocs/gstrlen.php
>>X-Powered-By: PHP/4.0.6
>>Content-type: text/html
>>
>>1.950u 0.010s 0:01.95 100.5% 0+0k 0+0io 295pf+0w
>>
>>When done often enough, the difference between calling userland functions
>>and builtins is _huge_. Substitute your favorite function in for strlen
>>(I tried a bunch), you'll get similair results. Having to switch
>>executor contexts evertime you call a userland function is really expensive.
>>
>>George
>>
>>
>>
>>
>>On Saturday, September 8, 2001, at 08:07 PM, Cristopher Daniluk wrote:
>>
>>>I feel like you're getting a bit personal here, but I'll refrain from doing
>>>the same and simply provide numbers. This is a demonstration to prove purely
>>>the overhead of going into a userspace function that calls an internal
>>>versus calling the internal directly. Obviously this isn't scientific, but
>>>that's not my goal.
>>>
>>>3 scripts were created. First called _(""). Second defined a function as
>>>follows:
>>>
>>>function b($str) { return gettext($str); }
>>>
>>>Third b("") instead of _("") - note the second one was created just to try
>>>and normalize out any deviance from parsing the new function.
>>>
>>>Apache Bench was run at 1000 queries to give enough performance to
>>>illustrate a significant deviance. A concurrency of 10 and 100 were used.
>>>Each set was run 3 times and averages were taken to normalize outside
>>>factors. Tests were run randomly at various times throughout the last hour,
>>>to reduce the effect of foreign elements.
>>>
>>>First Test (using _)
>>>Concurrency 10: 50.24/50.23/57.43 = 52.63
>>>Concurrency 100: 44.58/46.59/44.53 = 46.23
>>>
>>>Second Test (defining b)
>>>Concurrency 10: 55.05/56.19/50.55 = 53.93
>>>Concurrency 100: 45.65/47.06/45.71 = 46.12
>>>
>>>Third Test (using b)
>>>Concurrency 10: 55.16/55.82/52.16 = 54.38
>>>Concurrency 100: 46.74/46.39/47.19 = 46.77
>>>
>>>I really truly and with all my heart believe that if simply calling a user
>>>created function could drop performance by 25%, PHP would not be a viable
>>>language. Whether my results are accurate findings or not, Rasmus's
>>>demonstration of a 26.3% performance decrease by CALLING A FUNCTION is a lot
>>>to swallow!
>>>
>>>Oh, and I'll refrain from making the muse that the latter test was faster.
>>>
>>>Having the user make their own function may not be the right solution for
>>>this problem, but its phenomenally silly to argue that it would have a large
>>>performance impact!
>>>
>>>Regards,
>>>
>>>
>>>Cristopher Daniluk
>>>President & CEO
>>>email: [EMAIL PROTECTED]
>>>direct: 330/530-2373
>>>
>>>Digital Services Network, Inc
>>>Unleashing Your Potential
>>>voice: 800/845-4822
>>>web: http://www.dsnet.net/
>>>
>>>
>>>-----Original Message-----
>>>From: Chuck Hagenbuch [mailto:[EMAIL PROTECTED]]
>>>Sent: Saturday, September 08, 2001 7:23 PM
>>>To: [EMAIL PROTECTED]
>>>Cc: 'PHP Developer List'
>>>Subject: RE: [PHP-DEV] Woah
>>>
>>>
>>>Quoting Cristopher Daniluk <[EMAIL PROTECTED]>:
>>>
>>>>Agreed, but is the speed loss really worth crying about?
>>>
>>>Obviously not to you, but I'm pretty sure you came down in the category of
>>>people who'd never used gettext.
>>>
>>>>It is negligible calling a userspace function versus an internal compared
>>>to
>>>>the greater work that the typical PHP script does.
>>>
>>>What authority do you have to make this statement? Rasmus posted numbers.
>>>Where
>>>are yours?
>>>
>>>-chuck
>>>
>>>--
>>>Charles Hagenbuch, <[EMAIL PROTECTED]>
>>>Some fallen angels have their good reasons.
>>>
>>>--
>>>PHP Development Mailing List <http://www.php.net/>
>>>To unsubscribe, e-mail: [EMAIL PROTECTED]
>>>For additional commands, e-mail: [EMAIL PROTECTED]
>>>To contact the list administrators, e-mail: [EMAIL PROTECTED]
>><Attachment missing>> --
>>>PHP Development Mailing List <http://www.php.net/>
>>>To unsubscribe, e-mail: [EMAIL PROTECTED]
>>>For additional commands, e-mail: [EMAIL PROTECTED]
>>>To contact the list administrators, e-mail: [EMAIL PROTECTED]
>>
>>
>>Benchmarking the execution time for a single function call by making a
>>page and request it via b is a pretty flawed method. While it may show
>>that a single aliased call to gettext() doesn't change the execution time
>>of a script by much, it does not say anything about the relative times
>>for execution of a specific function. You should call the function in a
>>type loop and average over many executions. Here's a sample you can try:
>>
>>strlen.php:
>><?
>> $a = 'blah';
>> while($i < 100000) {
>> $b = strlen($a);
>> $i++;
>> }
>>?>
>>
>>gstrlen.php:
>><?
