Please remember to use "reply all" so messages go to the list.
On 5/31/2012 11:58 PM, 齐玉华 wrote:
Thanks for your quick reply again. It is probable that the valgrind
startup time to slow down the short-running scipt. I will validate it
later(the computer with linux installed is in laboratory).
Then, i seek to wrap some functions in php system to the patched ones
in a .so file. In this way, the recompilation time-overhead of the
patched php will be cut down. But to validate the candidate patch, we
need to regression testing <app:ds:%20%20regression%20testing>
(running the original php system with valgrind against numberous test
cases ). And the degradation due to valgrind will trade off the
recompilation-time cost reduction. Thus, if the valgrind startup time
can be somewhat reduced, the way to indirect the patched function will
have advantage of time-overhead.
Can you give me some advice to reduce the valgrind startup time?
Thanks very much.
I do not know whether valgrind startup time can be reduced; perhaps
Julian Seward (the author of valgrind) would know. I suspect the
answer is no; most programs spend much more time running than
initializing, so valgrind startup time has probably not been a concern
to anyone else.
I am not sure I understand your run-time concerns. You would be using
valgrind only during testing, so the penalty would be paid only during
testing. Will the tests fail simply because they are slower? Are there
so many tests that they will take substantially more than 20 minutes?
在 2012-06-01 14:03:14，"David Chapman" <dcchap...@acm.org> 写道：
On 5/31/2012 10:18 PM, 齐玉华 wrote:
Thanks for your quick reply. Here is the detailed information:
The good2.php is attached.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
grace@grace:~/software/WAutoRepair/experiment/php/php_null$
valgrind --version
valgrind-3.7.0
grace@grace:~/software/WAutoRepair/experiment/php/php_null$ uname -a
Linux grace 2.6.32-21-generic-pae #32-Ubuntu SMP Fri Apr 16
09:39:35 UTC 2010 i686 GNU/Linux
grace@grace:~/software/WAutoRepair/experiment/php/php_null$
/home/grace/software/WAutoRepair/experiment/php/php_null/php-src-5.3/sapi/cli/php
--version
PHP 5.3.7RC4-dev (cli) (built: May 21 2012 23:48:55)
Copyright (c) 1997-2011 The PHP Group
Zend Engine v2.3.0, Copyright (c) 1998-2011 Zend Technologies
grace@grace:~/software/WAutoRepair/experiment/php/php_null$time
/home/grace/software/WAutoRepair/experiment/php/php_null/php-src-5.3/sapi/cli/php
good2.php 6
real 0m0.009s
user 0m0.004s
sys 0m0.008s
grace@grace:~/software/WAutoRepair/experiment/php/php_null$time
valgrind --tool=none -q
/home/grace/software/WAutoRepair/experiment/php/php_null/php-src-5.3/sapi/cli/php
good2.php
6
real 0m1.086s
user 0m1.048s
sys 0m0.040s
This could very easily be valgrind startup time, not the slowdown
from valgrind's instruction simulator.
As requested by the previous post, please try "valgrind
--tool=none ls" and compare the run time with "ls" by itself.
grace@grace:~/software/WAutoRepair/experiment/php/php_null$time
/home/grace/software/WAutoRepair/experiment/php/php_null/php-src-5.3/sapi/cli/php
--version
PHP 5.3.7RC4-dev (cli) (built: May 21 2012 23:48:55)
Copyright (c) 1997-2011 The PHP Group
Zend Engine v2.3.0, Copyright (c) 1998-2011 Zend Technologies
real 0m0.008s
user 0m0.004s
sys 0m0.008s
grace@grace:~/software/WAutoRepair/experiment/php/php_null$ time
valgrind --tool=none -q
/home/grace/software/WAutoRepair/experiment/php/php_null/php-src-5.3/sapi/cli/php
--version
PHP 5.3.7RC4-dev (cli) (built: May 21 2012 23:48:55)
Copyright (c) 1997-2011 The PHP Group
Zend Engine v2.3.0, Copyright (c) 1998-2011 Zend Technologies
real 0m0.948s
user 0m0.904s
sys 0m0.044s
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
If the set of test cases are numerous(e.g. 1000), then the php
will incur significantly performance degradation. I am waiting in
hope for your insightful advices. Thanks again.
If your test cases run in 0.01 seconds each now but will run in 1
second under valgrind, 1000 tests will take about 20 minutes. Why
is this a problem? You won't be running valgrind every time you
launch PHP.
What happens when you run a large PHP script under valgrind? Do
you still see 25x or 100x slowdown?
在 2012-06-01 10:40:59，"John Reiser"<jrei...@bitwagon.com
<mailto:jrei...@bitwagon.com>> 写道：
>On 05/31/2012 07:10 PM, 齐玉华 wrote:
>> I try to use Valgrind to wrap some functions in target sotfwares such
as php, libtiff. But i found that valgrind will slow down them significantly(up to 25
times slowwer), even if run valgrind with '--tool=none'. And as described in valgrind
mannual, there should be 5 times slowwer than native
>> running. I am confused, so anyone can help me to reduce the
instrumentation-cost with some suggestions? I am waiting in hope for your advices.
Thanks.
>
>Please tell us the version of valgrind (the output of "valgrind --version"
>when fed to a shell), which hardware (x86_64, i686, PowerPC 64-bit, ARMv7,
>etc.), and which operating system and release (Ubuntu Linux 12.04, Android
4.1,
>MacOS 10.8 Darwin, etc.)
>
>How much slow-down do you observe for simple programs, such as
>"valgrind --tool=none date", or 'ls', 'who', etc?
>
>--
>
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