[Digikam-users] Batch converter: can it use more than 1 cpu?

[sean darcy]

Gilles Caulier wrote:
> Batch Queue Manager already use multithreading, but not on multi core
> computer...
> 
> But...
> 
> about RAW conversion, libraw included in libkdcraw support
> parallelized demosaicing. You need to install OpenMp library and
> recompile libkdcraw.
> 
> Check in digiKam Help/Components Info to see if parallelized
> demosaicing is supported.
> 
> Gilles Caulier
> 
> 2009/12/27 sean darcy <seandarcy2 at gmail.com>:
>> On svn 1.1, I'm using the Raw Image batch converter on 35 images, on a
>> quad-core. top shows only 1 cpu being used.
>>
>> Is there a setting someplace that would enable threading? Or, if not
>> technically threading, where the converter converts as many images at
>> once as no_cpus?
>>
>> sean
>>

Well, I do have libgomp - OpenMP installed, and kdegraphics finds it:

CMake version (cleaned): cmake version 2.6.4
-- Try OpenMP C flag = [-fopenmp]
-- Performing Test OpenMP_FLAG_DETECTED
-- Performing Test OpenMP_FLAG_DETECTED - Success
-- Try OpenMP CXX flag = [-fopenmp]
-- Performing Test OpenMP_FLAG_DETECTED
-- Performing Test OpenMP_FLAG_DETECTED - Success
-- Found OpenMP: -fopenmp
-- OpenMP detected: LibRaw will be compiled with parallelized code.

But it looks like libRaw is NOT built with -fgomp:

[  7%] Building CXX object 
libs/libkdcraw/test/CMakeFiles/mem_image.dir/__/libraw/src/libraw_cxx.o
cd 
/home/photo/rpmbuild/BUILD/kdegraphics-4.3.3/x86_64-redhat-linux-gnu/libs/libkdcraw/test 
&& /usr/lib64/ccache/c++   -D_BSD_SOURCE -D_XOPEN_SOURCE=500 
-D_BSD_SOURCE -DQT_NO_STL -DQT_NO_CAST_TO_ASCII -D_REENTRANT 
-DKDE_DEPRECATED_WARNINGS -DUSE_LCMS -DDCRAW_VERBOSE -O3 -march=native 
-mtune=native -msse4.1 -ftree-vectorize -floop-interchange 
-floop-strip-mine -floop-block -mfpmath=sse  -Wnon-virtual-dtor 
-Wno-long-long -ansi -Wundef -Wcast-align -Wchar-subscripts -Wall -W 
-Wpointer-arith -Wformat-security -fno-exceptions -fno-check-new 
-fno-common -Woverloaded-virtual -fno-threadsafe-statics 
-fvisibility=hidden -fvisibility-inlines-hidden -O2 -DNDEBUG 
-DQT_NO_DEBUG 
-I/home/photo/rpmbuild/BUILD/kdegraphics-4.3.3/x86_64-redhat-linux-gnu/libs/libkdcraw/test 
-I/home/photo/rpmbuild/BUILD/kdegraphics-4.3.3/libs/libkdcraw/test 
-I/home/photo/rpmbuild/BUILD/kdegraphics-4.3.3 
-I/home/photo/rpmbuild/BUILD/kdegraphics-4.3.3/x86_64-redhat-linux-gnu 
-I/home/photo/rpmbuild/BUILD/kdegraphics-4.3.3/libs/libkdcraw/libraw 
-I/home/photo/rpmbuild/BUILD/kdegraphics-4.3.3/libs/libkdcraw/test/../libkdcraw 
-I/usr/include/kde4 -I/usr/include/kde4/KDE -I/usr/include/KDE 
-I/usr/include/QtXmlPatterns -I/usr/include/QtWebKit 
-I/usr/include/QtHelp -I/usr/include/QtAssistant -I/usr/include/QtDBus 
-I/usr/include/QtTest -I/usr/include/QtUiTools -I/usr/include/QtScript 
-I/usr/include/QtSvg -I/usr/include/QtXml -I/usr/include/QtSql 
-I/usr/include/QtOpenGL -I/usr/include/QtNetwork 
-I/usr/include/QtDesigner -I/usr/include/Qt3Support -I/usr/include/QtGui 
-I/usr/include/QtCore -I/usr/include/Qt -I/usr/lib64/qt4/mkspecs/default 
   -D_GNU_SOURCE -D_LARGEFILE64_SOURCE -fexceptions -DLIBRAW_BUILDLIB -w 
-o CMakeFiles/mem_image.dir/__/libraw/src/libraw_cxx.o -c 
/home/photo/rpmbuild/BUILD/kdegraphics-4.3.3/libs/libkdcraw/libraw/src/libraw_cxx.cpp

even though:

x86_64-redhat-linux-gnu/CMakeFiles/CMakeOutput.log:/usr/lib64/ccache/c++ 
    -O3 -march=native -mtune=native -msse4.1 -ftree-vectorize 
-floop-interchange -floop-strip-mine -floop-block -mfpmath=sse 
-Wnon-virtual-dtor -Wno-long-long -ansi -Wundef -Wcast-align 
-Wchar-subscripts -Wall -W -Wpointer-arith -Wformat-security 
-fno-exceptions -fno-check-new -fno-common -Woverloaded-virtual 
-fno-threadsafe-statics -fvisibility=hidden -fvisibility-inlines-hidden 
  -DOpenMP_FLAG_DETECTED -fopenmp  -fPIC 
CMakeFiles/cmTryCompileExec.dir/src.cxx.o  -o cmTryCompileExec -rdynamic

sean