>> $a = 'blah';
>> while($i < 100000) {
>> $b = gstrlen($a);
>> $i++;
>> }
>> function gstrlen($str) {
>> return strlen($str);
>> }
>>?>
>>
>>
>>22:54:00(george@wasabi)[~/src/php-4.0.6/ext]> time php
>>/opt/apache/htdocs/strlen.php
>>X-Powered-By: PHP/4.0.6
>>Content-type: text/html
>>
>>0.840u 0.010s 0:00.85 100.0% 0+0k 0+0io 293pf+0w
>>
>>22:54:17(george@wasabi)[~/src/php-4.0.6/ext]> time php
>>/opt/apache/htdocs/gstrlen.php
>>X-Powered-By: PHP/4.0.6
>>Content-type: text/html
>>
>>1.950u 0.010s 0:01.95 100.5% 0+0k 0+0io 295pf+0w
>>
>>When done often enough, the difference between calling userland functions
>>and builtins is _huge_. Substitute your favorite function in for strlen
>>(I tried a bunch), you'll get similair results. Having to switch
>>executor contexts evertime you call a userland function is really expensive.
>>
>>George
>>
>>
>>
>>
>>On Saturday, September 8, 2001, at 08:07 PM, Cristopher Daniluk wrote:
>>
>>>I feel like you're getting a bit personal here, but I'll refrain from doing
>>>the same and simply provide numbers. This is a demonstration to prove purely
>>>the overhead of going into a userspace function that calls an internal
>>>versus calling the internal directly. Obviously this isn't scientific, but
>>>that's not my goal.
>>>
>>>3 scripts were created. First called _(""). Second defined a function as
>>>follows:
>>>
>>>function b($str) { return gettext($str); }
>>>
>>>Third b("") instead of _("") - note the second one was created just to try
>>>and normalize out any deviance from parsing the new function.
>>>
>>>Apache Bench was run at 1000 queries to give enough performance to
>>>illustrate a significant deviance. A concurrency of 10 and 100 were used.
>>>Each set was run 3 times and averages were taken to normalize outside
>>>factors. Tests were run randomly at various times throughout the last hour,
>>>to reduce the effect of foreign elements.
>>>
>>>First Test (using _)
>>>Concurrency 10: 50.24/50.23/57.43 = 52.63
>>>Concurrency 100: 44.58/46.59/44.53 = 46.23
>>>
>>>Second Test (defining b)
>>>Concurrency 10: 55.05/56.19/50.55 = 53.93
>>>Concurrency 100: 45.65/47.06/45.71 = 46.12
>>>
>>>Third Test (using b)
>>>Concurrency 10: 55.16/55.82/52.16 = 54.38
>>>Concurrency 100: 46.74/46.39/47.19 = 46.77
>>>
>>>I really truly and with all my heart believe that if simply calling a user
>>>created function could drop performance by 25%, PHP would not be a viable
>>>language. Whether my results are accurate findings or not, Rasmus's
>>>demonstration of a 26.3% performance decrease by CALLING A FUNCTION is a lot
>>>to swallow!
>>>
>>>Oh, and I'll refrain from making the muse that the latter test was faster.
>>>
>>>Having the user make their own function may not be the right solution for
>>>this problem, but its phenomenally silly to argue that it would have a large
>>>performance impact!
>>>
>>>Regards,
>>>
>>>
>>>Cristopher Daniluk
>>>President & CEO
>>>email: [EMAIL PROTECTED]
>>>direct: 330/530-2373
>>>
>>>Digital Services Network, Inc
>>>Unleashing Your Potential
>>>voice: 800/845-4822
>>>web: http://www.dsnet.net/
>>>
>>>
>>>-----Original Message-----
>>>From: Chuck Hagenbuch [mailto:[EMAIL PROTECTED]]
>>>Sent: Saturday, September 08, 2001 7:23 PM
>>>To: [EMAIL PROTECTED]
>>>Cc: 'PHP Developer List'
>>>Subject: RE: [PHP-DEV] Woah
>>>
>>>
>>>Quoting Cristopher Daniluk <[EMAIL PROTECTED]>:
>>>
>>>>Agreed, but is the speed loss really worth crying about?
>>>
>>>Obviously not to you, but I'm pretty sure you came down in the category of
>>>people who'd never used gettext.
>>>
>>>>It is negligible calling a userspace function versus an internal compared
>>>to
>>>>the greater work that the typical PHP script does.
>>>
>>>What authority do you have to make this statement? Rasmus posted numbers.
>>>Where
>>>are yours?
>>>
>>>-chuck
>>>
>>>--
>>>Charles Hagenbuch, <[EMAIL PROTECTED]>
>>>Some fallen angels have their good reasons.
>>>
>>>--
>>>PHP Development Mailing List <http://www.php.net/>
>>>To unsubscribe, e-mail: [EMAIL PROTECTED]
>>>For additional commands, e-mail: [EMAIL PROTECTED]
>>>To contact the list administrators, e-mail: [EMAIL PROTECTED]
>>
>>
>>
>>>--
>>>PHP Development Mailing List <http://www.php.net/>
>>>To unsubscribe, e-mail: [EMAIL PROTECTED]
>>>For additional commands, e-mail: [EMAIL PROTECTED]
>>>To contact the list administrators, e-mail: [EMAIL PROTECTED]
>
>
>--
>PHP Development Mailing List <http://www.php.net/>
>To unsubscribe, e-mail: [EMAIL PROTECTED]
>For additional commands, e-mail: [EMAIL PROTECTED]
>To contact the list administrators, e-mail: [EMAIL PROTECTED]
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