17 years ago by Andi Gutmans — view source

unread

Hi all,

Was hoping to send this off earlier but I was travelling for the past
week and had very limited email access.

As promised in the past few weeks we have spent a significant amount of
time in reviewing the garbage collector work and testing it in our
performance lab. Dmitry has been exchanging ideas and patches with David
Wang during this time. Suffice to say that as I've mentioned in the
past, memory management is an extremely sensitive piece of PHP, which is
why it was important for us to review this work in great depth before
committing it to the code base.

The updated patch still retains the same algorithm as David's original
implementation however the data structures have been changed in order to
work faster and use less memory.

The revised patch has the following advantages:

It fixes several crash bugs
Enhances performance by removing several unnecessary checks
The memory overhead was reduced (from 12 to 4 bytes for each
heap-allocated zval)
The speed of "clean" PHP code (code that doesn't create cycles) was
improved
Additional test cases were created

The end result is a more stable and faster GC patch. That said we have
yet to find real-life applications that create significant cycles which
would benefit from this patch. In fact as you'll see from the results
our tests show an increase in maximum memory use and slower execution
(to be fair they are marginal).

We have tested both PHP_5_3 without any patches, the original patch and
the new patch.

The following table shows execution time (seconds for N requests) and
slowdown.

PHP_5_3

Original GC patch

Current GC patch

slowdown

bench

11,550

12,310

6,58%

12,170

5,37%

hello

8,781

8,852

0,81%

8,813

0,36%

xoops

128,500

135,100

5,14%

130,200

1,32%

static

18,540

20,840

12,41%

18,920

2,05%

qdig

29,320

30,270

3,24%

29,610

0,99%

qdig2

13,960

14,100

1,00%

14,090

0,93%

The next table shows memory usage in MB and overhead

PHP_5_3

Original GC patch

Current GC patch

overhead

hello

13,750

13,945

1,42%

13,765

0,11%

xoops

18,036

18,636

3,33%

18,568

2,95%

static

15,300

16,000

4,58%

15,308

0,05%

qdig

14,820

15,008

1,27%

14,828

0,05%

qdig2

14,824

15,012

1,27%

14,838

0,09%

To summarize the patch lead to approx. 5% slowdown and 3% memory
overhead for typical applications (as always, you mileage may vary
depending on your system's architecture and OS although my guesstimate
is that you will see even worse results in a 64bit environment). We also
tested SugarCRM to get another sanity for these results and we got
similar results.

I am not quite sure where this leaves us with this patch. On one hand I
think now the effort has been made it's a good thing to offer it as part
of PHP. The downside is of course some performance degradation and
possible instabilities as this patch continues to stabilize (it took
about two releases for us to stabilize the Zend Memory Manager even
after in-depth testing due to edge cases in allocation patterns and
various extensions, etc...).I'd be surprised if our team has found all
possible bugs.

Personally I think the decision should be either in or out. Adding this
as a compile option is not a good idea as it would create binary
compatibility issues and would be a pain for the community. I think my
inclination is to commit the patch, not have it #ifdef'ed but always
compiled but to have the garbage collection itself turned off by default
(mainly for stability reasons. Note: the increased memory footprint and
performance loss also exists with the collection itself turned off). We
can turn it on when we're in dev for snapshots so that we iron out bugs.
That said, as you can see from the results most people and real-life
applications will be worse off than today.

Thanks to David & Dmitry for working hard on this (and everyone else who
contributed).

The stage is open for ideas/thoughts/suggestions J

Andi

17 years ago by Daniel Brown — view source

unread

Hi all,

Was hoping to send this off earlier but I was travelling for the past
week and had very limited email access.

As promised in the past few weeks we have spent a significant amount of
time in reviewing the garbage collector work and testing it in our
performance lab. Dmitry has been exchanging ideas and patches with David
Wang during this time. Suffice to say that as I've mentioned in the
past, memory management is an extremely sensitive piece of PHP, which is
why it was important for us to review this work in great depth before
committing it to the code base.

The updated patch still retains the same algorithm as David's original
implementation however the data structures have been changed in order to
work faster and use less memory.

The revised patch has the following advantages:

It fixes several crash bugs

Enhances performance by removing several unnecessary checks

The memory overhead was reduced (from 12 to 4 bytes for each
heap-allocated zval)

The speed of "clean" PHP code (code that doesn't create cycles) was
improved

Additional test cases were created

The end result is a more stable and faster GC patch. That said we have
yet to find real-life applications that create significant cycles which
would benefit from this patch. In fact as you'll see from the results
our tests show an increase in maximum memory use and slower execution
(to be fair they are marginal).

We have tested both PHP_5_3 without any patches, the original patch and
the new patch.

The following table shows execution time (seconds for N requests) and
slowdown.
    PHP_5_3
Original GC patch

Current GC patch

slowdown

slowdown

bench

11,550

12,310

6,58%

12,170

5,37%

hello

8,781

8,852

0,81%

8,813

0,36%

xoops

128,500

135,100

5,14%

130,200

1,32%

static

18,540

20,840

12,41%

18,920

2,05%

qdig

29,320

30,270

3,24%

29,610

0,99%

qdig2

13,960

14,100

1,00%

14,090

0,93%

The next table shows memory usage in MB and overhead
    PHP_5_3
Original GC patch

Current GC patch

overhead

overhead

hello

13,750

13,945

1,42%

13,765

0,11%

xoops

18,036

18,636

3,33%

18,568

2,95%

static

15,300

16,000

4,58%

15,308

0,05%

qdig

14,820

15,008

1,27%

14,828

0,05%

qdig2

14,824

15,012

1,27%

14,838

0,09%

To summarize the patch lead to approx. 5% slowdown and 3% memory
overhead for typical applications (as always, you mileage may vary
depending on your system's architecture and OS although my guesstimate
is that you will see even worse results in a 64bit environment). We also
tested SugarCRM to get another sanity for these results and we got
similar results.

I am not quite sure where this leaves us with this patch. On one hand I
think now the effort has been made it's a good thing to offer it as part
of PHP. The downside is of course some performance degradation and
possible instabilities as this patch continues to stabilize (it took
about two releases for us to stabilize the Zend Memory Manager even
after in-depth testing due to edge cases in allocation patterns and
various extensions, etc...).I'd be surprised if our team has found all
possible bugs.

Personally I think the decision should be either in or out. Adding this
as a compile option is not a good idea as it would create binary
compatibility issues and would be a pain for the community. I think my
inclination is to commit the patch, not have it #ifdef'ed but always
compiled but to have the garbage collection itself turned off by default
(mainly for stability reasons. Note: the increased memory footprint and
performance loss also exists with the collection itself turned off). We
can turn it on when we're in dev for snapshots so that we iron out bugs.
That said, as you can see from the results most people and real-life
applications will be worse off than today.

Thanks to David & Dmitry for working hard on this (and everyone else who
contributed).

The stage is open for ideas/thoughts/suggestions J

Andi

Andi,

I don't know about how it worked for anyone else, but the tables

didn't display properly on Gmail, so I had a hard time keeping up with
the performance differences. If you have this in a separate file,
could you send it to me as an attachment? I have a few real-world
benchmarks I'd like to try from the angle of the shared-webhost
industry (lots of users with horrible code running simultaneously, et
cetera) which I'd like to compare to your notes.

Thanks.

--
Daniel P. Brown
[office] (570-) 587-7080 Ext. 272
[mobile] (570-) 766-8107

If at first you don't succeed, stick to what you know best so that you
can make enough money to pay someone else to do it for you.

17 years ago by Markus Fischer — view source

unread

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

Hi,

Daniel Brown wrote:

I don't know about how it worked for anyone else, but the tables
didn't display properly on Gmail, so I had a hard time keeping up with
the performance differences. If you have this in a separate file,
could you send it to me as an attachment?

Same problem, all in one row, to "table" to read. We're having
non-apache application which run up to one hour to do their task and I
think our QA can test the new GC there (and memory consumption is an
issue there definitely).

thanks
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.6 (MingW32)
Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org

iD8DBQFHVHWh1nS0RcInK9ARAmPlAJ9XnOzFmLSl8qDxY5bLBfJBcmgqRACfZnsn
R3cFSHfkMpoffq+f5vMxI3g=
=OkMW
-----END PGP SIGNATURE

17 years ago by Andi Gutmans — view source

unread

That'd be great.
Dmitry, David, can you please send the updated patch to the list?

Andi

-----Original Message-----
From: Markus Fischer [mailto:markus@fischer.name]
Sent: Monday, December 03, 2007 1:31 PM
To: Daniel Brown
Cc: Andi Gutmans; internals@lists.php.net
Subject: Re: [PHP-DEV] Garbage collector patch

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

Hi,

Daniel Brown wrote:
I don't know about how it worked for anyone else, but the tables
didn't display properly on Gmail, so I had a hard time keeping up
with
the performance differences. If you have this in a separate file,
could you send it to me as an attachment?
Same problem, all in one row, to "table" to read. We're having
non-apache application which run up to one hour to do their task and I
think our QA can test the new GC there (and memory consumption is an
issue there definitely).

thanks
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.6 (MingW32)
Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org

iD8DBQFHVHWh1nS0RcInK9ARAmPlAJ9XnOzFmLSl8qDxY5bLBfJBcmgqRACfZnsn
R3cFSHfkMpoffq+f5vMxI3g=
=OkMW
-----END PGP SIGNATURE

17 years ago by Dmitry Stogov — view source

unread

attached.

Dmitry.

Andi Gutmans wrote:

That'd be great.
Dmitry, David, can you please send the updated patch to the list?

Andi
-----Original Message-----
From: Markus Fischer [mailto:markus@fischer.name]
Sent: Monday, December 03, 2007 1:31 PM
To: Daniel Brown
Cc: Andi Gutmans; internals@lists.php.net
Subject: Re: [PHP-DEV] Garbage collector patch

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

Hi,

Daniel Brown wrote:
I don't know about how it worked for anyone else, but the tables
didn't display properly on Gmail, so I had a hard time keeping up
with
the performance differences. If you have this in a separate file,
could you send it to me as an attachment?
Same problem, all in one row, to "table" to read. We're having
non-apache application which run up to one hour to do their task and I
think our QA can test the new GC there (and memory consumption is an
issue there definitely).
thanks
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.6 (MingW32)
Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org

iD8DBQFHVHWh1nS0RcInK9ARAmPlAJ9XnOzFmLSl8qDxY5bLBfJBcmgqRACfZnsn
R3cFSHfkMpoffq+f5vMxI3g=
=OkMW
-----END PGP SIGNATURE

17 years ago by Andi Gutmans — view source

unread

Sorry about that. Does the attached PDFed screenshot work for you?

Andi

-----Original Message-----
From: Daniel Brown [mailto:parasane@gmail.com]
Sent: Monday, December 03, 2007 1:21 PM
To: Andi Gutmans
Cc: internals@lists.php.net
Subject: Re: [PHP-DEV] Garbage collector patch
Hi all,

Was hoping to send this off earlier but I was travelling for the
past
week and had very limited email access.

As promised in the past few weeks we have spent a significant amount
of
time in reviewing the garbage collector work and testing it in our
performance lab. Dmitry has been exchanging ideas and patches with
David
Wang during this time. Suffice to say that as I've mentioned in the
past, memory management is an extremely sensitive piece of PHP,
which
is
why it was important for us to review this work in great depth
before
committing it to the code base.

The updated patch still retains the same algorithm as David's
original
implementation however the data structures have been changed in
order
to
work faster and use less memory.

The revised patch has the following advantages:

It fixes several crash bugs

Enhances performance by removing several unnecessary checks

The memory overhead was reduced (from 12 to 4 bytes for each
heap-allocated zval)

The speed of "clean" PHP code (code that doesn't create cycles)
was
improved

Additional test cases were created

The end result is a more stable and faster GC patch. That said we
have
yet to find real-life applications that create significant cycles
which
would benefit from this patch. In fact as you'll see from the
results
our tests show an increase in maximum memory use and slower
execution
(to be fair they are marginal).

We have tested both PHP_5_3 without any patches, the original patch
and
the new patch.

The following table shows execution time (seconds for N requests)
and
slowdown.
    PHP_5_3
Original GC patch

Current GC patch

slowdown

slowdown

bench

11,550

12,310

6,58%

12,170

5,37%

hello

8,781

8,852

0,81%

8,813

0,36%

xoops

128,500

135,100

5,14%

130,200

1,32%

static

18,540

20,840

12,41%

18,920

2,05%

qdig

29,320

30,270

3,24%

29,610

0,99%

qdig2

13,960

14,100

1,00%

14,090

0,93%

The next table shows memory usage in MB and overhead
    PHP_5_3
Original GC patch

Current GC patch

overhead

overhead

hello

13,750

13,945

1,42%

13,765

0,11%

xoops

18,036

18,636

3,33%

18,568

2,95%

static

15,300

16,000

4,58%

15,308

0,05%

qdig

14,820

15,008

1,27%

14,828

0,05%

qdig2

14,824

15,012

1,27%

14,838

0,09%

To summarize the patch lead to approx. 5% slowdown and 3% memory
overhead for typical applications (as always, you mileage may vary
depending on your system's architecture and OS although my
guesstimate
is that you will see even worse results in a 64bit environment). We
also
tested SugarCRM to get another sanity for these results and we got
similar results.

I am not quite sure where this leaves us with this patch. On one
hand
I
think now the effort has been made it's a good thing to offer it as
part
of PHP. The downside is of course some performance degradation and
possible instabilities as this patch continues to stabilize (it took
about two releases for us to stabilize the Zend Memory Manager even
after in-depth testing due to edge cases in allocation patterns and
various extensions, etc...).I'd be surprised if our team has found
all
possible bugs.

Personally I think the decision should be either in or out. Adding
this
as a compile option is not a good idea as it would create binary
compatibility issues and would be a pain for the community. I think
my
inclination is to commit the patch, not have it #ifdef'ed but always
compiled but to have the garbage collection itself turned off by
default
(mainly for stability reasons. Note: the increased memory footprint
and
performance loss also exists with the collection itself turned off).
We
can turn it on when we're in dev for snapshots so that we iron out
bugs.
That said, as you can see from the results most people and real-life
applications will be worse off than today.

Thanks to David & Dmitry for working hard on this (and everyone else
who
contributed).

The stage is open for ideas/thoughts/suggestions J

Andi
Andi,

I don't know about how it worked for anyone else, but the tables
didn't display properly on Gmail, so I had a hard time keeping up with
the performance differences. If you have this in a separate file,
could you send it to me as an attachment? I have a few real-world
benchmarks I'd like to try from the angle of the shared-webhost
industry (lots of users with horrible code running simultaneously, et
cetera) which I'd like to compare to your notes.
Thanks.
--
Daniel P. Brown
[office] (570-) 587-7080 Ext. 272
[mobile] (570-) 766-8107

If at first you don't succeed, stick to what you know best so that you
can make enough money to pay someone else to do it for you.

17 years ago by Daniel Brown — view source

unread

That looks great, Andi.

Thanks.

Sorry about that. Does the attached PDFed screenshot work for you?

Andi
-----Original Message-----
From: Daniel Brown [mailto:parasane@gmail.com]
Sent: Monday, December 03, 2007 1:21 PM
To: Andi Gutmans
Cc: internals@lists.php.net
Subject: Re: [PHP-DEV] Garbage collector patch
Hi all,

Was hoping to send this off earlier but I was travelling for the
past
week and had very limited email access.

As promised in the past few weeks we have spent a significant amount
of
time in reviewing the garbage collector work and testing it in our
performance lab. Dmitry has been exchanging ideas and patches with
David
Wang during this time. Suffice to say that as I've mentioned in the
past, memory management is an extremely sensitive piece of PHP,
which
is
why it was important for us to review this work in great depth
before
committing it to the code base.

