Hi Mustapha, I have never seen such problems but I am no solver expert. What you can do:
* Do see this problem only in parallel or also in sequential code? Only with AMG or also with GMRES and ILU? * Reduce the problem as much as you can. The best would be a minimal piece of software that only depends on Dune-istl that reads in your matrix and repeatedly solves your linear system with the seen undesired memory consumption. Not sure whether this is possible and whether such minimal setup would still have the problem at all. When you reduce your current problem, the problem might vanish, too. This can help to find the cause of your issue. * Analyze the problem with Valgrind or AddressSanitizer. Having it reduced might be beneficial. * Turning on all compiler warnings and carefully evaluating them might help. But there are false positives but it can help. * Maybe its worth repeating your question at the Dune mailing list [email protected] as there are more Users and developers of istl. Bye, Christoph > Am 03.02.2017 um 11:14 schrieb Mustapha El Ossmani > <[email protected]>: > > > Dear DuMu^X developers, > > We are performing parallel computation with AMG solver. Due to problems of > convergence in the newton's method, in amgproperties.hh we set the > Preconditioner from Dune::SeqSSOR to Dune::SeqILU0 : > typedef Dune::BlockPreconditioner<VType,VType,Comm,Dune::SeqSSOR<MType,VType, > VType> > Smoother; > // typedef > Dune::BlockPreconditioner<VType,VType,Comm,Dune::SeqILU0<MType,VType, VType> > > Smoother; > It seems that there is some problems of memory loss with ILU0 > preconditionner. Indeed we can see that the memory of computation is > continually > increasing, until the computation stops with the following error message : > Solve: M deltax^k = rslurmstepd: Job 936902 exceeded memory limit (41146808 > > 41058304), being killed > slurmstepd: Exceeded job memory limit > > We can notice that this problem does not occur with SSOR as Preconditionner. > > Have you ever met this issue ? > Best regards > > M. El Ossmani > > University of Pau > _______________________________________________ > Dumux mailing list > [email protected] > https://listserv.uni-stuttgart.de/mailman/listinfo/dumux
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