On Wed, Nov 29, 2023 at 1:55 PM Amneet Bhalla <mail2amn...@gmail.com> wrote:
> So the code logic is after the matrix is assembled, I iterate over all > distributed patches in the domain to see which of the patch is abutting a > Dirichlet boundary. Depending upon which patch abuts a physical and > Dirichlet boundary, a processor will call this routine. However, that same > processor is “owning” that DoF, which would be on its diagonal. > > I think Barry already mentioned this is not going to work unless I use the > flag to not communicate explicitly. However, that flag is not working as it > should over here for some reason. > Oh, I do not think that is right. Barry, when I look at the code, MPIU_Allreduce is always going to be called to fix up the nonzero_state. Am I wrong about that? Thanks, Matt > I can always change the matrix coefficients for Dirichlet rows during > MatSetValues. However, that would lengthen my code and I was trying to > avoid that. > > On Wed, Nov 29, 2023 at 10:02 AM Matthew Knepley <knep...@gmail.com> > wrote: > >> On Wed, Nov 29, 2023 at 12:30 PM Amneet Bhalla <mail2amn...@gmail.com> >> wrote: >> >>> Ok, I added both, but it still hangs. Here, is bt from all three tasks: >>> >> >> It looks like two processes are calling AllReduce, but one is not. Are >> all procs not calling MatZeroRows? >> >> Thanks, >> >> Matt >> >> >>> Task 1: >>> >>> amneetb@APSB-MacBook-Pro-16:~$ lldb -p 44691 >>> >>> (lldb) process attach --pid 44691 >>> >>> Process 44691 stopped >>> >>> * thread #1, queue = 'com.apple.main-thread', stop reason = signal >>> SIGSTOP >>> >>> frame #0: 0x000000018a2d750c >>> libsystem_kernel.dylib`__semwait_signal + 8 >>> >>> libsystem_kernel.dylib`: >>> >>> -> 0x18a2d750c <+8>: b.lo 0x18a2d752c ; <+40> >>> >>> 0x18a2d7510 <+12>: pacibsp >>> >>> 0x18a2d7514 <+16>: stp x29, x30, [sp, #-0x10]! >>> >>> 0x18a2d7518 <+20>: mov x29, sp >>> >>> Target 0: (fo_acoustic_streaming_solver_2d) stopped. >>> >>> Executable module set to >>> "/Users/amneetb/Softwares/IBAMR-Git/objs-dbg/tests/IBTK/fo_acoustic_streaming_solver_2d". >>> >>> Architecture set to: arm64-apple-macosx-. >>> >>> (lldb) cont >>> >>> Process 44691 resuming >>> >>> Process 44691 stopped >>> >>> * thread #1, queue = 'com.apple.main-thread', stop reason = signal >>> SIGSTOP >>> >>> frame #0: 0x000000010ba40b60 >>> libpmpi.12.dylib`MPIDI_POSIX_mpi_release_gather_release + 752 >>> >>> libpmpi.12.dylib`MPIDI_POSIX_mpi_release_gather_release: >>> >>> -> 0x10ba40b60 <+752>: add w8, w8, #0x1 >>> >>> 0x10ba40b64 <+756>: ldr w9, [x22] >>> >>> 0x10ba40b68 <+760>: cmp w8, w9 >>> >>> 0x10ba40b6c <+764>: b.lt 0x10ba40b4c ; <+732> >>> >>> Target 0: (fo_acoustic_streaming_solver_2d) stopped. >>> >>> (lldb) bt >>> >>> * thread #1, queue = 'com.apple.main-thread', stop reason = signal >>> SIGSTOP >>> >>> * frame #0: 0x000000010ba40b60 >>> libpmpi.12.dylib`MPIDI_POSIX_mpi_release_gather_release + 752 >>> >>> frame #1: 0x000000010ba48528 >>> libpmpi.12.dylib`MPIDI_POSIX_mpi_allreduce_release_gather + 1088 >>> >>> frame #2: 0x000000010ba47964 >>> libpmpi.12.dylib`MPIDI_Allreduce_intra_composition_gamma + 368 >>> >>> frame #3: 0x000000010ba35e78 