The updated patch still retains the same algorithm as David's
original
implementation however the data structures have been changed in
order
to
work faster and use less memory.

The revised patch has the following advantages:

It fixes several crash bugs

Enhances performance by removing several unnecessary checks

The memory overhead was reduced (from 12 to 4 bytes for each
heap-allocated zval)

The speed of "clean" PHP code (code that doesn't create cycles)
was
improved

Additional test cases were created

The end result is a more stable and faster GC patch. That said we
have
yet to find real-life applications that create significant cycles
which
would benefit from this patch. In fact as you'll see from the
results
our tests show an increase in maximum memory use and slower
execution
(to be fair they are marginal).

We have tested both PHP_5_3 without any patches, the original patch
and
the new patch.

The following table shows execution time (seconds for N requests)
and
slowdown.
    PHP_5_3
Original GC patch

Current GC patch

slowdown

slowdown

bench

11,550

12,310

6,58%

12,170

5,37%

hello

8,781

8,852

0,81%

8,813

0,36%

xoops

128,500

135,100

5,14%

130,200

1,32%

static

18,540

20,840

12,41%

18,920

2,05%

qdig

29,320

30,270

3,24%

29,610

0,99%

qdig2

13,960

14,100

1,00%

14,090

0,93%

The next table shows memory usage in MB and overhead
    PHP_5_3
Original GC patch

Current GC patch

overhead

overhead

hello

13,750

13,945

1,42%

13,765

0,11%

xoops

18,036

18,636

3,33%

18,568

2,95%

static

15,300

16,000

4,58%

15,308

0,05%

qdig

14,820

15,008

1,27%

14,828

0,05%

qdig2

14,824

15,012

1,27%

14,838

0,09%

To summarize the patch lead to approx. 5% slowdown and 3% memory
overhead for typical applications (as always, you mileage may vary
depending on your system's architecture and OS although my
guesstimate
is that you will see even worse results in a 64bit environment). We
also
tested SugarCRM to get another sanity for these results and we got
similar results.

I am not quite sure where this leaves us with this patch. On one
hand
I
think now the effort has been made it's a good thing to offer it as
part
of PHP. The downside is of course some performance degradation and
possible instabilities as this patch continues to stabilize (it took
about two releases for us to stabilize the Zend Memory Manager even
after in-depth testing due to edge cases in allocation patterns and
various extensions, etc...).I'd be surprised if our team has found
all
possible bugs.

Personally I think the decision should be either in or out. Adding
this
as a compile option is not a good idea as it would create binary
compatibility issues and would be a pain for the community. I think
my
inclination is to commit the patch, not have it #ifdef'ed but always
compiled but to have the garbage collection itself turned off by
default
(mainly for stability reasons. Note: the increased memory footprint
and
performance loss also exists with the collection itself turned off).
We
can turn it on when we're in dev for snapshots so that we iron out
bugs.
That said, as you can see from the results most people and real-life
applications will be worse off than today.

Thanks to David & Dmitry for working hard on this (and everyone else
who
contributed).

The stage is open for ideas/thoughts/suggestions J

Andi
Andi,

I don't know about how it worked for anyone else, but the tables
didn't display properly on Gmail, so I had a hard time keeping up with
the performance differences. If you have this in a separate file,
could you send it to me as an attachment? I have a few real-world
benchmarks I'd like to try from the angle of the shared-webhost
industry (lots of users with horrible code running simultaneously, et
cetera) which I'd like to compare to your notes.
Thanks.
--
Daniel P. Brown
[office] (570-) 587-7080 Ext. 272
[mobile] (570-) 766-8107

If at first you don't succeed, stick to what you know best so that you
can make enough money to pay someone else to do it for you.

--
Daniel P. Brown
[office] (570-) 587-7080 Ext. 272
[mobile] (570-) 766-8107

If at first you don't succeed, stick to what you know best so that you
can make enough money to pay someone else to do it for you.

17 years ago by Daniel Brown — view source

unread

Markus,

If for some reason the PDF attachment didn't come through to you

on the list, let me know and I'll upload it to one of my servers for
you to download and use, as well.

That looks great, Andi.

Thanks.
Sorry about that. Does the attached PDFed screenshot work for you?

Andi
-----Original Message-----
From: Daniel Brown [mailto:parasane@gmail.com]
Sent: Monday, December 03, 2007 1:21 PM
To: Andi Gutmans
Cc: internals@lists.php.net
Subject: Re: [PHP-DEV] Garbage collector patch
Hi all,

Was hoping to send this off earlier but I was travelling for the
past
week and had very limited email access.

As promised in the past few weeks we have spent a significant amount
of
time in reviewing the garbage collector work and testing it in our
performance lab. Dmitry has been exchanging ideas and patches with
David
Wang during this time. Suffice to say that as I've mentioned in the
past, memory management is an extremely sensitive piece of PHP,
which
is
why it was important for us to review this work in great depth
before
committing it to the code base.

The updated patch still retains the same algorithm as David's
original
implementation however the data structures have been changed in
order
to
work faster and use less memory.

The revised patch has the following advantages:

It fixes several crash bugs

Enhances performance by removing several unnecessary checks

The memory overhead was reduced (from 12 to 4 bytes for each
heap-allocated zval)

The speed of "clean" PHP code (code that doesn't create cycles)
was
improved

Additional test cases were created

The end result is a more stable and faster GC patch. That said we
have
yet to find real-life applications that create significant cycles
which
would benefit from this patch. In fact as you'll see from the
results
our tests show an increase in maximum memory use and slower
execution
(to be fair they are marginal).

We have tested both PHP_5_3 without any patches, the original patch
and
the new patch.

The following table shows execution time (seconds for N requests)
and
slowdown.
    PHP_5_3
Original GC patch

Current GC patch

slowdown

slowdown

bench

11,550

12,310

6,58%

12,170

5,37%

hello

8,781

8,852

0,81%

8,813

0,36%

xoops

128,500

135,100

5,14%

130,200

1,32%

static

18,540

20,840

12,41%

18,920

2,05%

qdig

29,320

30,270

3,24%

29,610

0,99%

qdig2

13,960

14,100

1,00%

14,090

0,93%

The next table shows memory usage in MB and overhead
    PHP_5_3
Original GC patch

Current GC patch

overhead

overhead

hello

13,750

13,945

1,42%

13,765

0,11%

xoops

18,036

18,636

3,33%

18,568

2,95%

static

15,300

16,000

4,58%

15,308

0,05%

qdig

14,820

15,008

1,27%

14,828

0,05%

qdig2

14,824

15,012

1,27%

14,838

0,09%

To summarize the patch lead to approx. 5% slowdown and 3% memory
overhead for typical applications (as always, you mileage may vary
depending on your system's architecture and OS although my
guesstimate
is that you will see even worse results in a 64bit environment). We
also
tested SugarCRM to get another sanity for these results and we got
similar results.

I am not quite sure where this leaves us with this patch. On one
hand
I
think now the effort has been made it's a good thing to offer it as
part
of PHP. The downside is of course some performance degradation and
possible instabilities as this patch continues to stabilize (it took
about two releases for us to stabilize the Zend Memory Manager even
after in-depth testing due to edge cases in allocation patterns and
various extensions, etc...).I'd be surprised if our team has found
all
possible bugs.

Personally I think the decision should be either in or out. Adding
this
as a compile option is not a good idea as it would create binary
compatibility issues and would be a pain for the community. I think
my
inclination is to commit the patch, not have it #ifdef'ed but always
compiled but to have the garbage collection itself turned off by
default
(mainly for stability reasons. Note: the increased memory footprint
and
performance loss also exists with the collection itself turned off).
We
can turn it on when we're in dev for snapshots so that we iron out
bugs.
That said, as you can see from the results most people and real-life
applications will be worse off than today.

Thanks to David & Dmitry for working hard on this (and everyone else
who
contributed).

The stage is open for ideas/thoughts/suggestions J

Andi
Andi,

I don't know about how it worked for anyone else, but the tables
didn't display properly on Gmail, so I had a hard time keeping up with
the performance differences. If you have this in a separate file,
could you send it to me as an attachment? I have a few real-world
benchmarks I'd like to try from the angle of the shared-webhost
industry (lots of users with horrible code running simultaneously, et
cetera) which I'd like to compare to your notes.
Thanks.
--
Daniel P. Brown
[office] (570-) 587-7080 Ext. 272
[mobile] (570-) 766-8107

If at first you don't succeed, stick to what you know best so that you
can make enough money to pay someone else to do it for you.
--

Daniel P. Brown
[office] (570-) 587-7080 Ext. 272
[mobile] (570-) 766-8107

If at first you don't succeed, stick to what you know best so that you
can make enough money to pay someone else to do it for you.

--
Daniel P. Brown
[office] (570-) 587-7080 Ext. 272
[mobile] (570-) 766-8107

If at first you don't succeed, stick to what you know best so that you
can make enough money to pay someone else to do it for you.

17 years ago by Edward Z. Yang — view source

unread

Daniel Brown wrote:

If for some reason the PDF attachment didn't come through to you
on the list, let me know and I'll upload it to one of my servers for
you to download and use, as well.

The PDF didn't make it through for me. Can you upload it?

--
Edward Z. Yang GnuPG: 0x869C48DA
HTML Purifier http://htmlpurifier.org Anti-XSS Filter
[[ 3FA8 E9A9 7385 B691 A6FC B3CB A933 BE7D 869C 48DA ]]

17 years ago by Andi Gutmans — view source

unread

Argh. Here you go: http://cvs.php.net/~andi/GC_email.pdf

-----Original Message-----
From: Edward Z. Yang [mailto:edwardzyang@thewritingpot.com]
Sent: Monday, December 03, 2007 1:43 PM
To: internals@lists.php.net
Subject: Re: [PHP-DEV] Garbage collector patch

Daniel Brown wrote:

If for some reason the PDF attachment didn't come through to you
on the list, let me know and I'll upload it to one of my servers for
you to download and use, as well.

The PDF didn't make it through for me. Can you upload it?

--
Edward Z. Yang GnuPG: 0x869C48DA
HTML Purifier http://htmlpurifier.org Anti-XSS Filter
[[ 3FA8 E9A9 7385 B691 A6FC B3CB A933 BE7D 869C 48DA ]]

17 years ago by Markus Fischer — view source

unread

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

Hi,

yes exactly, there was no PDF attachment. Interestingly the signature
was a separate attachment ...

thanks

- Markus

Daniel Brown wrote:

Markus,

If for some reason the PDF attachment didn't come through to you
on the list, let me know and I'll upload it to one of my servers for
you to download and use, as well.
That looks great, Andi.

Thanks.
Sorry about that. Does the attached PDFed screenshot work for you?

Andi
-----Original Message-----
From: Daniel Brown [mailto:parasane@gmail.com]
Sent: Monday, December 03, 2007 1:21 PM
To: Andi Gutmans
Cc: internals@lists.php.net
Subject: Re: [PHP-DEV] Garbage collector patch
Hi all,

Was hoping to send this off earlier but I was travelling for the
past
week and had very limited email access.

As promised in the past few weeks we have spent a significant amount
of
time in reviewing the garbage collector work and testing it in our
performance lab. Dmitry has been exchanging ideas and patches with
David
Wang during this time. Suffice to say that as I've mentioned in the
past, memory management is an extremely sensitive piece of PHP,
which
is
why it was important for us to review this work in great depth
before
committing it to the code base.

The updated patch still retains the same algorithm as David's
original
implementation however the data structures have been changed in
order
to
work faster and use less memory.

The revised patch has the following advantages:

It fixes several crash bugs

Enhances performance by removing several unnecessary checks

The memory overhead was reduced (from 12 to 4 bytes for each
heap-allocated zval)

The speed of "clean" PHP code (code that doesn't create cycles)
was
improved

Additional test cases were created

The end result is a more stable and faster GC patch. That said we
have
yet to find real-life applications that create significant cycles
which
would benefit from this patch. In fact as you'll see from the
results
our tests show an increase in maximum memory use and slower
execution
(to be fair they are marginal).

We have tested both PHP_5_3 without any patches, the original patch
and
the new patch.

The following table shows execution time (seconds for N requests)
and
slowdown.
    PHP_5_3
Original GC patch

Current GC patch

slowdown

slowdown

bench

11,550

12,310

6,58%

12,170

5,37%

hello

8,781

8,852

0,81%

8,813

0,36%

xoops

128,500

135,100

5,14%

130,200

1,32%

static

18,540

20,840

12,41%

18,920

2,05%

qdig

29,320

30,270

3,24%

29,610

0,99%

qdig2

13,960

14,100

1,00%

14,090

0,93%

The next table shows memory usage in MB and overhead
    PHP_5_3
Original GC patch

Current GC patch

overhead

overhead

hello

13,750

13,945

1,42%

13,765

0,11%

xoops

18,036

18,636

3,33%

18,568

2,95%

static

15,300

16,000

4,58%

15,308

0,05%

qdig

14,820

15,008

1,27%

14,828

0,05%

qdig2

14,824

15,012

1,27%

14,838

0,09%

To summarize the patch lead to approx. 5% slowdown and 3% memory
overhead for typical applications (as always, you mileage may vary
depending on your system's architecture and OS although my
guesstimate
is that you will see even worse results in a 64bit environment). We
also
tested SugarCRM to get another sanity for these results and we got
similar results.

I am not quite sure where this leaves us with this patch. On one
hand
I
think now the effort has been made it's a good thing to offer it as
part
of PHP. The downside is of course some performance degradation and
possible instabilities as this patch continues to stabilize (it took
about two releases for us to stabilize the Zend Memory Manager even
after in-depth testing due to edge cases in allocation patterns and
various extensions, etc...).I'd be surprised if our team has found
all
possible bugs.

Personally I think the decision should be either in or out. Adding
this
as a compile option is not a good idea as it would create binary
compatibility issues and would be a pain for the community. I think
my
inclination is to commit the patch, not have it #ifdef'ed but always
compiled but to have the garbage collection itself turned off by
default
(mainly for stability reasons. Note: the increased memory footprint
and
performance loss also exists with the collection itself turned off).
We
can turn it on when we're in dev for snapshots so that we iron out
bugs.
That said, as you can see from the results most people and real-life
applications will be worse off than today.

Thanks to David & Dmitry for working hard on this (and everyone else
who
contributed).

The stage is open for ideas/thoughts/suggestions J

Andi
Andi,

I don't know about how it worked for anyone else, but the tables
didn't display properly on Gmail, so I had a hard time keeping up with
the performance differences. If you have this in a separate file,
could you send it to me as an attachment? I have a few real-world
benchmarks I'd like to try from the angle of the shared-webhost
industry (lots of users with horrible code running simultaneously, et
cetera) which I'd like to compare to your notes.
Thanks.
--
Daniel P. Brown
[office] (570-) 587-7080 Ext. 272
[mobile] (570-) 766-8107

If at first you don't succeed, stick to what you know best so that you
can make enough money to pay someone else to do it for you.
--

Daniel P. Brown
[office] (570-) 587-7080 Ext. 272
[mobile] (570-) 766-8107

If at first you don't succeed, stick to what you know best so that you
can make enough money to pay someone else to do it for you.

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Version: GnuPG v1.4.6 (MingW32)
Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org

iD8DBQFHVHi/1nS0RcInK9ARAp4KAKDKG2s1T4JZgPlAQJpsQsj7iVoSqACfQ9qt
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17 years ago by Sean Coates — view source

unread

Sorry about that. Does the attached PDFed screenshot work for you?

If only we knew how to publish documents on that 'web thing.........

(-:

S

17 years ago by Derick Rethans — view source

unread

Sorry about that. Does the attached PDFed screenshot work for you?

No, as you can't attach files here....

