[Insight-users] parallelization

[Mauro Maiorca]

Hi Dan & list,

I'm using
MattesMutualInformationImageToImageMetric
LinearInterpolateImageFunction

thanks for mentioning the IJ, it's an excellent source of info indeed!
However, according to the article "Optimizing ITK’s Registration
Methods for Multi-processor, Shared-Memory Systems" my code should be
optimized.
I would be really pleased to see any improvement on a multicore
architecture (even because I'm planning to register quite big volumes
using MMI).

Do you have any other clue/test/whatever to solve the problem?


cheers,
Mauro


On Fri, Sep 4, 2009 at 8:59 PM, Dan Mueller<dan.muel at gmail.com> wrote:
> Hi Mauro,
>
> Please report to the list what registration components you are using.
>
> ie. Linear Interpolator, Mattes Mutual Information Metric, Regular
> Step Gradient Descent.
>
> Only _some_ components have been optimized for parallelization. For
> which, please refer to the IJ article or the Code/Review folder (look
> for itkOpt*).
>
> Hope this helps.
>
> Cheers, Dan
>
> 2009/9/4 Mauro Maiorca <mauromaiorca at gmail.com>:
>> Thankyou very much Dan, John, and  Michael,
>>
>> I compiled again ITK with:
>> ITK_USE_OPTIMIZED_REGISTRATION_METHODS = ON
>> And still the same excecution time!
>>
>> I sent the task to only one processor (exec time 56'14") , four
>> processors (56'57"), and 8 processors (56'16"). Pretty much the same
>> time, no matter the number of processors involved in the computation.
>>
>> I also tried to add this to the ccmake of my application
>> CMAKE_CXX_FLAGS   -lpthread
>> It doesn't make any (significant) difference at all!
>>
>> any other clue?
>> cheers,
>> Mauro
>>
>>
>>
>> On Fri, Sep 4, 2009 at 1:10 AM, Dan Mueller<dan.muel at gmail.com> wrote:
>>> Hi Mauro,
>>>
>>> To make use of multiple cores for registration, please set the CMake variable
>>>    ITK_USE_OPTIMIZED_REGISTRATION_METHODS = ON
>>>
>>> This allows some interpolators/metrics to utilize multiple cores. For
>>> full details, please see:
>>>    http://www.insight-journal.org/browse/publication/172
>>>
>>> Hope this helps.
>>>
>>> Regards, Dan
>>>
>>> 2009/9/3 Mauro Maiorca <mauromaiorca at gmail.com>:
>>>> Hello list,
>>>>
>>>> I'm wondering whether the ITK code is optimized for running on a
>>>> multiprocessor machine?
>>>> I wrote a program to register 2 images but it is quite slow because of
>>>> many resamplings, so I'm running it on a 8 processor architecture ...
>>>> but no significant improvements.
>>>>
>>>> I'm using Itk 3.14 compiled (linux) with the following flags:
>>>>
>>>>  CMAKE_THREAD_LIBS                -lpthread
>>>>  CMAKE_USE_PTHREADS               ON
>>>>
>>>> any suggestion?
>>>>
>>>> cheers,
>>>> Mauro
>>>
>>
>