Re: [QE-users] Does QE contain any OpenMP optimization ?
I apology for my ignorance ... I was using a Windows search based on following sequence: findstr /S /M "$OMP" *.* witch probably does not do the correct job (finding only 5 occurrence) ... grep -R '!$omp' . finally show me (as well as your sequence) the OpenMP optimization in the code is massive Homework for me - to find why OpenMP optimized build running on 4 CPU gives 100% identical performance as serial builds running on 1 core. The run of OpenMP build on 1 core is visible in task manager as well ... Maybe my gfortran is mad :-). Thank you for your patience Michal Husak From: users on behalf of Paolo Giannozzi Sent: Sunday, January 30, 2022 5:52 PM To: Quantum ESPRESSO users Forum Subject: Re: [QE-users] Does QE contain any OpenMP optimization ? On Sat, Jan 29, 2022 at 10:16 PM Husak Michal mailto:michal.hu...@vscht.cz>> wrote: I was searching for OpenMP optimization flags in QE fortran code like !$OMP PARALLEL etc ... But I did not find any in important source codes ... $ grep -i \$omp */*f90 */*/*f90| wc -l 1299 I guess that there are at least a few of the 1299 occurrences that have some effect. This is for the development version but it seems to me unlikely that all of them have appeared in the last two months Paolo -- Paolo Giannozzi, Dip. Scienze Matematiche Informatiche e Fisiche, Univ. Udine, via delle Scienze 206, 33100 Udine, Italy Phone +39-0432-558216, fax +39-0432-558222 ___ Quantum ESPRESSO is supported by MaX (www.max-centre.eu) users mailing list users@lists.quantum-espresso.org https://lists.quantum-espresso.org/mailman/listinfo/users
Re: [QE-users] Does QE contain any OpenMP optimization ?
On Sat, Jan 29, 2022 at 10:16 PM Husak Michal wrote: > I was searching for OpenMP optimization flags in QE fortran code like > > !$OMP PARALLEL etc ... > > But I did not find any in important source codes ... > $ grep -i \$omp */*f90 */*/*f90| wc -l 1299 I guess that there are at least a few of the 1299 occurrences that have some effect. This is for the development version but it seems to me unlikely that all of them have appeared in the last two months Paolo -- Paolo Giannozzi, Dip. Scienze Matematiche Informatiche e Fisiche, Univ. Udine, via delle Scienze 206, 33100 Udine, Italy Phone +39-0432-558216, fax +39-0432-558222 ___ Quantum ESPRESSO is supported by MaX (www.max-centre.eu) users mailing list users@lists.quantum-espresso.org https://lists.quantum-espresso.org/mailman/listinfo/users
Re: [QE-users] Does QE contain any OpenMP optimization ?
Most of the computationally expensive parts of QE have been progressively extracted from the code in the form of "libraries", which are parallelized both with MPI and openmp and mostly support GPU. Please have a look at this paper: https://arxiv.org/abs/2104.10502 kind regards -- Lorenzo Paulatto - Paris On Jan 29 2022, at 10:16 pm, Husak Michal wrote: > Hi > > > I was comparing the speed of QE build with > --enable-openmp > and > --disable-openmp > MPI was disabled ... > > From what I see OpenMP is activated but the speed gain is zero ... > I was searching for OpenMP optimization flags in QE fortran code like > !$OMP PARALLEL etc ... > But I did not find any in important source codes ... > Did I not catch something or is there really no OpenMP optimization in QE and > eventual MP speed up can be obtained only by the use of external (linear > algebra, fft) libraries ? > Michal Husak UCT Prague > ___ > Quantum ESPRESSO is supported by MaX (www.max-centre.eu) > users mailing list users@lists.quantum-espresso.org > https://lists.quantum-espresso.org/mailman/listinfo/users > ___ Quantum ESPRESSO is supported by MaX (www.max-centre.eu) users mailing list users@lists.quantum-espresso.org https://lists.quantum-espresso.org/mailman/listinfo/users