Derick

--
Derick Rethans
http://derickrethans.nl | http://ez.no | http://xdebug.org

17 years ago by Daniel Brown — view source

unread

Sorry about that. Does the attached PDFed screenshot work for you?

No, as you can't attach files here....

Derick

--
Derick Rethans
http://derickrethans.nl | http://ez.no | http://xdebug.org

I didn't think it would work on the list, but I figured if Andi

either sent it to me, or clicked Reply-All, either way it would be
delivered directly to my inbox, which it was. So now it's here:
http://www.pilotpig.net/pdfs/

--
Daniel P. Brown
[office] (570-) 587-7080 Ext. 272
[mobile] (570-) 766-8107

If at first you don't succeed, stick to what you know best so that you
can make enough money to pay someone else to do it for you.

17 years ago by Ilia Alshanetsky — view source

unread

First of all big thanks for Dmitry and David for spending time on this
project and continuing to improve the original patch. Based on the
results so far, I think the patch does have a value, but certainly not
in a general case. Relative simple scripts have little to gain from it
and only to loose 3-5% of speed depending on a situation and given
insubstantial memory gains it seems of little use in general case.
That said, there are complex applications (perhaps unnecessarily
so ;-) ) that could see some real benefits from this code. My
suggestion is that we make this feature a compile time flag, that's
off by default and people who feel that their applications warrant a
garbage collector can enable it for their install and at the same time
those who don't (general case) have no penalties of having it in place.

Hi all,

Was hoping to send this off earlier but I was travelling for the past
week and had very limited email access.

As promised in the past few weeks we have spent a significant amount
of
time in reviewing the garbage collector work and testing it in our
performance lab. Dmitry has been exchanging ideas and patches with
David
Wang during this time. Suffice to say that as I've mentioned in the
past, memory management is an extremely sensitive piece of PHP,
which is
why it was important for us to review this work in great depth before
committing it to the code base.

The updated patch still retains the same algorithm as David's original
implementation however the data structures have been changed in
order to
work faster and use less memory.

The revised patch has the following advantages:

It fixes several crash bugs

Enhances performance by removing several unnecessary checks

The memory overhead was reduced (from 12 to 4 bytes for each
heap-allocated zval)

The speed of "clean" PHP code (code that doesn't create cycles) was
improved

Additional test cases were created

The end result is a more stable and faster GC patch. That said we have
yet to find real-life applications that create significant cycles
which
would benefit from this patch. In fact as you'll see from the results
our tests show an increase in maximum memory use and slower execution
(to be fair they are marginal).

We have tested both PHP_5_3 without any patches, the original patch
and
the new patch.

The following table shows execution time (seconds for N requests) and
slowdown.

PHP_5_3

Original GC patch

Current GC patch

slowdown

slowdown

bench

11,550

12,310

6,58%

12,170

5,37%

hello

8,781

8,852

0,81%

8,813

0,36%

xoops

128,500

135,100

5,14%

130,200

1,32%

static

18,540

20,840

12,41%

18,920

2,05%

qdig

29,320

30,270

3,24%

29,610

0,99%

qdig2

13,960

14,100

1,00%

14,090

0,93%

The next table shows memory usage in MB and overhead

PHP_5_3

Original GC patch

Current GC patch

overhead

overhead

hello

13,750

13,945

1,42%

13,765

0,11%

xoops

18,036

18,636

3,33%

18,568

2,95%

static

15,300

16,000

4,58%

15,308

0,05%

qdig

14,820

15,008

1,27%

14,828

0,05%

qdig2

14,824

15,012

1,27%

14,838

0,09%

To summarize the patch lead to approx. 5% slowdown and 3% memory
overhead for typical applications (as always, you mileage may vary
depending on your system's architecture and OS although my guesstimate
is that you will see even worse results in a 64bit environment). We
also
tested SugarCRM to get another sanity for these results and we got
similar results.

I am not quite sure where this leaves us with this patch. On one
hand I
think now the effort has been made it's a good thing to offer it as
part
of PHP. The downside is of course some performance degradation and
possible instabilities as this patch continues to stabilize (it took
about two releases for us to stabilize the Zend Memory Manager even
after in-depth testing due to edge cases in allocation patterns and
various extensions, etc...).I'd be surprised if our team has found all
possible bugs.

Personally I think the decision should be either in or out. Adding
this
as a compile option is not a good idea as it would create binary
compatibility issues and would be a pain for the community. I think my
inclination is to commit the patch, not have it #ifdef'ed but always
compiled but to have the garbage collection itself turned off by
default
(mainly for stability reasons. Note: the increased memory footprint
and
performance loss also exists with the collection itself turned off).
We
can turn it on when we're in dev for snapshots so that we iron out
bugs.
That said, as you can see from the results most people and real-life
applications will be worse off than today.

Thanks to David & Dmitry for working hard on this (and everyone else
who
contributed).

The stage is open for ideas/thoughts/suggestions J

Andi

Ilia Alshanetsky

17 years ago by Cristian Rodriguez — view source

unread

2007/12/3, Ilia Alshanetsky ilia@prohost.org:

I think the patch does have a value,

yes, it does, what worries me is the introduction of yet another
non-sense ini setting that modified the very engine behaviuor.. I
think we all agree that there are way too many of those do we ?

. My

suggestion is that we make this feature a compile time flag.

My suggestion is not to add any compile time flag, either provide it or dont.

and people who feel that their applications warrant a
garbage collector can enable it for their install and at the same time
those who don't (general case) have no penalties of having it in place.

People more commonly uses PHP from distributors, in binary form.. they
dont usually decide what is enabled or not, so you have to either
reccommend this feature or mark it clearly as untrusted, experimental.

such switches only add more complexity, confusion for users and
addtional trouble to distributors.

my 2CLP.

--
http://www.kissofjudas.net/

17 years ago by Steph Fox — view source

unread

such switches only add more complexity, confusion for users and
addtional trouble to distributors.

FWIW, amen to that.

Steph

17 years ago by Antony Dovgal — view source

unread

such switches only add more complexity, confusion for users and
addtional trouble to distributors.

... which I believe are going to enable this flag by default anyway,
because they don't care about performance too much.

So I agree, either do it or not, yet another engine mode is bad idea.

--
Wbr,
Antony Dovgal

17 years ago by Alexey Zakhlestin — view source

unread

I believe this has to be done and it should be always on.
Having less headache is good. I will find other ways to speed up my projects

such switches only add more complexity, confusion for users and
addtional trouble to distributors.

... which I believe are going to enable this flag by default anyway,
because they don't care about performance too much.

So I agree, either do it or not, yet another engine mode is bad idea.

--
Wbr,
Antony Dovgal

--

--
Alexey Zakhlestin
http://blog.milkfarmsoft.com/

17 years ago by Andi Gutmans — view source

unread

You may be right longer term but shorter term I still believe there may be stability issues with this patch some of which we haven't figured out. Although we did testing and found crash bugs I wouldn't trust our level of testing to deem it stable. If we go down the route of always on we could have a hidden ini file (not listed in php.ini-dist and phpinfo()) which we can advise to turn off if something goes wrong and once we can enough confidence that there aren't any lurking bugs we could remove it.

Andi

-----Original Message-----
From: Antony Dovgal [mailto:tony@daylessday.org]
Sent: Tuesday, December 04, 2007 12:28 AM
To: Cristian Rodriguez
Cc: internals@lists.php.net
Subject: Re: [PHP-DEV] Garbage collector patch

such switches only add more complexity, confusion for users and
addtional trouble to distributors.

... which I believe are going to enable this flag by default anyway,
because they don't care about performance too much.

So I agree, either do it or not, yet another engine mode is bad idea.

--
Wbr,
Antony Dovgal

17 years ago by Antony Dovgal — view source

unread

You may be right longer term but shorter term I still believe there may be stability issues with this patch some of which we haven't figured out. Although we did testing and found crash bugs I wouldn't trust our level of testing to deem it stable. If we go down the route of always on we could have a hidden ini file (not listed in php.ini-dist and phpinfo()) which we can advise to turn off if something goes wrong and once we can enough confidence that there aren't any lurking bugs we could remove it.

You mean provide an ini setting to be able to turn it Off?
But why do you call it "always On" then?
And what's the difference comparing to what you've proposed earlier?

Concerning the stability issues, I'd say we have quite good chance
to make it stable enough, as (I hope) 5.3.0 is not going to be released
for at least several months more.

Companies that are especially concerned of performance/stability
are encouraged to step forward and give us a hand.

--
Wbr,
Antony Dovgal

17 years ago by Rasmus Lerdorf — view source

unread

Antony Dovgal wrote:

You may be right longer term but shorter term I still believe there may be stability issues with this patch some of which we haven't figured out. Although we did testing and found crash bugs I wouldn't trust our level of testing to deem it stable. If we go down the route of always on we could have a hidden ini file (not listed in php.ini-dist and phpinfo()) which we can advise to turn off if something goes wrong and once we can enough confidence that there aren't any lurking bugs we could remove it.

You mean provide an ini setting to be able to turn it Off?
But why do you call it "always On" then?
And what's the difference comparing to what you've proposed earlier?

Concerning the stability issues, I'd say we have quite good chance
to make it stable enough, as (I hope) 5.3.0 is not going to be released
for at least several months more.

Companies that are especially concerned of performance/stability
are encouraged to step forward and give us a hand.

Companies concerned about performance aren't going to use it at all. A
5% hit is significant given that it doesn't fix anything that a company
already concerned about performance/stability cares about. Super leaky
or recursively allocating scripts have long since been weeded out of
those code bases, so it is a 5% performance hit with no gain.

I am not arguing that it isn't useful in the general case. It will make
PHP more robust on loosely controlled servers for what amounts to only a
small penalty, but at the same time it is an easy 5% win for people with
dedicated servers running well-written code.

-Rasmus

17 years ago by scott.mcnaught@synergy8.com — view source

unread

I think having it configurable is a must. Turning it on / off via a compile flag will not suit everyone.

Eg - I have a situation where I would not want to run garbage collection for web pages served off my server due to the performance hit, however I also have a CLI script which I run to do complex, but repetitive tasks for ~half an hour.

Now this is not really a big deal to me as I managed to rid most of the leaks by nulling out cyclic references, however that took a lot of work which could have been avoided by this.

Could I suggest also enabling it by default for CLI?

SCOTT MCNAUGHT
Software Developer

Synergy 8 / +617 3397 5212
scott.mcnaught@synergy8.com

-----Original Message-----
From: Rasmus Lerdorf [mailto:rasmus@lerdorf.com]
Sent: Wednesday, 5 December 2007 5:17 AM
To: Antony Dovgal
Cc: Andi Gutmans; Cristian Rodriguez; internals@lists.php.net
Subject: Re: [PHP-DEV] Garbage collector patch

Antony Dovgal wrote:

You may be right longer term but shorter term I still believe there may be stability issues with this patch some of which we haven't figured out. Although we did testing and found crash bugs I wouldn't trust our level of testing to deem it stable. If we go down the route of always on we could have a hidden ini file (not listed in php.ini-dist and phpinfo()) which we can advise to turn off if something goes wrong and once we can enough confidence that there aren't any lurking bugs we could remove it.

You mean provide an ini setting to be able to turn it Off?
But why do you call it "always On" then?
And what's the difference comparing to what you've proposed earlier?

Concerning the stability issues, I'd say we have quite good chance
to make it stable enough, as (I hope) 5.3.0 is not going to be released
for at least several months more.

Companies that are especially concerned of performance/stability
are encouraged to step forward and give us a hand.

Companies concerned about performance aren't going to use it at all. A
5% hit is significant given that it doesn't fix anything that a company
already concerned about performance/stability cares about. Super leaky
or recursively allocating scripts have long since been weeded out of
those code bases, so it is a 5% performance hit with no gain.

I am not arguing that it isn't useful in the general case. It will make
PHP more robust on loosely controlled servers for what amounts to only a
small penalty, but at the same time it is an easy 5% win for people with
dedicated servers running well-written code.

-Rasmus

17 years ago by Rasmus Lerdorf — view source

unread

scott.mcnaught@synergy8.com wrote:

I think having it configurable is a must. Turning it on / off via a compile flag will not suit everyone.

Looking at the code, that isn't really possible. You could have a
switch to turn off the collection, but that won't get you your
performance back. To avoid the performance penalty you need it to be a
compile-time decision.

I only see 2 possible workable solutions here:

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.
Drop it

-Rasmus

17 years ago by Stanislav Malyshev — view source

unread

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.

Stanislav Malyshev, Zend Software Architect
stas@zend.com http://www.zend.com/
(408)253-8829 MSN: stas@zend.com

17 years ago by Rasmus Lerdorf — view source

unread

Stanislav Malyshev wrote:

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.

-Rasmus

17 years ago by Richard Lynch — view source

unread

Stanislav Malyshev wrote:

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?

17 years ago by Ilia Alshanetsky — view source

unread

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.

Stanislav Malyshev wrote:

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?

--

Ilia Alshanetsky

17 years ago by Andi Gutmans — view source

unread

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.

Stanislav Malyshev wrote:

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?

--

Ilia Alshanetsky

17 years ago by Nathan Rixham — view source

unread

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.

Stanislav Malyshev wrote:

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?

--

Ilia Alshanetsky

17 years ago by Sam Barrow — view source

unread

A few weeks ago I wrote a message on this list about my patch for scalar
type hinting. I've been using it for about a month now in a large scale
application im developing with no problems. It allows type hinting for
the following types: int, float, string, bool (boolean), num (int or
float), scalar (int, float, string, or bool), object, and resource.

All of these types have been very useful. Num has been useful for any
mathematical functions, scalar has been the most useful, mostly for
echoing values and interacting with the database (as a database cant
store arrays or objects).

The type hinting is all 100% optional and has caused no problems for me
at all, I use it in most function but some functions I'll use it for one
parameter and not the other, or none at all with no problems.

What is the general opinion on this? Examples below:

<?php

function multiply(num $a, num b) {
return $a * $b ;
}

multiply(5, 1) ; // works

multiply(3.7, 8.2) // works

multiply("foo", 5) ; // Catchable fatal error: Argument 1 passed to
multiply() must be a number, string given

function displayStuff(scalar $stuff) {
echo $stuff ;
}

displayStuff('Hello!') ; // works

displayStuff(123) ; // works

displayStuff(array('a' => 'b')) ; // Catchable fatal error: Argument 1
passed to displayStuff() must be a scalar, array given

?

17 years ago by christian.mueller@dfpx.de — view source

unread

Sam Barrow schrieb:

What is the general opinion on this?

I am all for it.

And i think you (or someone else) had it combined with overloading, wich
would be a quite nice extra benefit.

--
Chris

17 years ago by christian.mueller@dfpx.de — view source

unread

Sam Barrow schrieb:

What is the general opinion on this?

I'm all for it.
Would be using it already, if it where available as an extension.

Do i recall right, that you (or someone else) had this combined with
overloading?

--
Chris

17 years ago by Sam Barrow — view source

unread

I didn't do anything with overloading, just this.

Also, due to its functionality, it's not something that can be made into
an extension, it would have to go directly into the php source.

I have the patch if you want it, let me know. I've been using it for
almost a month now with PHP 5.3 with no problems.

Sam Barrow schrieb:

What is the general opinion on this?

I'm all for it.
Would be using it already, if it where available as an extension.

Do i recall right, that you (or someone else) had this combined with
overloading?

--
Chris

17 years ago by Hannes Magnusson — view source

unread

Also, due to its functionality, it's not something that can be made into
an extension, it would have to go directly into the php source.

http://pecl.php.net/package/params
http://pecl.php.net/package/SPL_Types

Could you please show us the respect of doing a bit of a research on
the topic you are posting?
Be it type hinting, namespaces or whatever. It is getting very
annoying seeing you resurrect topics that have been declined million
times before.