libpmpi.12.dylib`MPIR_Allreduce + 1588 >>> >>> frame #4: 0x0000000103f587dc libmpi.12.dylib`MPI_Allreduce + 2280 >>> >>> frame #5: 0x0000000106d67650 >>> libpetsc.3.17.dylib`MatZeroRows_MPIAIJ(A=0x0000000105846470, N=1, >>> rows=0x000000016dbfa9f4, diag=1, x=0x0000000000000000, >>> b=0x0000000000000000) at mpiaij.c:827:3 >>> >>> frame #6: 0x0000000106aadfac >>> libpetsc.3.17.dylib`MatZeroRows(mat=0x0000000105846470, numRows=1, >>> rows=0x000000016dbfa9f4, diag=1, x=0x0000000000000000, >>> b=0x0000000000000000) at matrix.c:5935:3 >>> >>> frame #7: 0x00000001023952d0 >>> fo_acoustic_streaming_solver_2d`IBAMR::AcousticStreamingPETScMatUtilities::constructPatchLevelFOAcousticStreamingOp(mat=0x000000016dc04168, >>> omega=1, sound_speed=1, rho_idx=3, mu_idx=2, lambda_idx=4, >>> u_bc_coefs=0x000000016dc04398, data_time=NaN, num_dofs_per_proc=size=3, >>> u_dof_index_idx=27, p_dof_index_idx=28, >>> patch_level=Pointer<SAMRAI::hier::PatchLevel<2> > @ 0x000000016dbfcec0, >>> mu_interp_type=VC_HARMONIC_INTERP) at >>> AcousticStreamingPETScMatUtilities.cpp:799:36 >>> >>> frame #8: 0x00000001023acb8c >>> fo_acoustic_streaming_solver_2d`IBAMR::FOAcousticStreamingPETScLevelSolver::initializeSolverStateSpecialized(this=0x000000016dc04018, >>> x=0x000000016dc05778, (null)=0x000000016dc05680) at >>> FOAcousticStreamingPETScLevelSolver.cpp:149:5 >>> >>> frame #9: 0x000000010254a2dc >>> fo_acoustic_streaming_solver_2d`IBTK::PETScLevelSolver::initializeSolverState(this=0x000000016dc04018, >>> x=0x000000016dc05778, b=0x000000016dc05680) at PETScLevelSolver.cpp:340: >>> 5 >>> >>> frame #10: 0x0000000102202e5c >>> fo_acoustic_streaming_solver_2d`main(argc=11, argv=0x000000016dc07450) at >>> fo_acoustic_streaming_solver.cpp:400:22 >>> >>> frame #11: 0x0000000189fbbf28 dyld`start + 2236 >>> >>> (lldb) >>> >>> >>> Task 2: >>> >>> amneetb@APSB-MacBook-Pro-16:~$ lldb -p 44692 >>> >>> (lldb) process attach --pid 44692 >>> >>> Process 44692 stopped >>> >>> * thread #1, queue = 'com.apple.main-thread', stop reason = signal >>> SIGSTOP >>> >>> frame #0: 0x000000018a2d750c >>> libsystem_kernel.dylib`__semwait_signal + 8 >>> >>> libsystem_kernel.dylib`: >>> >>> -> 0x18a2d750c <+8>: b.lo 0x18a2d752c ; <+40> >>> >>> 0x18a2d7510 <+12>: pacibsp >>> >>> 0x18a2d7514 <+16>: stp x29, x30, [sp, #-0x10]! >>> >>> 0x18a2d7518 <+20>: mov x29, sp >>> >>> Target 0: (fo_acoustic_streaming_solver_2d) stopped. >>> >>> Executable module set to >>> "/Users/amneetb/Softwares/IBAMR-Git/objs-dbg/tests/IBTK/fo_acoustic_streaming_solver_2d". >>> >>> Architecture set to: arm64-apple-macosx-. >>> >>> (lldb) cont >>> >>> Process 44692 resuming >>> >>> Process 44692 stopped >>> >>> * thread #1, queue = 'com.apple.main-thread', stop reason = signal >>> SIGSTOP >>> >>> frame #0: 0x000000010e5a022c >>> libpmpi.12.dylib`MPIDI_POSIX_mpi_barrier_release_gather + 516 >>> >>> libpmpi.12.dylib`MPIDI_POSIX_mpi_barrier_release_gather: >>> >>> -> 0x10e5a022c <+516>: ldr x10, [x19, #0x4e8] >>> >>> 0x10e5a0230 <+520>: cmp x9, x10 >>> >>> 0x10e5a0234 <+524>: b.hs 0x10e5a0254 ; <+556> >>> >>> 0x10e5a0238 <+528>: add w8, w8, #0x1 >>> >>> Target 0: (fo_acoustic_streaming_solver_2d) stopped. >>> >>> (lldb) bt >>> >>> * thread #1, queue = 'com.apple.main-thread', stop reason = signal >>> SIGSTOP >>> >>> * frame #0: 0x000000010e5a022c >>> libpmpi.12.dylib`MPIDI_POSIX_mpi_barrier_release_gather + 516 >>> >>> frame #1: 0x000000010e59fd14 libpmpi.12.dylib`MPIDI_SHM_mpi_barrier >>> + 224 >>> >>> frame #2: 0x000000010e59fb60 >>> libpmpi.12.dylib`MPIDI_Barrier_intra_composition_alpha + 44 >>> >>> frame #3: 0x000000010e585490 libpmpi.12.dylib`MPIR_Barrier + 900 >>> >>> frame #4: 0x0000000106ac5030 libmpi.12.dylib`MPI_Barrier + 684 >>> >>> frame #5: 0x0000000108e62638 >>> libpetsc.3.17.dylib`PetscCommDuplicate(comm_in=1140850688, >>> comm_out=0x00000001408ae4b0, first_tag=0x00000001408ae4e4) at tagm.c:235 >>> :5 >>> >>> frame #6: 0x0000000108e6a910 >>> libpetsc.3.17.dylib`PetscHeaderCreate_Private(h=0x00000001408ae470, >>> classid=1211228, class_name="KSP", descr="Krylov Method", mansec="KSP", >>> comm=1140850688, destroy=(libpetsc.3.17.dylib`KSPDestroy at itfunc.c:1418), >>> view=(libpetsc.3.17.dylib`KSPView at itcreate.c:113)) at inherit.c:62:3 >>> >>> frame #7: 0x000000010aa28010 >>> libpetsc.3.17.dylib`KSPCreate(comm=1140850688, inksp=0x000000016b0a4160) at >>> itcreate.c:679:3 >>> >>> frame #8: 0x00000001050aa2f4 >>> fo_acoustic_streaming_solver_2d`IBTK::PETScLevelSolver::initializeSolverState(this=0x000000016b0a4018, >>> x=0x000000016b0a5778, b=0x000000016b0a5680) at PETScLevelSolver.cpp:344: >>> 12 >>> >>> frame #9: 0x0000000104d62e5c >>> fo_acoustic_streaming_solver_2d`main(argc=11, argv=0x000000016b0a7450) at >>> fo_acoustic_streaming_solver.cpp:400:22 >>> >>> frame #10: 0x0000000189fbbf28 dyld`start + 2236 >>> >>> (lldb) >>> >>> >>> Task 3: >>> >>> amneetb@APSB-MacBook-Pro-16:~$ lldb -p 44693 >>> >>> (lldb) process attach --pid 44693 >>> >>> Process 44693 stopped >>> >>> * thread #1, queue = 'com.apple.main-thread', stop reason = signal >>> SIGSTOP >>> >>> frame #0: 0x000000018a2d750c >>> libsystem_kernel.dylib`__semwait_signal + 8 >>> >>> libsystem_kernel.dylib`: >>> >>> -> 0x18a2d750c <+8>: b.lo 0x18a2d752c ; <+40> >>> >>> 0x18a2d7510 <+12>: pacibsp >>> >>> 0x18a2d7514 <+16>: stp x29, x30, [sp, #-0x10]! >>> >>> 0x18a2d7518 <+20>: mov x29, sp >>> >>> Target 0: (fo_acoustic_streaming_solver_2d) stopped. >>> >>> Executable module set to >>> "/Users/amneetb/Softwares/IBAMR-Git/objs-dbg/tests/IBTK/fo_acoustic_streaming_solver_2d". >>> >>> Architecture set to: arm64-apple-macosx-. >>> >>> (lldb) cont >>> >>> Process 44693 resuming >>> >>> Process 44693 stopped >>> >>> * thread #1, queue = 'com.apple.main-thread', stop reason = signal >>> SIGSTOP >>> >>> frame #0: 0x000000010e59c68c >>> libpmpi.12.dylib`MPIDI_POSIX_mpi_release_gather_gather + 952 >>> >>> libpmpi.12.dylib`MPIDI_POSIX_mpi_release_gather_gather: >>> >>> -> 0x10e59c68c <+952>: ldr w9, [x21] >>> >>> 0x10e59c690 <+956>: cmp w8, w9 >>> >>> 0x10e59c694 <+960>: b.lt 0x10e59c670 ; <+924> >>> >>> 0x10e59c698 <+964>: bl 0x10e59ce64 ; >>> MPID_Progress_test >>> >>> Target 0: (fo_acoustic_streaming_solver_2d) stopped. >>> >>> (lldb) bt >>> >>> * thread #1, queue = 'com.apple.main-thread', stop reason = signal >>> SIGSTOP >>> >>> * frame #0: 0x000000010e59c68c >>> libpmpi.12.dylib`MPIDI_POSIX_mpi_release_gather_gather + 952 >>> >>> frame #1: 0x000000010e5a44bc >>> libpmpi.12.dylib`MPIDI_POSIX_mpi_allreduce_release_gather + 980 >>> >>> frame #2: 0x000000010e5a3964 >>> libpmpi.12.dylib`MPIDI_Allreduce_intra_composition_gamma + 368 >>> >>> frame #3: 0x000000010e591e78 libpmpi.12.dylib`MPIR_Allreduce + 1588 >>> >>> frame #4: 0x0000000106ab47dc libmpi.12.dylib`MPI_Allreduce + 2280 >>> >>> frame #5: 0x00000001098c3650 >>> libpetsc.3.17.dylib`MatZeroRows_MPIAIJ(A=0x0000000136862270, N=1, >>> rows=0x000000016b09e9f4, diag=1, x=0x0000000000000000, >>> b=0x0000000000000000) at mpiaij.c:827:3 >>> >>> frame #6: 0x0000000109609fac >>> libpetsc.3.17.dylib`MatZeroRows(mat=0x0000000136862270, numRows=1, >>> rows=0x000000016b09e9f4, diag=1, x=0x0000000000000000, >>> b=0x0000000000000000) at matrix.c:5935:3 >>> >>> frame #7: 0x0000000104ef12d0 >>> fo_acoustic_streaming_solver_2d`IBAMR::AcousticStreamingPETScMatUtilities::constructPatchLevelFOAcousticStreamingOp(mat=0x000000016b0a8168, >>> omega=1, sound_speed=1, rho_idx=3, mu_idx=2, lambda_idx=4, >>> u_bc_coefs=0x000000016b0a8398, data_time=NaN, num_dofs_per_proc=size=3, >>> u_dof_index_idx=27, p_dof_index_idx=28, >>> patch_level=Pointer<SAMRAI::hier::PatchLevel<2> > @ 0x000000016b0a0ec0, >>> mu_interp_type=VC_HARMONIC_INTERP) at >>> AcousticStreamingPETScMatUtilities.cpp:799:36 >>> >>> frame #8: 0x0000000104f08b8c >>> fo_acoustic_streaming_solver_2d`IBAMR::FOAcousticStreamingPETScLevelSolver::initializeSolverStateSpecialized(this=0x000000016b0a8018, >>> x=0x000000016b0a9778, (null)=0x000000016b0a9680) at >>> FOAcousticStreamingPETScLevelSolver.cpp:149:5 >>> >>> frame #9: 0x00000001050a62dc >>> fo_acoustic_streaming_solver_2d`IBTK::PETScLevelSolver::initializeSolverState(this=0x000000016b0a8018, >>> x=0x000000016b0a9778, b=0x000000016b0a9680) at PETScLevelSolver.cpp:340: >>> 5 >>> >>> frame #10: 0x0000000104d5ee5c >>> fo_acoustic_streaming_solver_2d`main(argc=11, argv=0x000000016b0ab450) at >>> fo_acoustic_streaming_solver.cpp:400:22 >>> >>> frame #11: 0x0000000189fbbf28 dyld`start + 2236 >>> >>> (lldb) >>> >>> >>> On Wed, Nov 29, 2023 at 7:22 AM Barry Smith <bsm...@petsc.dev> wrote: >>> >>>> >>>> >>>> On Nov 29, 2023, at 1:16 AM, Amneet Bhalla <mail2amn...@gmail.com> >>>> wrote: >>>> >>>> BTW, I think you meant using MatSetOption(mat, >>>> *MAT_NO_OFF_PROC_ZERO_ROWS*, PETSC_TRUE) >>>> >>>> >>>> Yes >>>> >>>> instead ofMatSetOption(mat, *MAT_NO_OFF_PROC_ENTRIES*, PETSC_TRUE) ?? >>>> >>>> >>>> Please try setting both flags. >>>> >>>> However, that also did not help to overcome the MPI Barrier issue. >>>> >>>> >>>> If there is still a problem please trap all the MPI processes when >>>> they hang in the debugger and send the output from using bt on all of them. >>>> This way >>>> we can see the different places the different MPI processes are stuck >>>> at. >>>> >>>> >>>> >>>> On Tue, Nov 28, 2023 at 9:57 PM Amneet Bhalla <mail2amn...@gmail.com> >>>> wrote: >>>> >>>>> I added that option but the code still gets stuck at the same call >>>>> MatZeroRows with 3 processors. >>>>> >>>>> On Tue, Nov 28, 2023 at 7:23 PM Amneet Bhalla <mail2amn...