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<style> BODY { font-family:Arial, Helvetica, sans-serif;font-size:12px; }</style>Dear members,<br>
<br>
Currently I am porting CP code on BlueGene/L. I have met some problems that are <br>
related with libraries.<br>
The compilation and linking options are shown below<br>
./configure MPIF90=mpxlf90 CC=mpxlc F77=mpxlf LD=mpxlf90 <br>
LDFLAGS="-L/bgl/BlueLight/ppcfloor/bglsys/lib -lmpich.rts -lmsglayer.rts -lrts.rts -<br>
ldevices.rts"<br>
BLAS_LIBS="/bgl/local/lib/libblas440.a" <br>
LAPACK_LIBS="/bgl/local/lib/liblapack440.a /bgl/local/lib/scalapack/libscalapack.a" <br>
CFLAGS="-qarch=440 -qmaxmem=64000" <br>
FFLAGS="-qalias=noaryovrlp -I../include -O3 -qstrict -qarch=440d -qtune=440 -qsuffix=cpp=f90 -qdpc -qalias=nointpt" <br>
FFT_LIBS="/bgl/local/fftw-3.1.2/lib/libfftw3.a"<br>
<br>
There is not problem in obtaining cp.x when "make cp". We test 64 water using 256 <br>
processors(128 nodes) with number of task group equal to 2, and the speed of cp is 6 sec <br>
per step, which is good(If some of you have better suggestions for configuration which can lead to good performance, that will be so great). <br>
But we need to us cp-wf as well and find that wannier part takes also 6 sec per step, which is really <br>
unacceptable.We look into it and find that there are calls of DGEMM and ZHPEV which are quite time consuming(in wf.f90). For instance, ZHPEV takes 1.9sec per step and ZGEMM is 0.14 sec per step. Since ZGEMM and ZHPEV are both the calls in the library of LAPACK, we conclude it is because of bad choice of lapack library, is it correct?<br>
Currently the awkward situation is that there aren't ESSL libraries on our Blue Gene, but some others provided by an IBM'er as a part of the original training class. So I have little to do with this lapack library. And I have also searched our forum content a little bit and found few related result. I am not sure whether it is enough to choose the correct lapack library. Or we need a complete ESSL library so that the computing time of ZGEMM and ZHPEV can be decreased a lot. If it is the former case, can anyone who has lapack library of ESSL shares with me?<br>
Thank you in advance.<br>
<br>
best<br>
zhaofeng li<br>
<br>
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