If you keep this up you risk being ignored on whatever topic you may
bring up, even if its totally valid.

-Hannes

17 years ago by Sebastian Bergmann — view source

unread

Sam Barrow schrieb:

A few weeks ago I wrote a message on this list

Please do not start a new discussion by replying to a posting that
belongs to a previous thread. This, too, has been written on the list.

--
Sebastian Bergmann http://sebastian-bergmann.de/
GnuPG Key: 0xB85B5D69 / 27A7 2B14 09E4 98CD 6277 0E5B 6867 C514 B85B 5D69

17 years ago by Markus Fischer — view source

unread

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

For the record, I'm all for it. Optionality means flexibility. If one
doesn't want to use it, he doesn't have to.

Can you send a patch against 5.3 in CVS?

Have you thought about type hinting for return values?

thanks,

- Markus

Sam Barrow wrote:

A few weeks ago I wrote a message on this list about my patch for scalar
type hinting. I've been using it for about a month now in a large scale
application im developing with no problems. It allows type hinting for
the following types: int, float, string, bool (boolean), num (int or
float), scalar (int, float, string, or bool), object, and resource.

All of these types have been very useful. Num has been useful for any
mathematical functions, scalar has been the most useful, mostly for
echoing values and interacting with the database (as a database cant
store arrays or objects).

The type hinting is all 100% optional and has caused no problems for me
at all, I use it in most function but some functions I'll use it for one
parameter and not the other, or none at all with no problems.

What is the general opinion on this? Examples below:

<?php

function multiply(num $a, num b) {
return $a * $b ;
}

multiply(5, 1) ; // works

multiply(3.7, 8.2) // works

multiply("foo", 5) ; // Catchable fatal error: Argument 1 passed to
multiply() must be a number, string given

function displayStuff(scalar $stuff) {
echo $stuff ;
}

displayStuff('Hello!') ; // works

displayStuff(123) ; // works

displayStuff(array('a' => 'b')) ; // Catchable fatal error: Argument 1
passed to displayStuff() must be a scalar, array given

?>

-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.6 (MingW32)
Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org

iD8DBQFHXv8e1nS0RcInK9ARApVaAJ9vwTTVdH+HNENA64wfaPbkyCyG9gCgrMuy
CD2xQpN43p0dlgPIiYm2Ckg=
=ZOm7
-----END PGP SIGNATURE

17 years ago by Derick Rethans — view source

unread

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.

I am all for this.

regards,
Derick

--
Derick Rethans
http://derickrethans.nl | http://ezcomponents.org | http://xdebug.org

17 years ago by Jani Taskinen — view source

unread

2007/12/3, Ilia Alshanetsky ilia@prohost.org:

I think the patch does have a value,

yes, it does, what worries me is the introduction of yet another
non-sense ini setting that modified the very engine behaviuor.. I
think we all agree that there are way too many of those do we ?

Yup. :)

My
suggestion is that we make this feature a compile time flag.

My suggestion is not to add any compile time flag, either provide it or dont.

I have to agree. Either it's in or not. We've had enough trouble with
giving too much rope for people already..

--
Patches/Donations: http://pecl.php.net/~jani/

17 years ago by dz@bitxtender.com — view source

unread

I could be wrong, of course, but my guess is that the ~3% speed decrease
a) is not really significant to 95% of the users (I mean really
significant; of course, everyone is going to whine about it first) and
b) is going to be eliminated over time

david

Am 04.12.2007 um 03:43 schrieb Ilia Alshanetsky:

First of all big thanks for Dmitry and David for spending time on
this project and continuing to improve the original patch. Based on
the results so far, I think the patch does have a value, but
certainly not in a general case. Relative simple scripts have little
to gain from it and only to loose 3-5% of speed depending on a
situation and given insubstantial memory gains it seems of little
use in general case. That said, there are complex applications
(perhaps unnecessarily so ;-) ) that could see some real benefits
from this code. My suggestion is that we make this feature a compile
time flag, that's off by default and people who feel that their
applications warrant a garbage collector can enable it for their
install and at the same time those who don't (general case) have no
penalties of having it in place.

Hi all,

Was hoping to send this off earlier but I was travelling for the past
week and had very limited email access.

As promised in the past few weeks we have spent a significant
amount of
time in reviewing the garbage collector work and testing it in our
performance lab. Dmitry has been exchanging ideas and patches with
David
Wang during this time. Suffice to say that as I've mentioned in the
past, memory management is an extremely sensitive piece of PHP,
which is
why it was important for us to review this work in great depth before
committing it to the code base.

The updated patch still retains the same algorithm as David's
original
implementation however the data structures have been changed in
order to
work faster and use less memory.

The revised patch has the following advantages:

It fixes several crash bugs

Enhances performance by removing several unnecessary checks

The memory overhead was reduced (from 12 to 4 bytes for each
heap-allocated zval)

The speed of "clean" PHP code (code that doesn't create cycles) was
improved

Additional test cases were created

The end result is a more stable and faster GC patch. That said we
have
yet to find real-life applications that create significant cycles
which
would benefit from this patch. In fact as you'll see from the results
our tests show an increase in maximum memory use and slower execution
(to be fair they are marginal).

We have tested both PHP_5_3 without any patches, the original patch
and
the new patch.

The following table shows execution time (seconds for N requests) and
slowdown.

PHP_5_3

Original GC patch

Current GC patch

slowdown

slowdown

bench

11,550

12,310

6,58%

12,170

5,37%

hello

8,781

8,852

0,81%

8,813

0,36%

xoops

128,500

135,100

5,14%

130,200

1,32%

static

18,540

20,840

12,41%

18,920

2,05%

qdig

29,320

30,270

3,24%

29,610

0,99%

qdig2

13,960

14,100

1,00%

14,090

0,93%

The next table shows memory usage in MB and overhead

PHP_5_3

Original GC patch

Current GC patch

overhead

overhead

hello

13,750

13,945

1,42%

13,765

0,11%

xoops

18,036

18,636

3,33%

18,568

2,95%

static

15,300

16,000

4,58%

15,308

0,05%

qdig

14,820

15,008

1,27%

14,828

0,05%

qdig2

14,824

15,012

1,27%

14,838

0,09%

To summarize the patch lead to approx. 5% slowdown and 3% memory
overhead for typical applications (as always, you mileage may vary
depending on your system's architecture and OS although my
guesstimate
is that you will see even worse results in a 64bit environment). We
also
tested SugarCRM to get another sanity for these results and we got
similar results.

I am not quite sure where this leaves us with this patch. On one
hand I
think now the effort has been made it's a good thing to offer it as
part
of PHP. The downside is of course some performance degradation and
possible instabilities as this patch continues to stabilize (it took
about two releases for us to stabilize the Zend Memory Manager even
after in-depth testing due to edge cases in allocation patterns and
various extensions, etc...).I'd be surprised if our team has found
all
possible bugs.

Personally I think the decision should be either in or out. Adding
this
as a compile option is not a good idea as it would create binary
compatibility issues and would be a pain for the community. I think
my
inclination is to commit the patch, not have it #ifdef'ed but always
compiled but to have the garbage collection itself turned off by
default
(mainly for stability reasons. Note: the increased memory footprint
and
performance loss also exists with the collection itself turned
off). We
can turn it on when we're in dev for snapshots so that we iron out
bugs.
That said, as you can see from the results most people and real-life
applications will be worse off than today.

Thanks to David & Dmitry for working hard on this (and everyone
else who
contributed).

The stage is open for ideas/thoughts/suggestions J

Andi

Ilia Alshanetsky

--

--
David Zülke
dz@bitxtender.com
Tel: +49 (0)89 57 08 15 15
bitXtender GbR
Paul-Heyse-Straße 6
80336 München

17 years ago by Stanislav Malyshev — view source

unread

I could be wrong, of course, but my guess is that the ~3% speed decrease
a) is not really significant to 95% of the users (I mean really
significant; of course, everyone is going to whine about it first) and

GC is not really useful to 95% of the users either, so is 5% of the
users important or not?

b) is going to be eliminated over time

What is going to be eliminated, the slowdown? How?

Stanislav Malyshev, Zend Software Architect
stas@zend.com http://www.zend.com/
(408)253-8829 MSN: stas@zend.com

17 years ago by Stanislav Malyshev — view source

unread

that could see some real benefits from this code. My suggestion is that
we make this feature a compile time flag, that's off by default and

What about binary compatibility?

--
Stanislav Malyshev, Zend Software Architect
stas@zend.com http://www.zend.com/
(408)253-8829 MSN: stas@zend.com

17 years ago by Ronald Chmara — view source

unread

Hi all,

Was hoping to send this off earlier but I was travelling for the past
week and had very limited email access.

As promised in the past few weeks we have spent a significant
amount of
time in reviewing the garbage collector work and testing it in our
performance lab. Dmitry has been exchanging ideas and patches with
David
Wang during this time. Suffice to say that as I've mentioned in the
past, memory management is an extremely sensitive piece of PHP,
which is
why it was important for us to review this work in great depth before
committing it to the code base.

The updated patch still retains the same algorithm as David's original
implementation however the data structures have been changed in
order to
work faster and use less memory.
...
Personally I think the decision should be either in or out. Adding
this
as a compile option is not a good idea as it would create binary
compatibility issues and would be a pain for the community.
...
The stage is open for ideas/thoughts/suggestions

I'm really hesitant to even mention this idea, but....

Could "alternate" memory management systems be made available via
PECL add-ons, or, more to the point:
What is the actual cost and complexity involved in implementing
(possibly many) different user-selectable memory management systems,
and what other future benefits/drawbacks might we see by doing such a
thing? (GC is big now, but what about memory pools per mod_auth user,
or SHM/SEM pools, or tuning amounts of memory per function, etc...)

I will now apologize to everybody who I just made cry, scream, or
damage their furniture, as I didn't mean to hurt you, just trying to
stimulate ideas.

-Ronabop

17 years ago by Andi Gutmans — view source

unread

-----Original Message-----
From: Ronald Chmara [mailto:ron@Opus1.COM]
Sent: Monday, December 03, 2007 10:06 PM
To: Andi Gutmans
Cc: internals@lists.php.net
Subject: Re: [PHP-DEV] Garbage collector patch
I'm really hesitant to even mention this idea, but....

Could "alternate" memory management systems be made available via
PECL add-ons, or, more to the point:
What is the actual cost and complexity involved in implementing
(possibly many) different user-selectable memory management systems,
and what other future benefits/drawbacks might we see by doing such a
thing? (GC is big now, but what about memory pools per mod_auth user,
or SHM/SEM pools, or tuning amounts of memory per function, etc...)

I will now apologize to everybody who I just made cry, scream, or
damage their furniture, as I didn't mean to hurt you, just trying to
stimulate ideas.

Hi Ronald,

PHP 5.2.x already supports the ability to hook in different "page"
managers. In PHP 5.3 you can also override the memory allocation
functions. However, this would not include garbage collection like
algorithms which actually require changes in the core PHP data type such
as zvals. In fact the garbage collection adds memory to the basic
datatypes which is why I suggested to either always make these changes,
or don't make them so that we retain binary compatibility across all
builds of PHP.
So overriding basic memory allocation functions, yes, ability to provide
various GC implementations, no.

Andi

17 years ago by Ronald Chmara — view source

unread

-----Original Message-----
From: Ronald Chmara [mailto:ron@Opus1.COM]
What is the actual cost and complexity involved in implementing
(possibly many) different user-selectable memory management systems,
and what other future benefits/drawbacks might we see by doing such a
thing? (GC is big now, but what about memory pools per mod_auth user,
or SHM/SEM pools, or tuning amounts of memory per function, etc...)

I will now apologize to everybody who I just made cry, scream, or
damage their furniture, as I didn't mean to hurt you, just trying to
stimulate ideas.

Hi Ronald,

PHP 5.2.x already supports the ability to hook in different "page"
managers. In PHP 5.3 you can also override the memory allocation
functions. However, this would not include garbage collection like
algorithms which actually require changes in the core PHP data type
such
as zvals. In fact the garbage collection adds memory to the basic
datatypes which is why I suggested to either always make these
changes,
or don't make them so that we retain binary compatibility across all
builds of PHP.
So overriding basic memory allocation functions, yes, ability to
provide
various GC implementations, no.

Okay, so, without this patch, I can allocate mem, and destroy it, on
a per page level, but not on a zval level, and the choice is:
a) zval (etc.) destruction with this patch, which has a 5% speed hit
at times (varies per test)
b) no patch, no change
c) something which hasn't been thought of yet?

I'd have to (sadly) ask that anything that slows down PHP by 5%, to
improve performance for programmers that, uhm, "leak" or otherwise
gobble RAM, that they, uhm, refactor their code as professional
programmers.

Thanks for clearing it up for me, Andi.

-Bop

17 years ago by Daniel Brown — view source

unread

I'd have to (sadly) ask that anything that slows down PHP by 5%, to
improve performance for programmers that, uhm, "leak" or otherwise
gobble RAM, that they, uhm, refactor their code as professional
programmers.

In the general scope, Ron, you're correct.  Where I think this

could really shine is on a shared hosting server, where you may have
dozens - even hundreds - of small, novice web sites, all "programmed
real good-like".

--
Daniel P. Brown
[office] (570-) 587-7080 Ext. 272
[mobile] (570-) 766-8107

If at first you don't succeed, stick to what you know best so that you
can make enough money to pay someone else to do it for you.

17 years ago by Derick Rethans — view source

unread

The revised patch has the following advantages:

