Hoang, I pushed a fix https://bitbucket.org/petsc/petsc/commits/d4e3277789d24018f0db1641a80db7be76600165 and added your test to petsc/src/ksp/ksp/examples/tests/ex53.c
It is on the branch hzhang/fix-blockedIS-submat Let me know if it still does not fix your problem. Hong On Sat, Jun 17, 2017 at 4:06 PM, Zhang, Hong <[email protected]> wrote: > never mind, I know it is ok to set blocksize=2 > ------------------------------ > *From:* Zhang, Hong > *Sent:* Saturday, June 17, 2017 3:56:35 PM > > *To:* Smith, Barry F.; Hoang Giang Bui > *Cc:* petsc-users > *Subject:* Re: [petsc-users] empty split for fieldsplit > > > Matrix A is a tridiagonal matrix with blocksize=1. > > Why do you set block_size=2 for A_IS and B_IS? > > > Hong > ------------------------------ > *From:* Zhang, Hong > *Sent:* Friday, June 16, 2017 7:55:45 AM > *To:* Smith, Barry F.; Hoang Giang Bui > *Cc:* petsc-users > *Subject:* Re: [petsc-users] empty split for fieldsplit > > > I'm in Boulder and will be back home this evening. > > Will test it this weekend. > > > Hong > ------------------------------ > *From:* Smith, Barry F. > *Sent:* Thursday, June 15, 2017 1:38:11 PM > *To:* Hoang Giang Bui; Zhang, Hong > *Cc:* petsc-users > *Subject:* Re: [petsc-users] empty split for fieldsplit > > > Hong, > > Please build the attached code with master and run with > > petscmpiexec -n 2 ./ex1 -mat_size 40 -block_size 2 -method 2 > > I think this is a bug in your new MatGetSubMatrix routines. You take the > block size of the outer IS and pass it into the inner IS but that inner IS > may not support the same block size hence the crash. > > Can you please debug this? > > Thanks > > Barry > > > > > On Jun 15, 2017, at 7:56 AM, Hoang Giang Bui <[email protected]> wrote: > > > > Hi Barry > > > > Thanks for pointing out the error. I think the problem coming from the > zero fieldsplit in proc 0. In this modified example, I parameterized the > matrix size and block size, so when you're executing > > > > mpirun -np 2 ./ex -mat_size 40 -block_size 2 -method 1 > > > > everything was fine. With method = 1, fieldsplit size of B is nonzero > and is divided by the block size. > > > > With method=2, i.e mpirun -np 2 ./ex -mat_size 40 -block_size 2 -method > 2, the fieldsplit B is zero on proc 0, and the error is thrown > > > > [1]PETSC ERROR: --------------------- Error Message > -------------------------------------------------------------- > > [1]PETSC ERROR: Arguments are incompatible > > [1]PETSC ERROR: Local size 11 not compatible with block size 2 > > > > This is somehow not logical, because 0 is divided by block_size. > > > > Furthermore, if you execute "mpirun -np 2 ./ex -mat_size 20 -block_size > 2 -method 2", the code hangs at ISSetBlockSize, which is pretty similar to > my original problem. Probably the original one also hangs at > ISSetBlockSize, which I may not realize at that time. > > > > Giang > > > > On Wed, Jun 14, 2017 at 5:29 PM, Barry Smith <[email protected]> wrote: > > > > You can't do this > > > > ierr = MatSetSizes(A,PETSC_DECIDE,N,N,N);CHKERRQ(ierr); > > > > use PETSC_DECIDE for the third argument > > > > Also this is wrong > > > > for (i = Istart; i < Iend; ++i) > > { > > ierr = MatSetValue(A,i,i,2,INSERT_VALUES);CHKERRQ(ierr); > > ierr = MatSetValue(A,i+1,i,-1,INSERT_VALUES);CHKERRQ(ierr); > > ierr = MatSetValue(A,i,i+1,-1,INSERT_VALUES);CHKERRQ(ierr); > > } > > > > you will get > > > > $ petscmpiexec -n 2 ./ex1 > > 0: Istart = 0, Iend = 60 > > 1: Istart = 60, Iend = 120 > > [1]PETSC ERROR: --------------------- Error Message > -------------------------------------------------------------- > > [1]PETSC ERROR: Argument out of range > > [1]PETSC ERROR: Row too large: row 120 max 119 > > [1]PETSC ERROR: See http://www.mcs.anl.gov/petsc/documentation/faq.html > for trouble shooting. > > [1]PETSC ERROR: Petsc Development GIT revision: v3.7.6-4103-g93161b8192 > GIT Date: 2017-06-11 14:49:39 -0500 > > [1]PETSC ERROR: ./ex1 on a arch-basic named Barrys-MacBook-Pro.local by > barrysmith Wed Jun 14 18:26:52 2017 > > [1]PETSC ERROR: Configure options PETSC_ARCH=arch-basic > > [1]PETSC ERROR: #1 MatSetValues_MPIAIJ() line 550 in > /Users/barrysmith/Src/petsc/src/mat/impls/aij/mpi/mpiaij.c > > [1]PETSC ERROR: #2 MatSetValues() line 1270 in > /Users/barrysmith/Src/petsc/src/mat/interface/matrix.c > > [1]PETSC ERROR: #3 main() line 30 in /Users/barrysmith/Src/petsc/ > test-dir/ex1.c > > [1]PETSC ERROR: PETSc Option Table entries: > > [1]PETSC ERROR: -malloc_test > > > > You need to get the example working so it ends with the error you > reported previously not these other bugs. > > > > > > > On Jun 12, 2017, at 10:19 AM, Hoang Giang Bui <[email protected]> > wrote: > > > > > > Dear Barry > > > > > > I made a small example with 2 process with one empty split in proc 0. > But it gives another strange error > > > > > > [1]PETSC ERROR: --------------------- Error Message > -------------------------------------------------------------- > > > [1]PETSC ERROR: Arguments are incompatible > > > [1]PETSC ERROR: Local size 31 not compatible with block size 2 > > > > > > The local size is always 60, so this is confusing. > > > > > > Giang > > > > > > On Sun, Jun 11, 2017 at 8:11 PM, Barry Smith <[email protected]> > wrote: > > > Could be, send us a simple example that demonstrates the problem and > we'll track it down. > > > > > > > > > > On Jun 11, 2017, at 12:34 PM, Hoang Giang Bui <[email protected]> > wrote: > > > > > > > > Hello > > > > > > > > I noticed that my code stopped very long, possibly hang, at > PCFieldSplitSetIS. There are two splits and one split is empty in one > process. May that be the possible reason that PCFieldSplitSetIS hang ? > > > > > > > > Giang > > > > > > > > > <ex.c> > > > > > > <ex.c> > >
