Newsgroups: php.internals
Path: news.php.net
Xref: news.php.net php.internals:33873
Mailing-List: contact internals-help@lists.php.net; run by ezmlm
Message-ID: <EF.AA.51488.77DFA574@pb1.pair.com>
To: internals@lists.php.net
Date: Sat, 08 Dec 2007 20:22:32 +0000
Reply-To: nrixham@gmail.com
User-Agent: Thunderbird 2.0.0.9 (Windows/20071031)
MIME-Version: 1.0
References: <698DE66518E7CA45812BD18E807866CEF88FDD@us-ex1.zend.net> <D37F0F93-EA19-4178-BCEE-91A7C36A7650@prohost.org> <7d5a202f0712031900i386f8964s675da26cc93af3fe@mail.gmail.com> <47550FAB.30002@daylessday.org> <698DE66518E7CA45812BD18E807866CEF890ED@us-ex1.zend.net> <475578BE.40908@daylessday.org> <4755A797.1020905@lerdorf.com> <009001c836ae$4ba0add0$e2e20970$@mcnaught@synergy8.com> <4755B310.9070603@lerdorf.com> <4755B55A.1030708@zend.com> <4755B61A.2000803@lerdorf.com> <50921.98.193.37.55.1197080740.squirrel@www.l-i-e.com> <FB18DCDE-5A7A-4181-86C9-820F24E09AC5@prohost.org> <698DE66518E7CA45812BD18E807866CE0100C741@us-ex1.zend.net>
In-Reply-To: <698DE66518E7CA45812BD18E807866CE0100C741@us-ex1.zend.net>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Content-Transfer-Encoding: 7bit
Subject: Re: [PHP-DEV] Garbage collector patch
From: nrixham@gmail.com (Nathan Rixham)

Sorry to intrude on this one!

It seems that some real hard work has gone into this, and a big thanks 
from the community for all your hard work.

Can the gc patch feasibly be improved any more? If so surely the time 
scales involved with improving further would mean it'd miss the boat for 
a 5.3.x release..?

Real-life use of PHP has to be the foremost concideration; in the 
production environment, especially on server farms and shared hosts, how 
many of them are going to be upgraded to 5.3 anyways, and when so, not 
for a long time (sadly)! 4 bytes vs the earlier 12 bytes is a 
significant improvement, and much as this may seem a terrible thing to say..

Roll it out in 5.3, turned on by default (with option to disable at 
compile time) - that's your test right there, if there are problems then 
have it disabled by default in the subsequent minor release.

My only (and major) concern as an end developer is the 5% slowdown and 
3% memory overhead, exactly what benefit am I as an end developer going 
recieve for this?

Andi started this series with : "On one hand I think now the effort has 
been made it's a good thing to offer it as part of PHP"; and I for one 
agree, with the emphasis on *offer*.

Many Regards & Apologies for the intrusion.

Nathan

Andi Gutmans wrote:
> Hi Ilia,
> 
> I suggest more people test the performance difference because as you can
> see for us it was negligible. From my experience you see bigger
> deviations just by moving kernels, compilers, and even small patches
> which affect where in memory the code segments sit, etc...
> Maybe some people here who have performance harnesses (I'm sure Yahoo!
> has one) could test it too.
> 
> Andi
> 
>> -----Original Message-----
>> From: Ilia Alshanetsky [mailto:ilia@prohost.org]
>> Sent: Saturday, December 08, 2007 9:35 AM
>> To: ceo@l-i-e.com
>> Cc: Rasmus Lerdorf; Stas Malyshev; scott.mcnaught@synergy8.com;
> 'Antony
>> Dovgal'; Andi Gutmans; 'Cristian Rodriguez'; internals@lists.php.net
>> Subject: Re: [PHP-DEV] Garbage collector patch
>>
>> Richard,
>>
>> zval is such a common PHP structure that in a scope of a single script
>> (even a trivial one) you'd have thousands of them. Therefor even an
>> extra 4 bytes matter, and for people with large application it would
>> matter even more. I wish the patch was such that it had no impact on
>> the people who don't need it, but the reality is that for anyone who
>> does not need gc cycles, it'll be a performance (speed & memory)
>> penalty. This is why I had intimately suggested making it a compile
>> time, configuration option.
>>
>>
>> On 7-Dec-07, at 9:25 PM, Richard Lynch wrote:
>>
>>> On Tue, December 4, 2007 2:18 pm, Rasmus Lerdorf wrote:
>>>> Stanislav Malyshev wrote:
>>>>>> 1. Always compile it in but leave undocumented #ifdefs in place
>> for
>>>>>> performance freaks.  Those same performance freaks aren't going
> to
>>>>>> care
>>>>>> about the binary compatibility issue since they are the same
>> people
>>>>>> who
>>>>>> build all their own stuff.
>>>>> Note that breaking BC is not only about performance - one your
>> build
>>>>> is
>>>>> not the same as mainstream PHP, you can't use any binary extension
>>>>> which
>>>>> would do anything non-performance-related - like interfacing some
>>>>> external system/library, debugging, profiling, testing, security
>> and
>>>>> so on.
>>>>> Any commercial module won't be available for the user of this
>>>>> switch,
>>>>> and all open-source modules one'd have to build by oneself, which
>>>>> may be
>>>>> serious maintenance issue. I know there are a bunch of companies
>>>>> that
>>>>> compile PHP with their own options but still use commercial
>> modules,
>>>>> including both performance and non-performance ones. They couldn't
>>>>> use
>>>>> this compile switch.
>>>> Yes, I know what binary compatibility means.
>>> Call me crazy, but...
>>>
>>> Would it be possible to hard-code the bit that adds the 4 bytes to
>> the
>>> zval, but make the execution bit a flag so that binary compatibility
>>> is always there, but the executable code that does the GC can come
> or
>>> go as needed?...
>>>
>>> Or am I just talking nonsense due to ignorance?
>>>
>>> --
>>> Some people have a "gift" link here.
>>> Know what I want?
>>> I want you to buy a CD from some indie artist.
>>> http://cdbaby.com/from/lynch
>>> Yeah, I get a buck. So?
>>>
>>> --
>>> PHP Internals - PHP Runtime Development Mailing List
>>> To unsubscribe, visit: http://www.php.net/unsub.php
>>>
>> Ilia Alshanetsky
>>
>>
>>