It fixes several crash bugs

So far, my tests only see new crash bugs... :/

Program received signal SIGSEGV, Segmentation fault.
[Switching to Thread 0x2ba1140c6930 (LWP 21108)]
0x00000000008be4fe in zend_std_read_property (object=0x1d7f670, member=0x1e3a1e8, type=0) at /home/derick/dev/php/php-5.3dev-gc/Zend/zend_object_handlers.c:338
338 property_info = zend_get_property_info(zobj->ce, member, (zobj->ce->__get != NULL) TSRMLS_CC);
(gdb) bt
#0 0x00000000008be4fe in zend_std_read_property (object=0x1d7f670, member=0x1e3a1e8, type=0) at /home/derick/dev/php/php-5.3dev-gc/Zend/zend_object_handlers.c:338
#1 0x0000000000907fd2 in zend_fetch_property_address_read_helper_SPEC_UNUSED_CONST (type=0, execute_data=0x7fff9c73ffa0)
at /home/derick/dev/php/php-5.3dev-gc/Zend/zend_vm_execute.h:16282
#2 0x00000000009081ca in ZEND_FETCH_OBJ_R_SPEC_UNUSED_CONST_HANDLER (execute_data=0x7fff9c73ffa0) at /home/derick/dev/php/php-5.3dev-gc/Zend/zend_vm_execute.h:16304
#3 0x00000000008c4694 in execute (op_array=0x1e17c70) at /home/derick/dev/php/php-5.3dev-gc/Zend/zend_vm_execute.h:87
#4 0x00000000008c4dec in zend_do_fcall_common_helper_SPEC (execute_data=0x7fff9c740df0) at /home/derick/dev/php/php-5.3dev-gc/Zend/zend_vm_execute.h:221
#5 0x00000000008c5b0d in ZEND_DO_FCALL_BY_NAME_SPEC_HANDLER (execute_data=0x7fff9c740df0) at /home/derick/dev/php/php-5.3dev-gc/Zend/zend_vm_execute.h:309
#6 0x00000000008c4694 in execute (op_array=0x1dce4e0) at /home/derick/dev/php/php-5.3dev-gc/Zend/zend_vm_execute.h:87
#7 0x00000000008c4dec in zend_do_fcall_common_helper_SPEC (execute_data=0x7fff9c741450) at /home/derick/dev/php/php-5.3dev-gc/Zend/zend_vm_execute.h:221
#8 0x00000000008c5b0d in ZEND_DO_FCALL_BY_NAME_SPEC_HANDLER (execute_data=0x7fff9c741450) at /home/derick/dev/php/php-5.3dev-gc/Zend/zend_vm_execute.h:309
#9 0x00000000008c4694 in execute (op_array=0x1e17dc0) at /home/derick/dev/php/php-5.3dev-gc/Zend/zend_vm_execute.h:87
#10 0x00000000008c4dec in zend_do_fcall_common_helper_SPEC (execute_data=0x7fff9c741c80) at /home/derick/dev/php/php-5.3dev-gc/Zend/zend_vm_execute.h:221
#11 0x00000000008c5b0d in ZEND_DO_FCALL_BY_NAME_SPEC_HANDLER (execute_data=0x7fff9c741c80) at /home/derick/dev/php/php-5.3dev-gc/Zend/zend_vm_execute.h:309
#12 0x00000000008c4694 in execute (op_array=0x1de1a70) at /home/derick/dev/php/php-5.3dev-gc/Zend/zend_vm_execute.h:87
#13 0x00000000008c4dec in zend_do_fcall_common_helper_SPEC (execute_data=0x7fff9c743bb0) at /home/derick/dev/php/php-5.3dev-gc/Zend/zend_vm_execute.h:221
#14 0x00000000008c5b0d in ZEND_DO_FCALL_BY_NAME_SPEC_HANDLER (execute_data=0x7fff9c743bb0) at /home/derick/dev/php/php-5.3dev-gc/Zend/zend_vm_execute.h:309
#15 0x00000000008c4694 in execute (op_array=0x1d69390) at /home/derick/dev/php/php-5.3dev-gc/Zend/zend_vm_execute.h:87
#16 0x00000000008c4dec in zend_do_fcall_common_helper_SPEC (execute_data=0x7fff9c745550) at /home/derick/dev/php/php-5.3dev-gc/Zend/zend_vm_execute.h:221
#17 0x00000000008c5b0d in ZEND_DO_FCALL_BY_NAME_SPEC_HANDLER (execute_data=0x7fff9c745550) at /home/derick/dev/php/php-5.3dev-gc/Zend/zend_vm_execute.h:309
#18 0x00000000008c4694 in execute (op_array=0x1a20250) at /home/derick/dev/php/php-5.3dev-gc/Zend/zend_vm_execute.h:87
#19 0x00000000008c4dec in zend_do_fcall_common_helper_SPEC (execute_data=0x7fff9c7459b0) at /home/derick/dev/php/php-5.3dev-gc/Zend/zend_vm_execute.h:221
#20 0x00000000008c5b0d in ZEND_DO_FCALL_BY_NAME_SPEC_HANDLER (execute_data=0x7fff9c7459b0) at /home/derick/dev/php/php-5.3dev-gc/Zend/zend_vm_execute.h:309
#21 0x00000000008c4694 in execute (op_array=0x1a18ed0) at /home/derick/dev/php/php-5.3dev-gc/Zend/zend_vm_execute.h:87
#22 0x00000000008c4dec in zend_do_fcall_common_helper_SPEC (execute_data=0x7fff9c746340) at /home/derick/dev/php/php-5.3dev-gc/Zend/zend_vm_execute.h:221
#23 0x00000000008c5b0d in ZEND_DO_FCALL_BY_NAME_SPEC_HANDLER (execute_data=0x7fff9c746340) at /home/derick/dev/php/php-5.3dev-gc/Zend/zend_vm_execute.h:309
#24 0x00000000008c4694 in execute (op_array=0x1a38be0) at /home/derick/dev/php/php-5.3dev-gc/Zend/zend_vm_execute.h:87
#25 0x00000000008c4dec in zend_do_fcall_common_helper_SPEC (execute_data=0x7fff9c7472e0) at /home/derick/dev/php/php-5.3dev-gc/Zend/zend_vm_execute.h:221
#26 0x00000000008c5b0d in ZEND_DO_FCALL_BY_NAME_SPEC_HANDLER (execute_data=0x7fff9c7472e0) at /home/derick/dev/php/php-5.3dev-gc/Zend/zend_vm_execute.h:309
#27 0x00000000008c4694 in execute (op_array=0x11b5430) at /home/derick/dev/php/php-5.3dev-gc/Zend/zend_vm_execute.h:87
#28 0x00000000008c4dec in zend_do_fcall_common_helper_SPEC (execute_data=0x7fff9c7475d0) at /home/derick/dev/php/php-5.3dev-gc/Zend/zend_vm_execute.h:221
#29 0x00000000008c5b0d in ZEND_DO_FCALL_BY_NAME_SPEC_HANDLER (execute_data=0x7fff9c7475d0) at /home/derick/dev/php/php-5.3dev-gc/Zend/zend_vm_execute.h:309
#30 0x00000000008c4694 in execute (op_array=0x1a38a90) at /home/derick/dev/php/php-5.3dev-gc/Zend/zend_vm_execute.h:87
#31 0x00000000008c4dec in zend_do_fcall_common_helper_SPEC (execute_data=0x7fff9c747800) at /home/derick/dev/php/php-5.3dev-gc/Zend/zend_vm_execute.h:221
#32 0x00000000008c5b0d in ZEND_DO_FCALL_BY_NAME_SPEC_HANDLER (execute_data=0x7fff9c747800) at /home/derick/dev/php/php-5.3dev-gc/Zend/zend_vm_execute.h:309
#33 0x00000000008c4694 in execute (op_array=0x1a4f700) at /home/derick/dev/php/php-5.3dev-gc/Zend/zend_vm_execute.h:87
#34 0x00000000008c4dec in zend_do_fcall_common_helper_SPEC (execute_data=0x7fff9c748650) at /home/derick/dev/php/php-5.3dev-gc/Zend/zend_vm_execute.h:221
#35 0x00000000008c5b0d in ZEND_DO_FCALL_BY_NAME_SPEC_HANDLER (execute_data=0x7fff9c748650) at /home/derick/dev/php/php-5.3dev-gc/Zend/zend_vm_execute.h:309
#36 0x00000000008c4694 in execute (op_array=0x1a4f5b0) at /home/derick/dev/php/php-5.3dev-gc/Zend/zend_vm_execute.h:87
#37 0x00000000008c4dec in zend_do_fcall_common_helper_SPEC (execute_data=0x7fff9c7494a0) at /home/derick/dev/php/php-5.3dev-gc/Zend/zend_vm_execute.h:221
#38 0x00000000008c5b0d in ZEND_DO_FCALL_BY_NAME_SPEC_HANDLER (execute_data=0x7fff9c7494a0) at /home/derick/dev/php/php-5.3dev-gc/Zend/zend_vm_execute.h:309
#39 0x00000000008c4694 in execute (op_array=0x1804ab0) at /home/derick/dev/php/php-5.3dev-gc/Zend/zend_vm_execute.h:87
#40 0x00000000008c4dec in zend_do_fcall_common_helper_SPEC (execute_data=0x7fff9c74a2f0) at /home/derick/dev/php/php-5.3dev-gc/Zend/zend_vm_execute.h:221
#41 0x00000000008c5b0d in ZEND_DO_FCALL_BY_NAME_SPEC_HANDLER (execute_data=0x7fff9c74a2f0) at /home/derick/dev/php/php-5.3dev-gc/Zend/zend_vm_execute.h:309
#42 0x00000000008c4694 in execute (op_array=0x12a5b20) at /home/derick/dev/php/php-5.3dev-gc/Zend/zend_vm_execute.h:87
#43 0x00000000008c4dec in zend_do_fcall_common_helper_SPEC (execute_data=0x7fff9c74c7c0) at /home/derick/dev/php/php-5.3dev-gc/Zend/zend_vm_execute.h:221
#44 0x00000000008c5b0d in ZEND_DO_FCALL_BY_NAME_SPEC_HANDLER (execute_data=0x7fff9c74c7c0) at /home/derick/dev/php/php-5.3dev-gc/Zend/zend_vm_execute.h:309
#45 0x00000000008c4694 in execute (op_array=0x10e5c40) at /home/derick/dev/php/php-5.3dev-gc/Zend/zend_vm_execute.h:87
#46 0x00000000008c4dec in zend_do_fcall_common_helper_SPEC (execute_data=0x7fff9c74dcd0) at /home/derick/dev/php/php-5.3dev-gc/Zend/zend_vm_execute.h:221
#47 0x00000000008c5b0d in ZEND_DO_FCALL_BY_NAME_SPEC_HANDLER (execute_data=0x7fff9c74dcd0) at /home/derick/dev/php/php-5.3dev-gc/Zend/zend_vm_execute.h:309
#48 0x00000000008c4694 in execute (op_array=0x10f1520) at /home/derick/dev/php/php-5.3dev-gc/Zend/zend_vm_execute.h:87
#49 0x00000000008c4dec in zend_do_fcall_common_helper_SPEC (execute_data=0x7fff9c74e090) at /home/derick/dev/php/php-5.3dev-gc/Zend/zend_vm_execute.h:221
#50 0x00000000008c5b0d in ZEND_DO_FCALL_BY_NAME_SPEC_HANDLER (execute_data=0x7fff9c74e090) at /home/derick/dev/php/php-5.3dev-gc/Zend/zend_vm_execute.h:309
#51 0x00000000008c4694 in execute (op_array=0x10a5f10) at /home/derick/dev/php/php-5.3dev-gc/Zend/zend_vm_execute.h:87
#52 0x00000000008c4dec in zend_do_fcall_common_helper_SPEC (execute_data=0x7fff9c74e5b0) at /home/derick/dev/php/php-5.3dev-gc/Zend/zend_vm_execute.h:221
#53 0x00000000008c5b0d in ZEND_DO_FCALL_BY_NAME_SPEC_HANDLER (execute_data=0x7fff9c74e5b0) at /home/derick/dev/php/php-5.3dev-gc/Zend/zend_vm_execute.h:309
#54 0x00000000008c4694 in execute (op_array=0x10a5480) at /home/derick/dev/php/php-5.3dev-gc/Zend/zend_vm_execute.h:87
#55 0x00000000008979b6 in zend_execute_scripts (type=8, retval=0x0, file_count=3) at /home/derick/dev/php/php-5.3dev-gc/Zend/zend.c:1159
#56 0x0000000000837d68 in php_execute_script (primary_file=0x7fff9c750b90) at /home/derick/dev/php/php-5.3dev-gc/main/main.c:2011
#57 0x0000000000937234 in main (argc=3, argv=0x7fff9c750dc8) at /home/derick/dev/php/php-5.3dev-gc/sapi/cli/php_cli.c:1140

bt-full:
#0 0x00000000008be4fe in zend_std_read_property (object=0x1d7f670, member=0x1e3a1e8, type=0) at /home/derick/dev/php/php-5.3dev-gc/Zend/zend_object_handlers.c:338
zobj = (zend_object *) 0x547
tmp_member = (zval *) 0x0
retval = (zval **) 0x273caf0
rv = (zval *) 0x0
property_info = (zend_property_info *) 0x7fff9c73f5f0
silent = 0
#1 0x0000000000907fd2 in zend_fetch_property_address_read_helper_SPEC_UNUSED_CONST (type=0, execute_data=0x7fff9c73ffa0)
at /home/derick/dev/php/php-5.3dev-gc/Zend/zend_vm_execute.h:16282
offset = (zval *) 0x1e3a1e8
opline = (zend_op *) 0x1e3a198
container = (zval *) 0x1d7f670
retval = (zval **) 0x7fff9c73fb68
#2 0x00000000009081ca in ZEND_FETCH_OBJ_R_SPEC_UNUSED_CONST_HANDLER (execute_data=0x7fff9c73ffa0) at /home/derick/dev/php/php-5.3dev-gc/Zend/zend_vm_execute.h:16304
No locals.
#3 0x00000000008c4694 in execute (op_array=0x1e17c70) at /home/derick/dev/php/php-5.3dev-gc/Zend/zend_vm_execute.h:87
execute_data = {opline = 0x1e3a198, function_state = {function = 0x1e17c70}, fbc = 0x0, called_scope = 0x0, op_array = 0x1e17c70, object = 0x0,
Ts = 0x7fff9c73f660, CVs = 0x7fff9c73f640, original_in_execution = 1 '\001', use_heap = 0 '\0', symbol_table = 0x1e9bb90, prev_execute_data = 0x7fff9c740df0,
old_error_reporting = 0x0}
#4 0x00000000008c4dec in zend_do_fcall_common_helper_SPEC (execute_data=0x7fff9c740df0) at /home/derick/dev/php/php-5.3dev-gc/Zend/zend_vm_execute.h:221
original_return_value = (zval **) 0x7fff9c741060
opline = (zend_op *) 0x1e1b428
current_scope = (zend_class_entry *) 0x1dcd560
current_called_scope = (zend_class_entry *) 0x1dcd560
current_this = (zval *) 0x1d7f670
should_change_scope = 1 '\001'
ex_object = (zval *) 0x0
#5 0x00000000008c5b0d in ZEND_DO_FCALL_BY_NAME_SPEC_HANDLER (execute_data=0x7fff9c740df0) at /home/derick/dev/php/php-5.3dev-gc/Zend/zend_vm_execute.h:309
No locals.
#6 0x00000000008c4694 in execute (op_array=0x1dce4e0) at /home/derick/dev/php/php-5.3dev-gc/Zend/zend_vm_execute.h:87
execute_data = {opline = 0x1e1b428, function_state = {function = 0x1e17c70}, fbc = 0x0, called_scope = 0x0, op_array = 0x1dce4e0, object = 0x1d7f670,
Ts = 0x7fff9c740188, CVs = 0x7fff9c740140, original_in_execution = 1 '\001', use_heap = 0 '\0', symbol_table = 0x1e5fea0, prev_execute_data = 0x7fff9c741450,
old_error_reporting = 0x0}

To reproduce, run the Template tests of the eZ Components:

mkdir ezc

cd ezc

svn co http://svn.ez.no/svn/ezcomponents/trunk

svn co http://svn.ez.no/svn/ezcomponents/scripts

./scripts/setup-env.sh

php UnitTest/src/run-tests.php Template

regards,
Derick

--
Derick Rethans
http://derickrethans.nl | http://ezcomponents.org | http://xdebug.org

17 years ago by Matthias Pigulla — view source

unread

To summarize the patch lead to approx. 5% slowdown and 3% memory
overhead for typical applications (as always, you mileage may vary
depending on your system's architecture and OS although my guesstimate
is that you will see even worse results in a 64bit environment).

Does that slowdown result from housekeeping tasks alone that are a
prerequisite for GCing or does it include running the new algorithm?

Is it possible to always perform (unconditionally compile in) the
necessary housekeeping tasks but stick with the current GC, so that
cycle-detection only happens when the user calls a gc_go_find_cycles()
function? Would that significantly improve the above numbers?

-mp.

17 years ago by Derick Rethans — view source

unread

To summarize the patch lead to approx. 5% slowdown and 3% memory
overhead for typical applications (as always, you mileage may vary
depending on your system's architecture and OS although my guesstimate
is that you will see even worse results in a 64bit environment).

Does that slowdown result from housekeeping tasks alone that are a
prerequisite for GCing or does it include running the new algorithm?

Is it possible to always perform (unconditionally compile in) the
necessary housekeeping tasks but stick with the current GC, so that
cycle-detection only happens when the user calls a gc_go_find_cycles()
function? Would that significantly improve the above numbers?

Yes, that would be possible, but it wouldn't speed anything up in case
you don't have any cycles.

Derick

17 years ago by Matthias Pigulla — view source

unread

Is it possible to always perform (unconditionally compile in) the
necessary housekeeping tasks but stick with the current GC, so that
cycle-detection only happens when the user calls a
gc_go_find_cycles()
function? Would that significantly improve the above numbers?

