Dear Paolo! Thanks a lot for this clearification! It finally got me to be able to use essl, though. I had to use -D__ESSL instead of D_LINUX_ESSL (suggested by ./configure)!
Finally a last question: Is is meaningfull to have the internal lapack loaded after the external one? I mean: LAPACK_LIBS = -lessl -L/gpfs/usrurz/lib64 -llapack /gpfs/home/aasfu/espresso-4.3.2/lapack-3.2/lapack.a vs. LAPACK_LIBS = -lessl -L/gpfs/usrurz/lib64 -llapack /gpfs/usrurz/lib64/liblapack.a beeing our local compiled version. Thank you, Guntram Am 27.07.2011 22:31, schrieb Paolo Giannozzi: > > On Jul 27, 2011, at 5:40 , Michael Sullivan wrote: > >> If I'm not wrong, that just means that you're not using ESSL. > > it is true that by linking lapack before essl, the lapack version > of lapack routines is linked, not the essl version. However > the fft and blas from essl are linked (unless there is a > copy of blas into lapack, which shouldn't be the case). > The resulting loss of performances should be minor. > If fft and blas from essl are not linked, the loss of > performances is much larger. > > Final clarification: > > -D__ESSL means that the fft routines of essl are used, and > that the calls of some lapack routines follow the essl syntax, > not the lapack syntax; > > -D__LINUX_ESSL means that the fft routines of essl are used, > and that the calls of lapack routines follow the lapack syntax. > > In all cases, it is convenient to link essl before lapack (essl does > not contain all lapack routines, just a subset, so not linking lapack > may result in missing symbols). If the lapack replacements in essl > do not follow the lapack syntax (IBM SP machines, typically), > -D__ESSL should be used. If they follow the lapack syntax, or if > they do not contain lapack replacements (IBM BlueGene and other > strange IBM machines), -D__LINUX_ESSL should be used. > > Complicated? blame the geniuses who wrote lapack replacements > with the same names but called in a different way > > P. > --- > Paolo Giannozzi, Dept of Chemistry&Physics&Environment, > Univ. Udine, via delle Scienze 208, 33100 Udine, Italy > Phone +39-0432-558216, fax +39-0432-558222 > > > > > _______________________________________________ > Pw_forum mailing list > Pw_forum at pwscf.org > http://www.democritos.it/mailman/listinfo/pw_forum