Yes, that would be possible, but it wouldn't speed anything up in case
you don't have any cycles.

Not sure I got you right. That is, the speed penalty comes from housekeeping? Does the new GC try to find cycles automatically whenever a refcount goes down to zero?

If building and maintaining data structures for the algorithm costs only a little memory but speed impact is neglegible unless the algorithm actually runs, then you could stick with the non-cycle-detecting "legacy" GC (= speed) unless you know you have cycles and/or want to trade a little processing time (a call to gc_go_find_cycles()) for the memory it will/might free.

-mp.

17 years ago by Derick Rethans — view source

unread

Is it possible to always perform (unconditionally compile in) the
necessary housekeeping tasks but stick with the current GC, so that
cycle-detection only happens when the user calls a
gc_go_find_cycles()
function? Would that significantly improve the above numbers?

Yes, that would be possible, but it wouldn't speed anything up in case
you don't have any cycles.

Not sure I got you right. That is, the speed penalty comes from
housekeeping? Does the new GC try to find cycles automatically
whenever a refcount goes down to zero?

Not immediately... the algorithm should only run when either the root
buffer is full, or the function is run manually.

If building and maintaining data structures for the algorithm costs
only a little memory but speed impact is neglegible unless the
algorithm actually runs, then you could stick with the
non-cycle-detecting "legacy" GC (= speed) unless you know you have
cycles and/or want to trade a little processing time (a call to
gc_go_find_cycles()) for the memory it will/might free.

Yes, exactly. But it's just as easy to turn automatic cleaning as well -
in that case the find cycle algorithm will kick in at some specific
amount of "freed" vars.

regards,
Derick

--
Derick Rethans
http://derickrethans.nl | http://ezcomponents.org | http://xdebug.org

17 years ago by Guilherme Blanco — view source

unread

I want to put my 2 cents, but before make any comment, I'm interested
to know if it's only a performance impact.

Talking about performance is ok and I agree that any penalty should be
taken into account, but if the patch uses less memory resources, I
think that shared hostings will care about it.
I remember when you released PHP 5_2, that was around 12% slower than
any version of PHP 4. None care about it, and only in PHP 5_2 you took
into account and optimized it a lot.

As long as it uses less memory, it should be added into 5_3. Wang
spent a lot of efforts to create the patch, Dmitry too.
Also, I think you should take care of 5% of performance penalty is not
huge if you consider that now you have a nice implementation of what
was not working correctly (referring to circular references).

But... if it uses more memory... I stay in the middle of the sides.
Too much more? This is a factor.

Besides all of this argumentation of performance... I'd go with Andi's
first suggestion. No config for it... in or out.
Make it configurable may generate some BC incompatibilities.

Regards,

I think having it configurable is a must. Turning it on / off via a compile flag will not suit everyone.

Eg - I have a situation where I would not want to run garbage collection for web pages served off my server due to the performance hit, however I also have a CLI script which I run to do complex, but repetitive tasks for ~half an hour.

Now this is not really a big deal to me as I managed to rid most of the leaks by nulling out cyclic references, however that took a lot of work which could have been avoided by this.

Could I suggest also enabling it by default for CLI?

SCOTT MCNAUGHT
Software Developer

Synergy 8 / +617 3397 5212
scott.mcnaught@synergy8.com

-----Original Message-----
From: Rasmus Lerdorf [mailto:rasmus@lerdorf.com]
Sent: Wednesday, 5 December 2007 5:17 AM
To: Antony Dovgal
Cc: Andi Gutmans; Cristian Rodriguez; internals@lists.php.net
Subject: Re: [PHP-DEV] Garbage collector patch

Antony Dovgal wrote:

You may be right longer term but shorter term I still believe there may be stability issues with this patch some of which we haven't figured out. Although we did testing and found crash bugs I wouldn't trust our level of testing to deem it stable. If we go down the route of always on we could have a hidden ini file (not listed in php.ini-dist and phpinfo()) which we can advise to turn off if something goes wrong and once we can enough confidence that there aren't any lurking bugs we could remove it.

You mean provide an ini setting to be able to turn it Off?
But why do you call it "always On" then?
And what's the difference comparing to what you've proposed earlier?

Concerning the stability issues, I'd say we have quite good chance
to make it stable enough, as (I hope) 5.3.0 is not going to be released
for at least several months more.

Companies that are especially concerned of performance/stability
are encouraged to step forward and give us a hand.

Companies concerned about performance aren't going to use it at all. A
5% hit is significant given that it doesn't fix anything that a company
already concerned about performance/stability cares about. Super leaky
or recursively allocating scripts have long since been weeded out of
those code bases, so it is a 5% performance hit with no gain.

I am not arguing that it isn't useful in the general case. It will make
PHP more robust on loosely controlled servers for what amounts to only a
small penalty, but at the same time it is an easy 5% win for people with
dedicated servers running well-written code.

-Rasmus

--

--

--
Guilherme Blanco - Web Developer
CBC - Certified Bindows Consultant
Cell Phone: +55 (16) 9166-6902
MSN: guilhermeblanco@hotmail.com
URL: http://blog.bisna.com
São Carlos - SP/Brazil

17 years ago by Andi Gutmans — view source

unread

Unfortunately it also takes more memory in the common case (at least the apps that we tested). It's not a significant amount more but it's a tiny bit more. I'd say negligible.
Btw, I think I miswrote in my email. When you look at the benchmark results on the new patch it's actually 1-2% slower and 0-3% more memory. I think even on a heavy duty server that is likely not to have much impact. I'm sure just the fluctuations between hardware architectures and compilers will often create bigger differences.

To clarify I meant there's a tri-state (not compiled in, compiled in but collection turned off, compiled in but collection turned on). My recommendation was to always compile it in but to keep collection turned off by default. I am also OK with trying to keep collection turned on as long as we have an INI parameter to turn it off when things go wrong (it can be hidden, i.e. doesn't show up in phpinfo() nor php.ini). Unfortunately there are certain areas of PHP which took more than a few months to stabilize. Not sure this would be the case here but better safe than sorry and have way to turn it off. You can never know what weird memory patterns in extensions and SAPI modules will lead to crashes.

Andi

-----Original Message-----
From: Guilherme Blanco [mailto:guilhermeblanco@gmail.com]
Sent: Tuesday, December 04, 2007 11:59 AM
To: scott.mcnaught@synergy8.com
Cc: Rasmus Lerdorf; Antony Dovgal; Andi Gutmans; Cristian Rodriguez;
internals@lists.php.net
Subject: Re: [PHP-DEV] Garbage collector patch

I want to put my 2 cents, but before make any comment, I'm interested
to know if it's only a performance impact.

Talking about performance is ok and I agree that any penalty should be
taken into account, but if the patch uses less memory resources, I
think that shared hostings will care about it.
I remember when you released PHP 5_2, that was around 12% slower than
any version of PHP 4. None care about it, and only in PHP 5_2 you took
into account and optimized it a lot.

As long as it uses less memory, it should be added into 5_3. Wang
spent a lot of efforts to create the patch, Dmitry too.
Also, I think you should take care of 5% of performance penalty is not
huge if you consider that now you have a nice implementation of what
was not working correctly (referring to circular references).

But... if it uses more memory... I stay in the middle of the sides.
Too much more? This is a factor.

Besides all of this argumentation of performance... I'd go with Andi's
first suggestion. No config for it... in or out.
Make it configurable may generate some BC incompatibilities.

Regards,

I think having it configurable is a must. Turning it on / off via a
compile flag will not suit everyone.

Eg - I have a situation where I would not want to run garbage
collection for web pages served off my server due to the performance
hit, however I also have a CLI script which I run to do complex, but
repetitive tasks for ~half an hour.

Now this is not really a big deal to me as I managed to rid most of
the leaks by nulling out cyclic references, however that took a lot of
work which could have been avoided by this.

Could I suggest also enabling it by default for CLI?

SCOTT MCNAUGHT
Software Developer

Synergy 8 / +617 3397 5212
scott.mcnaught@synergy8.com

-----Original Message-----
From: Rasmus Lerdorf [mailto:rasmus@lerdorf.com]
Sent: Wednesday, 5 December 2007 5:17 AM
To: Antony Dovgal
Cc: Andi Gutmans; Cristian Rodriguez; internals@lists.php.net
Subject: Re: [PHP-DEV] Garbage collector patch

Antony Dovgal wrote:

You may be right longer term but shorter term I still believe
there may be stability issues with this patch some of which we haven't
figured out. Although we did testing and found crash bugs I wouldn't
trust our level of testing to deem it stable. If we go down the route
of always on we could have a hidden ini file (not listed in php.ini-
dist and phpinfo()) which we can advise to turn off if something goes
wrong and once we can enough confidence that there aren't any lurking
bugs we could remove it.

You mean provide an ini setting to be able to turn it Off?
But why do you call it "always On" then?
And what's the difference comparing to what you've proposed
earlier?

Concerning the stability issues, I'd say we have quite good chance
to make it stable enough, as (I hope) 5.3.0 is not going to be
released
for at least several months more.

Companies that are especially concerned of performance/stability
are encouraged to step forward and give us a hand.

Companies concerned about performance aren't going to use it at all.
A
5% hit is significant given that it doesn't fix anything that a
company
already concerned about performance/stability cares about. Super
leaky
or recursively allocating scripts have long since been weeded out of
those code bases, so it is a 5% performance hit with no gain.

I am not arguing that it isn't useful in the general case. It will
make
PHP more robust on loosely controlled servers for what amounts to
only a
small penalty, but at the same time it is an easy 5% win for people
with
dedicated servers running well-written code.

-Rasmus

--

--

--
Guilherme Blanco - Web Developer
CBC - Certified Bindows Consultant
Cell Phone: +55 (16) 9166-6902
MSN: guilhermeblanco@hotmail.com
URL: http://blog.bisna.com
São Carlos - SP/Brazil

17 years ago by Derick Rethans — view source

unread

To clarify I meant there's a tri-state (not compiled in, compiled in
but collection turned off, compiled in but collection turned on). My
recommendation was to always compile it in but to keep collection
turned off by default.

That's totally fine with me. With David's patch you could turn it on
with both an ini setting (PHP_INI_ALL) or with a function. Can the
"improved" one do so as well?

regards,
Derick

Derick Rethans
http://derickrethans.nl | http://ezcomponents.org | http://xdebug.org

17 years ago by Stanislav Malyshev — view source

unread

To clarify I meant there's a tri-state (not compiled in, compiled in
but collection turned off, compiled in but collection turned on). My
recommendation was to always compile it in but to keep collection
turned off by default.

Do I understand it right that being compiled in, "turned on" and "turned
off" have the same performance implications (slightly slower, a little
bit more memory) and the difference is mainly stability-wise?

Stanislav Malyshev, Zend Software Architect
stas@zend.com http://www.zend.com/
(408)253-8829 MSN: stas@zend.com

17 years ago by Derick Rethans — view source

unread

To clarify I meant there's a tri-state (not compiled in, compiled in but
collection turned off, compiled in but collection turned on). My
recommendation was to always compile it in but to keep collection turned
off by default.

Do I understand it right that being compiled in, "turned on" and "turned off"
have the same performance implications (slightly slower, a little bit more
memory) and the difference is mainly stability-wise?

Yeah - atleast, that's how David's original patch behaved.

regards,
Derick

--
Derick Rethans
http://derickrethans.nl | http://ezcomponents.org | http://xdebug.org

17 years ago by Andi Gutmans — view source

unread

Yes that's basically true although Dmitry can probably elaborate. I believe if the collector kicks in there'll also be a bit of a slowdown but my main concern is to be able to turn it off because of stability. As you can see with the update patch it seems performance is quite good.
Anyway will circle back with Dmitry just to be sure.

Andi

-----Original Message-----
From: Derick Rethans [mailto:derick@php.net]
Sent: Wednesday, December 05, 2007 3:10 PM
To: Stas Malyshev
Cc: Andi Gutmans; Guilherme Blanco; scott.mcnaught@synergy8.com; Rasmus
Lerdorf; Antony Dovgal; Cristian Rodriguez; internals@lists.php.net
Subject: Re: [PHP-DEV] Garbage collector patch

To clarify I meant there's a tri-state (not compiled in, compiled
in but
collection turned off, compiled in but collection turned on). My
recommendation was to always compile it in but to keep collection
turned
off by default.

Do I understand it right that being compiled in, "turned on" and
"turned off"
have the same performance implications (slightly slower, a little bit
more
memory) and the difference is mainly stability-wise?

Yeah - atleast, that's how David's original patch behaved.

regards,
Derick

--
Derick Rethans
http://derickrethans.nl | http://ezcomponents.org | http://xdebug.org

17 years ago by Derick Rethans — view source

unread

Yes that's basically true although Dmitry can probably elaborate. I
believe if the collector kicks in there'll also be a bit of a slowdown
but my main concern is to be able to turn it off because of stability.
As you can see with the update patch it seems performance is quite
good.

From what I can see, the patch doesn't actually work... it just crashes.
Did you have a look at that yet?

regards,
Derick

Derick Rethans
http://derickrethans.nl | http://ezcomponents.org | http://xdebug.org

17 years ago by Antony Dovgal — view source

unread

Yes that's basically true although Dmitry can probably elaborate. I
believe if the collector kicks in there'll also be a bit of a slowdown
but my main concern is to be able to turn it off because of stability.
As you can see with the update patch it seems performance is quite
good.

From what I can see, the patch doesn't actually work... it just crashes.
Did you have a look at that yet?

To be honest, I can't see any crashes using standard PHP test suite.
Do you have a reproduce case or something?

--
Wbr,
Antony Dovgal

17 years ago by Sebastian Bergmann — view source

unread

Antony Dovgal schrieb:

To be honest, I can't see any crashes using standard PHP test suite.

Does the standard PHP test suite contain PHP code with reference cycles?

--
Sebastian Bergmann http://sebastian-bergmann.de/
GnuPG Key: 0xB85B5D69 / 27A7 2B14 09E4 98CD 6277 0E5B 6867 C514 B85B 5D69

17 years ago by Derick Rethans — view source

unread

Yes that's basically true although Dmitry can probably elaborate. I
believe if the collector kicks in there'll also be a bit of a slowdown
but my main concern is to be able to turn it off because of stability.
As you can see with the update patch it seems performance is quite
good.

From what I can see, the patch doesn't actually work... it just crashes.
Did you have a look at that yet?

To be honest, I can't see any crashes using standard PHP test suite.

That doesn't surprise me, as none of the tests there run really
complicated code.

Do you have a reproduce case or something?

Sure, it was in my original mail, but here it is again:

To reproduce, run the Template tests of the eZ Components:

mkdir ezc

cd ezc

svn co http://svn.ez.no/svn/ezcomponents/trunk

svn co http://svn.ez.no/svn/ezcomponents/scripts

./scripts/setup-env.sh

php UnitTest/src/run-tests.php Template

regards,
Derick

--
Derick Rethans
http://derickrethans.nl | http://ezcomponents.org | http://xdebug.org

17 years ago by Dmitry Stogov — view source

unread

The GC patch passes the whole php test-suite with the same bugs.

The fact that it crashes on some script doesn't mean that "the patch
doesn't actually work".

Thanks. Dmitry.

Derick Rethans wrote:

Yes that's basically true although Dmitry can probably elaborate. I
believe if the collector kicks in there'll also be a bit of a slowdown
but my main concern is to be able to turn it off because of stability.
As you can see with the update patch it seems performance is quite
good.

From what I can see, the patch doesn't actually work... it just crashes.
Did you have a look at that yet?

regards,
Derick

17 years ago by Derick Rethans — view source

unread

Derick Rethans wrote:

Yes that's basically true although Dmitry can probably elaborate.
I believe if the collector kicks in there'll also be a bit of a
slowdown but my main concern is to be able to turn it off because
of stability. As you can see with the update patch it seems
performance is quite good.

From what I can see, the patch doesn't actually work... it just
crashes. Did you have a look at that yet?

The GC patch passes the whole php test-suite with the same bugs.

The fact that it crashes on some script doesn't mean that "the patch doesn't
actually work".

That doesn't mean it works better for me than the old one either, where
I couldn't get it to crash at all ;-) Anyway, did you try to reproduce
it with the instructions that I provided?

regards,
Derick

Derick Rethans
http://derickrethans.nl | http://ezcomponents.org | http://xdebug.org

17 years ago by Dmitry Stogov — view source

unread

Derick Rethans wrote:

To clarify I meant there's a tri-state (not compiled in, compiled in
but collection turned off, compiled in but collection turned on). My
recommendation was to always compile it in but to keep collection
turned off by default.

That's totally fine with me. With David's patch you could turn it on
with both an ini setting (PHP_INI_ALL) or with a function. Can the
"improved" one do so as well?

The GC has two stages.

GC information collection (called very often during php script
execution and doesn't take a lot of time)
unreferenced cycle collection (called seldom but may take long time)

The original patch wrapped (1) and (2) with checks for GC on/off.
The "improved" one only (2).

The checks for GC on/off in original patch took just a bit less time
than the whole GC information collection in the "improved".

Thanks. Dmitry.

regards,
Derick

17 years ago by Dmitry Stogov — view source

unread

In general this patch will use more memory.
(4 bytes more for each heap allocated zval).

The only advantage is automatic cycle collection, but most web
applications doesn't make cycles.

Dmitry.

Guilherme Blanco wrote:

I want to put my 2 cents, but before make any comment, I'm interested
to know if it's only a performance impact.

Talking about performance is ok and I agree that any penalty should be
taken into account, but if the patch uses less memory resources, I
think that shared hostings will care about it.
I remember when you released PHP 5_2, that was around 12% slower than
any version of PHP 4. None care about it, and only in PHP 5_2 you took
into account and optimized it a lot.

As long as it uses less memory, it should be added into 5_3. Wang
spent a lot of efforts to create the patch, Dmitry too.
Also, I think you should take care of 5% of performance penalty is not
huge if you consider that now you have a nice implementation of what
was not working correctly (referring to circular references).

But... if it uses more memory... I stay in the middle of the sides.
Too much more? This is a factor.

Besides all of this argumentation of performance... I'd go with Andi's
first suggestion. No config for it... in or out.
Make it configurable may generate some BC incompatibilities.

Regards,

I think having it configurable is a must. Turning it on / off via a compile flag will not suit everyone.

Eg - I have a situation where I would not want to run garbage collection for web pages served off my server due to the performance hit, however I also have a CLI script which I run to do complex, but repetitive tasks for ~half an hour.

Now this is not really a big deal to me as I managed to rid most of the leaks by nulling out cyclic references, however that took a lot of work which could have been avoided by this.

Could I suggest also enabling it by default for CLI?

SCOTT MCNAUGHT
Software Developer

Synergy 8 / +617 3397 5212
scott.mcnaught@synergy8.com

-----Original Message-----
From: Rasmus Lerdorf [mailto:rasmus@lerdorf.com]
Sent: Wednesday, 5 December 2007 5:17 AM
To: Antony Dovgal
Cc: Andi Gutmans; Cristian Rodriguez; internals@lists.php.net
Subject: Re: [PHP-DEV] Garbage collector patch

Antony Dovgal wrote:

You may be right longer term but shorter term I still believe there may be stability issues with this patch some of which we haven't figured out. Although we did testing and found crash bugs I wouldn't trust our level of testing to deem it stable. If we go down the route of always on we could have a hidden ini file (not listed in php.ini-dist and phpinfo()) which we can advise to turn off if something goes wrong and once we can enough confidence that there aren't any lurking bugs we could remove it.
You mean provide an ini setting to be able to turn it Off?
But why do you call it "always On" then?
And what's the difference comparing to what you've proposed earlier?

Concerning the stability issues, I'd say we have quite good chance
to make it stable enough, as (I hope) 5.3.0 is not going to be released
for at least several months more.

Companies that are especially concerned of performance/stability
are encouraged to step forward and give us a hand.
Companies concerned about performance aren't going to use it at all. A
5% hit is significant given that it doesn't fix anything that a company
already concerned about performance/stability cares about. Super leaky
or recursively allocating scripts have long since been weeded out of
those code bases, so it is a 5% performance hit with no gain.

I am not arguing that it isn't useful in the general case. It will make
PHP more robust on loosely controlled servers for what amounts to only a
small penalty, but at the same time it is an easy 5% win for people with
dedicated servers running well-written code.

-Rasmus

17 years ago by Brian Moon — view source

unread

Dmitry Stogov wrote:

In general this patch will use more memory.
(4 bytes more for each heap allocated zval).

The only advantage is automatic cycle collection, but most web
applications doesn't make cycles.

Could it be that this code should only be enabled for the CLI sapi?
That is where I would want it most. Only in my cli apps do I run into
having to trick the garbage collection into working in my favor. I
usually end having my loop just call a function on each pass. That
seems to help with memory use in PHP currently.

--

Brian Moon
Senior Developer

http://dealnews.com/
It's good to be cheap =)

17 years ago by Robert Cummings — view source

unread

Dmitry Stogov wrote:

In general this patch will use more memory.
(4 bytes more for each heap allocated zval).

The only advantage is automatic cycle collection, but most web
applications doesn't make cycles.

Could it be that this code should only be enabled for the CLI sapi?
That is where I would want it most. Only in my cli apps do I run into
having to trick the garbage collection into working in my favor. I
usually end having my loop just call a function on each pass. That
seems to help with memory use in PHP currently.

Still comes down the issue of binary compatibility with respect to
modules and such.

Cheers,
Rob.

...........................................................
SwarmBuy.com - http://www.swarmbuy.com

Leveraging the buying power of the masses!

...........................................................

17 years ago by Derick Rethans — view source

unread

Derick Rethans wrote:

That doesn't mean it works better for me than the old one either, where I
couldn't get it to crash at all ;-) Anyway, did you try to reproduce it with
the instructions that I provided?

Yes I did. I'm looking into the crash.

I tested the updated patches now, it it's much better. I do however
still get an error:

Template:
ezcTemplateRegressionTest:
....................../home/derick/dev/php/php-5.3dev-gc/Zend/zend_hash.c(668)
: ht=0x3cc79338 is being destroyed

but only after running lots of tests[1]. I'll try to rerun it in GDB
to see whether I can get a backtrace, or through valgrind.

[1] ~/dev/php/php-5.3dev-gc/sapi/cli/php -dzend.enable_gc=1 UnitTest/src/runtests.php -c /home/httpd/html/report -D sqlite://:memory:

regards,
Derick

--
Derick Rethans
http://derickrethans.nl | http://ezcomponents.org | http://xdebug.org

17 years ago by Dmitry Stogov — view source

unread

hi Derick,

all your tests passed for me yesterday with memory_limit=1G.
May be it's some fresh non GC related bug :)
Try the same test with -dzend.enable_gc=0 and with unpatched PHP.

I would very interested in this "bad" test case, if it's really related
to GC.

Thanks. Dmitry.

Derick Rethans wrote:

Derick Rethans wrote:

That doesn't mean it works better for me than the old one either, where I
couldn't get it to crash at all ;-) Anyway, did you try to reproduce it with
the instructions that I provided?
Yes I did. I'm looking into the crash.

I tested the updated patches now, it it's much better. I do however
still get an error:

Template:
ezcTemplateRegressionTest:
....................../home/derick/dev/php/php-5.3dev-gc/Zend/zend_hash.c(668)
: ht=0x3cc79338 is being destroyed

but only after running lots of tests[1]. I'll try to rerun it in GDB
to see whether I can get a backtrace, or through valgrind.

[1] ~/dev/php/php-5.3dev-gc/sapi/cli/php -dzend.enable_gc=1 UnitTest/src/runtests.php -c /home/httpd/html/report -D sqlite://:memory:

regards,
Derick

17 years ago by Derick Rethans — view source

unread

all your tests passed for me yesterday with memory_limit=1G.
May be it's some fresh non GC related bug :)
Try the same test with -dzend.enable_gc=0 and with unpatched PHP.

I would very interested in this "bad" test case, if it's really related to GC.

I tried to run it, but unfortunately my machine ran out of memory before
it (that includes a full swapspace). I'd need access to a machine which
has more memory than I have for this (4gb minimal). If you have such a
machine, perhaps you can try yourself? Instead of running just the
Template tests, I ran all of them:

~/dev/php/php-5.3dev-gc/sapi/cli/php -dzend.enable_gc=1 UnitTest/src/runtests.php -c /home/httpd/html/report -D sqlite://:memory:

For -c to work, you will need xdebug installed though - I tried without
but got the same issue.

regards,
Derick

--
Derick Rethans
http://derickrethans.nl | http://ezcomponents.org | http://xdebug.org

17 years ago by Dmitry Stogov — view source

unread

Hi Derick,

You test are enormous, but than you anyway. :)
I've found and fixed the problem.

Now your test suite is passed with the following results:

PHP_5_3: Tests: 7706, Failures: 45, Errors: 807, Skipped: 347

With GC: Tests: 7706, Failures: 45, Errors: 804, Skipped: 347

I've no idea why GC fixes three tests. (I can send you logs if you like)

Thanks. Dmitry.

Derick Rethans wrote:

all your tests passed for me yesterday with memory_limit=1G.
May be it's some fresh non GC related bug :)
Try the same test with -dzend.enable_gc=0 and with unpatched PHP.

I would very interested in this "bad" test case, if it's really related to GC.

I tried to run it, but unfortunately my machine ran out of memory before
it (that includes a full swapspace). I'd need access to a machine which
has more memory than I have for this (4gb minimal). If you have such a
machine, perhaps you can try yourself? Instead of running just the
Template tests, I ran all of them:

~/dev/php/php-5.3dev-gc/sapi/cli/php -dzend.enable_gc=1 UnitTest/src/runtests.php -c /home/httpd/html/report -D sqlite://:memory:

For -c to work, you will need xdebug installed though - I tried without
but got the same issue.

regards,
Derick

17 years ago by Derick Rethans — view source

unread

You test are enormous, but than you anyway. :)
I've found and fixed the problem.

Now your test suite is passed with the following results:

PHP_5_3: Tests: 7706, Failures: 45, Errors: 807, Skipped: 347

With GC: Tests: 7706, Failures: 45, Errors: 804, Skipped: 347

I've no idea why GC fixes three tests. (I can send you logs if you like)

Yes, I'd appreciate that. And thanks for running them! Could you share
the updated patch as well please?

regards,
Derick

--
Derick Rethans
http://derickrethans.nl | http://ezcomponents.org | http://xdebug.org

17 years ago by Derick Rethans — view source

unread

You test are enormous, but than you anyway. :)
I've found and fixed the problem.

Now your test suite is passed with the following results:

PHP_5_3: Tests: 7706, Failures: 45, Errors: 807, Skipped: 347

With GC: Tests: 7706, Failures: 45, Errors: 804, Skipped: 347

I've no idea why GC fixes three tests. (I can send you logs if you like)

Yes, I'd appreciate that. And thanks for running them! Could you share
the updated patch as well please?

I'd like to play with it / test it - could you put the patch somewhere
please? And also the test logs as I am interested in why the GC patch
fixes things :)

regards,
Derick

--
Derick Rethans
http://derickrethans.nl | http://ezcomponents.org | http://xdebug.org

17 years ago by Dmitry Stogov — view source

unread

Didn't I send it to you?

Dmitry.

Derick Rethans wrote:

You test are enormous, but than you anyway. :)
I've found and fixed the problem.

Now your test suite is passed with the following results:

PHP_5_3: Tests: 7706, Failures: 45, Errors: 807, Skipped: 347

With GC: Tests: 7706, Failures: 45, Errors: 804, Skipped: 347

I've no idea why GC fixes three tests. (I can send you logs if you like)
Yes, I'd appreciate that. And thanks for running them! Could you share
the updated patch as well please?

I'd like to play with it / test it - could you put the patch somewhere
please? And also the test logs as I am interested in why the GC patch
fixes things :)

regards,
Derick

17 years ago by Derick Rethans — view source

unread

Didn't I send it to you?

Maybe, maybe not :) I couldn't find it atleast.
I just tried to apply this to PHP 5.3, but it gives lots of failed
chucks... Are you sure this is the one against 5.3?

regards,
Derick

--
Derick Rethans
http://derickrethans.nl | http://ezcomponents.org | http://xdebug.org

17 years ago by Dmitry Stogov — view source

unread

Probably I've changed ZE after the patch was done :(
I'll rebuild it, but not today.

Dmitry.

Derick Rethans wrote:

Didn't I send it to you?

Maybe, maybe not :) I couldn't find it atleast.
I just tried to apply this to PHP 5.3, but it gives lots of failed
chucks... Are you sure this is the one against 5.3?

regards,
Derick

17 years ago by Derick Rethans — view source

unread

Derick Rethans wrote:

Didn't I send it to you?

Maybe, maybe not :) I couldn't find it atleast.
I just tried to apply this to PHP 5.3, but it gives lots of failed chucks...
Are you sure this is the one against 5.3?

Probably I've changed ZE after the patch was done :(
I'll rebuild it, but not today.

Maybe we just should put it in cvs then? Then we won't have this issue
and other people can test it more easily as well.

regards,
Derick

--
Derick Rethans
http://derickrethans.nl | http://ezcomponents.org | http://xdebug.org

17 years ago by Alexey Zakhlestin — view source

unread

Maybe we just should put it in cvs then? Then we won't have this issue
and other people can test it more easily as well.

+1

I want to test it, but, usually, messing with large patches is too
time-consuming :-(
having it in CVS will give me a chance

--
Alexey Zakhlestin
http://blog.milkfarmsoft.com/

17 years ago by Dmitry Stogov — view source

unread

updated patch.

Dmitry.

Derick Rethans wrote:

Didn't I send it to you?

Maybe, maybe not :) I couldn't find it atleast.
I just tried to apply this to PHP 5.3, but it gives lots of failed
chucks... Are you sure this is the one against 5.3?

regards,
Derick

17 years ago by Derick Rethans — view source

unread

Derick Rethans wrote:

Didn't I send it to you?

Maybe, maybe not :) I couldn't find it atleast.
I just tried to apply this to PHP 5.3, but it gives lots of failed chucks...
Are you sure this is the one against 5.3?

updated patch.

Great, testing it now!

regards,
Derick

--
Derick Rethans
http://derickrethans.nl | http://ezcomponents.org | http://xdebug.org

17 years ago by Alexey Zakhlestin — view source

unread

updated patch.

got an error during linking phase

/usr/bin/ld: Undefined symbols:
_gc_globals_id
_gc_globals_ctor
_gc_zval_possible_root
_gc_collect_cycles
_gc_init
_gc_reset
_gc_zobj_possible_root
collect2: ld returned 1 exit status
make: *** [sapi/cli/php] Error 1

OS: MacOS-X 10.4.11, intel

--
Alexey Zakhlestin
http://blog.milkfarmsoft.com/

17 years ago by Antony Dovgal — view source

unread

updated patch.

got an error during linking phase

You have to run this first:
./cvsclean && ./buildconf

--
Wbr,
Antony Dovgal

17 years ago by Derick Rethans — view source

unread

updated patch.

got an error during linking phase

/usr/bin/ld: Undefined symbols:
_gc_globals_id
_gc_globals_ctor
_gc_zval_possible_root
_gc_collect_cycles
_gc_init
_gc_reset
_gc_zobj_possible_root
collect2: ld returned 1 exit status
make: *** [sapi/cli/php] Error 1

You have to re-run buildconf, it adds a zend_gc.c file.

regards,
Derick

17 years ago by Alexey Zakhlestin — view source

unread

updated patch.

Great! I managed to compile it.
Works for me.

The problem mentioned here is gone: http://blog.milkfarmsoft.com/?p=52
It is now possible to continue my appserver implementation ;)

--
Alexey Zakhlestin
http://blog.milkfarmsoft.com/

17 years ago by Markus Fischer — view source

unread

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

Hi,

it would really be great if this could be part of CVS alredy. The patch
doesn't compile currently, I get zillions of

Zend/zend_execute.o: In function gc_zval_check_possible_root': php5.3-200712250730/Zend/zend_gc.h:175: undefined reference togc_zval_possible_root'
Zend/zend_execute.o: In function gc_remove_from_buffer': php5.3-200712250730/Zend/zend_gc.h:183: undefined reference togc_globals'
php5.3-200712250730/Zend/zend_gc.h:184: undefined reference to gc_globals' php5.3-200712250730/Zend/zend_gc.h:183: undefined reference togc_globals'
php5.3-200712250730/Zend/zend_gc.h:184: undefined reference to `gc_globals'
collect2: ld returned 1 exit status

right now ...

- Markus

Dmitry Stogov wrote:

updated patch.

Dmitry.

Derick Rethans wrote:

Didn't I send it to you?

Maybe, maybe not :) I couldn't find it atleast.
I just tried to apply this to PHP 5.3, but it gives lots of failed
chucks... Are you sure this is the one against 5.3?

regards,
Derick

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17 years ago by Antony Dovgal — view source

unread

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

Hi,

it would really be great if this could be part of CVS alredy. The patch
doesn't compile currently, I get zillions of

You didn't read 3 last messages in the thread, did you?
You have to run ./buildconf && ./configure after applying the patch.

--
Wbr,
Antony Dovgal

17 years ago by Dmitry Stogov — view source

unread

./buildconf --force
./config.nice
make clean
make

Dmtiry.

Markus Fischer wrote:

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

Hi,

it would really be great if this could be part of CVS alredy. The patch
doesn't compile currently, I get zillions of

Zend/zend_execute.o: In function gc_zval_check_possible_root': php5.3-200712250730/Zend/zend_gc.h:175: undefined reference togc_zval_possible_root'
Zend/zend_execute.o: In function gc_remove_from_buffer': php5.3-200712250730/Zend/zend_gc.h:183: undefined reference togc_globals'
php5.3-200712250730/Zend/zend_gc.h:184: undefined reference to gc_globals' php5.3-200712250730/Zend/zend_gc.h:183: undefined reference togc_globals'
php5.3-200712250730/Zend/zend_gc.h:184: undefined reference to `gc_globals'
collect2: ld returned 1 exit status

right now ...

Markus

Dmitry Stogov wrote:

updated patch.

Dmitry.

Derick Rethans wrote:

Didn't I send it to you?
Maybe, maybe not :) I couldn't find it atleast.
I just tried to apply this to PHP 5.3, but it gives lots of failed
chucks... Are you sure this is the one against 5.3?

regards,
Derick

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Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org

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0pmCIOSo0irNjsqHELkjmwY=
=xtVx
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17 years ago by Markus Fischer — view source

unread

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

Ok, I got the message :-)

Sorry for interruption, thanks, works as expected.

- Markus
  
  Dmitry Stogov wrote:

./buildconf --force
./config.nice
make clean
make

Dmtiry.

Markus Fischer wrote:
Hi,

it would really be great if this could be part of CVS alredy. The patch
doesn't compile currently, I get zillions of

Zend/zend_execute.o: In function gc_zval_check_possible_root': php5.3-200712250730/Zend/zend_gc.h:175: undefined reference togc_zval_possible_root'
Zend/zend_execute.o: In function gc_remove_from_buffer': php5.3-200712250730/Zend/zend_gc.h:183: undefined reference togc_globals'
php5.3-200712250730/Zend/zend_gc.h:184: undefined reference to
gc_globals' php5.3-200712250730/Zend/zend_gc.h:183: undefined reference togc_globals'
php5.3-200712250730/Zend/zend_gc.h:184: undefined reference to
`gc_globals'
collect2: ld returned 1 exit status

right now ...

Markus

Dmitry Stogov wrote:

updated patch.

Dmitry.

Derick Rethans wrote:

Didn't I send it to you?
Maybe, maybe not :) I couldn't find it atleast.
I just tried to apply this to PHP 5.3, but it gives lots of failed
chucks... Are you sure this is the one against 5.3?

regards,
Derick

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Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org

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17 years ago by Dmitry Stogov — view source

unread

BTW the interesting fact that during Derick's test GC cycle collector
was automatically run 124 times and it collected 2,388,399 zvals.

So it really works! :)

Dmitry.

Dmitry Stogov wrote:

Hi Derick,

You test are enormous, but than you anyway. :)
I've found and fixed the problem.

Now your test suite is passed with the following results:

PHP_5_3: Tests: 7706, Failures: 45, Errors: 807, Skipped: 347

With GC: Tests: 7706, Failures: 45, Errors: 804, Skipped: 347

I've no idea why GC fixes three tests. (I can send you logs if you like)

Thanks. Dmitry.

Derick Rethans wrote:

all your tests passed for me yesterday with memory_limit=1G.
May be it's some fresh non GC related bug :)
Try the same test with -dzend.enable_gc=0 and with unpatched PHP.

I would very interested in this "bad" test case, if it's really
related to GC.

I tried to run it, but unfortunately my machine ran out of memory
before it (that includes a full swapspace). I'd need access to a
machine which has more memory than I have for this (4gb minimal). If
you have such a machine, perhaps you can try yourself? Instead of
running just the Template tests, I ran all of them:

~/dev/php/php-5.3dev-gc/sapi/cli/php -dzend.enable_gc=1
UnitTest/src/runtests.php -c /home/httpd/html/report -D sqlite://:memory:

For -c to work, you will need xdebug installed though - I tried
without but got the same issue.

regards,
Derick

17 years ago by Derick Rethans — view source

unread

Derick Rethans wrote:

Maybe we just should put it in cvs then? Then we won't have this issue
and other people can test it more easily as well.

The only problem with that is what if people get bad
benchmarks/results and we want to pull it out? It kind of defeats the
purpose to do this in a more structured way. Want us to commit it to a
branch? PHP 5.2.x?

Neither of those solve the merging issues, so no, not to a branch or
5.2. It should just go to HEAD and PHP_5_3. If it seems to be really
bad, we can always revert it later.

regards,
Derick

17 years ago by Andi Gutmans — view source

unread

Uhm I meant 5.3.
I guess we can commit it but as you know, reverting this kind of stuff later is a headache people don't like doing. With this patch it's not too bad because besides the macros which are committed already it's mostly isolated.

Only enough testing by people on the list will be able to give us additional information re: to the merits of this patch and how we should handle it. My hope people find it stable with negligible performance impact so that we can always keep it compiled in by default.
Andi

-----Original Message-----
From: Derick Rethans [mailto:derick@php.net]
Sent: Tuesday, December 18, 2007 9:20 AM
To: Andi Gutmans
Cc: Dmitry Stogov; PHP Developers Mailing List
Subject: RE: [PHP-DEV] Garbage collector patch

Derick Rethans wrote:

Maybe we just should put it in cvs then? Then we won't have this
issue
and other people can test it more easily as well.

The only problem with that is what if people get bad
benchmarks/results and we want to pull it out? It kind of defeats the
purpose to do this in a more structured way. Want us to commit it to
a
branch? PHP 5.2.x?

Neither of those solve the merging issues, so no, not to a branch or
5.2. It should just go to HEAD and PHP_5_3. If it seems to be really
bad, we can always revert it later.

regards,
Derick

17 years ago by Derick Rethans — view source

unread

Derick Rethans wrote:

Derick Rethans wrote:

Maybe we just should put it in cvs then? Then we won't have this
issue and other people can test it more easily as well.

The only problem with that is what if people get bad
benchmarks/results and we want to pull it out? It kind of defeats
the purpose to do this in a more structured way. Want us to commit
it to a branch? PHP 5.2.x?

Neither of those solve the merging issues, so no, not to a branch or
5.2. It should just go to HEAD and PHP_5_3. If it seems to be
really bad, we can always revert it later.

Uhm I meant 5.3. I guess we can commit it but as you know, reverting
this kind of stuff later is a headache people don't like doing.

Life's not always easy ;-)

regards,
Derick

--
Derick Rethans
http://derickrethans.nl | http://ezcomponents.org | http://xdebug.org

17 years ago by Stanislav Malyshev — view source

unread

Uhm I meant 5.3. I guess we can commit it but as you know, reverting
this kind of stuff later is a headache people don't like doing.

Life's not always easy ;-)

So why again life should be not easy for all PHP tree users and not only
for 3 people that work on the specific patch? CVS has branches just for
that purpose. Merging a branch is easy. Reverting a patch with changes
made over it is hard.

Stanislav Malyshev, Zend Software Architect
stas@zend.com http://www.zend.com/
(408)253-8829 MSN: stas@zend.com

17 years ago by johannes@php.net — view source

unread

Hi,

Uhm I meant 5.3.
I guess we can commit it but as you know, reverting this kind of stuff
later is a headache people don't like doing. With this patch it's not
too bad because besides the macros which are committed already it's mostly
isolated.

So can anybody do the commit then? Thanks.

Only enough testing by people on the list will be able to give us
additional information re: to the merits of this patch and how we
should handle it. My hope people find it stable with negligible
performance impact so that we can always keep it compiled in by default.

Right, and having it in CVS really helps having many people testing it
in different environments.

johannes

Andi

-----Original Message-----
From: Derick Rethans [mailto:derick@php.net]
Sent: Tuesday, December 18, 2007 9:20 AM
To: Andi Gutmans
Cc: Dmitry Stogov; PHP Developers Mailing List
Subject: RE: [PHP-DEV] Garbage collector patch

Derick Rethans wrote:

Maybe we just should put it in cvs then? Then we won't have this
issue
and other people can test it more easily as well.

The only problem with that is what if people get bad
benchmarks/results and we want to pull it out? It kind of defeats the
purpose to do this in a more structured way. Want us to commit it to
a
branch? PHP 5.2.x?

Neither of those solve the merging issues, so no, not to a branch or
5.2. It should just go to HEAD and PHP_5_3. If it seems to be really
bad, we can always revert it later.

regards,
Derick

17 years ago by Ilia Alshanetsky — view source

unread

Putting it into CVS into a good idea, but lets create a revert point
via a tag, so we can always easily "undo" the patch if need be.

Derick Rethans wrote:

Didn't I send it to you?

Maybe, maybe not :) I couldn't find it atleast.
I just tried to apply this to PHP 5.3, but it gives lots of failed
chucks...
Are you sure this is the one against 5.3?

Probably I've changed ZE after the patch was done :(
I'll rebuild it, but not today.

Maybe we just should put it in cvs then? Then we won't have this issue
and other people can test it more easily as well.

regards,
Derick

--
Derick Rethans
http://derickrethans.nl | http://ezcomponents.org | http://xdebug.org

--

Ilia Alshanetsky

17 years ago by Rasmus Lerdorf — view source

unread

Making sure it is ifdef'ed nicely would let us leave it in CVS until we
get it right and if it causes problems for some people they have a way
to build PHP without it. And yes, that means their build won't be
binary compatible, which is fine and no different from them trying to
revert the patch themselves.

-Rasmus

Ilia Alshanetsky wrote:

Putting it into CVS into a good idea, but lets create a revert point via
a tag, so we can always easily "undo" the patch if need be.

Derick Rethans wrote:

Didn't I send it to you?

Maybe, maybe not :) I couldn't find it atleast.
I just tried to apply this to PHP 5.3, but it gives lots of failed
chucks...
Are you sure this is the one against 5.3?

Probably I've changed ZE after the patch was done :(
I'll rebuild it, but not today.

Maybe we just should put it in cvs then? Then we won't have this issue
and other people can test it more easily as well.

regards,
Derick

--
Derick Rethans
http://derickrethans.nl | http://ezcomponents.org | http://xdebug.org

--

Ilia Alshanetsky

17 years ago by Stanislav Malyshev — view source

unread

Making sure it is ifdef'ed nicely would let us leave it in CVS until we
get it right and if it causes problems for some people they have a way

Why we need non-working code in main CVS ifdef'ed if we can use
perfectly good CVS branch functionality? Just to make life harder to
ourselves and the code harder to edit and understand?

Stanislav Malyshev, Zend Software Architect
stas@zend.com http://www.zend.com/
(408)253-8829 MSN: stas@zend.com

17 years ago by Derick Rethans — view source

unread

Ilia Alshanetsky wrote:

Putting it into CVS into a good idea, but lets create a revert point via
a tag, so we can always easily "undo" the patch if need be.

Making sure it is ifdef'ed nicely would let us leave it in CVS until we
get it right and if it causes problems for some people they have a way
to build PHP without it. And yes, that means their build won't be
binary compatible, which is fine and no different from them trying to
revert the patch themselves.

Both ideas sound like a good plan to me!

regards,
Derick

--
Derick Rethans
http://derickrethans.nl | http://ezcomponents.org | http://xdebug.org

17 years ago by Stanislav Malyshev — view source

unread

Putting it into CVS into a good idea, but lets create a revert point via
a tag, so we can always easily "undo" the patch if need be.

Along with undoing all patches on the way done by other people for othe
reasones. People, what's going on? Branches function in CVS is created
EXACTLY for this use case, why on Earth not to use it?

Stanislav Malyshev, Zend Software Architect
stas@zend.com http://www.zend.com/
(408)253-8829 MSN: stas@zend.com

Garbage collector patch

What is going to be eliminated, the slowdown? How?

mkdir ezc

cd ezc

svn co http://svn.ez.no/svn/ezcomponents/trunk

svn co http://svn.ez.no/svn/ezcomponents/scripts

./scripts/setup-env.sh

php UnitTest/src/run-tests.php Template

regards, Derick

Do I understand it right that being compiled in, "turned on" and "turned off" have the same performance implications (slightly slower, a little bit more memory) and the difference is mainly stability-wise?

regards, Derick

mkdir ezc

cd ezc

svn co http://svn.ez.no/svn/ezcomponents/trunk

svn co http://svn.ez.no/svn/ezcomponents/scripts

./scripts/setup-env.sh

php UnitTest/src/run-tests.php Template

regards, Derick

Brian Moon Senior Developer

Cheers, Rob.

So why again life should be not easy for all PHP tree users and not only for 3 people that work on the specific patch? CVS has branches just for that purpose. Merging a branch is easy. Reverting a patch with changes made over it is hard.

Why we need non-working code in main CVS ifdef'ed if we can use perfectly good CVS branch functionality? Just to make life harder to ourselves and the code harder to edit and understand?

Along with undoing all patches on the way done by other people for othe reasones. People, what's going on? Branches function in CVS is created EXACTLY for this use case, why on Earth not to use it?

regards,
Derick

Do I understand it right that being compiled in, "turned on" and "turned
off" have the same performance implications (slightly slower, a little
bit more memory) and the difference is mainly stability-wise?

regards,
Derick

regards,
Derick

Brian Moon
Senior Developer

Cheers,
Rob.

So why again life should be not easy for all PHP tree users and not only
for 3 people that work on the specific patch? CVS has branches just for
that purpose. Merging a branch is easy. Reverting a patch with changes
made over it is hard.

Why we need non-working code in main CVS ifdef'ed if we can use
perfectly good CVS branch functionality? Just to make life harder to
ourselves and the code harder to edit and understand?

Along with undoing all patches on the way done by other people for othe
reasones. People, what's going on? Branches function in CVS is created
EXACTLY for this use case, why on Earth not to use it?