@gmail.com> >>>>> wrote: >>>>> >>>>>> >>>>>> >>>>>> On Tue, Nov 28, 2023 at 6:42 PM Barry Smith <bsm...@petsc.dev> wrote: >>>>>> >>>>>>> >>>>>>> for (int comp = 0; comp < 2; ++comp) >>>>>>> { >>>>>>> ....... >>>>>>> for (Box<NDIM>::Iterator bc(bc_coef_box); bc; >>>>>>> bc++) >>>>>>> { >>>>>>> ...... >>>>>>> if (IBTK::abs_equal_eps(b, 0.0)) >>>>>>> { >>>>>>> const double diag_value = a; >>>>>>> ierr = MatZeroRows(mat, 1, &u_dof_index, >>>>>>> diag_value, NULL, NULL); >>>>>>> IBTK_CHKERRQ(ierr); >>>>>>> } >>>>>>> } >>>>>>> } >>>>>>> >>>>>>> In general, this code will not work because each process calls >>>>>>> MatZeroRows a different number of times, so it cannot match up with all >>>>>>> the >>>>>>> processes. >>>>>>> >>>>>>> If u_dof_index is always local to the current process, you can call >>>>>>> MatSetOption(mat, MAT_NO_OFF_PROC_ENTRIES,PETSC_TRUE) above the for loop >>>>>>> and >>>>>>> the MatZeroRows will not synchronize across the MPI processes (since >>>>>>> it does not need to and you told it that). >>>>>>> >>>>>> >>>>>> Yes, u_dof_index is going to be local and I put a check on it a few >>>>>> lines before calling MatZeroRows. >>>>>> >>>>>> Can MatSetOption() be called after the matrix has been assembled? >>>>>> >>>>>> >>>>>>> If the u_dof_index will not always be local, then you need, on each >>>>>>> process, to list all the u_dof_index for each process in an array and >>>>>>> then >>>>>>> call MatZeroRows() >>>>>>> once after the loop so it can exchange the needed information with >>>>>>> the other MPI processes to get the row indices to the right place. >>>>>>> >>>>>>> Barry >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> On Nov 28, 2023, at 6:44 PM, Amneet Bhalla <mail2amn...@gmail.com> >>>>>>> wrote: >>>>>>> >>>>>>> >>>>>>> Hi Folks, >>>>>>> >>>>>>> I am using MatZeroRows() to set Dirichlet boundary conditions. This >>>>>>> works fine for the serial run and the solver produces correct results >>>>>>> (verified through analytical solution). However, when I run the case in >>>>>>> parallel, the simulation gets stuck at MatZeroRows(). My understanding >>>>>>> is >>>>>>> that this function needs to be called after the MatAssemblyBegin{End}() >>>>>>> has >>>>>>> been called, and should be called by all processors. Here is that bit of >>>>>>> the code which calls MatZeroRows() after the matrix has been assembled >>>>>>> >>>>>>> >>>>>>> https://github.com/IBAMR/IBAMR/blob/amneetb/acoustically-driven-flows/src/acoustic_streaming/AcousticStreamingPETScMatUtilities.cpp#L724-L801 >>>>>>> >>>>>>> I ran the parallel code (on 3 processors) in the debugger >>>>>>> (-start_in_debugger). Below is the call stack from the processor that >>>>>>> gets >>>>>>> stuck >>>>>>> >>>>>>> amneetb@APSB-MBP-16:~$ lldb -p 4307 >>>>>>> (lldb) process attach --pid 4307 >>>>>>> Process 4307 stopped >>>>>>> * thread #1, queue = 'com.apple.main-thread', stop reason = signal >>>>>>> SIGSTOP >>>>>>> frame #0: 0x000000018a2d750c >>>>>>> libsystem_kernel.dylib`__semwait_signal + 8 >>>>>>> libsystem_kernel.dylib`: >>>>>>> -> 0x18a2d750c <+8>: b.lo 0x18a2d752c ; <+40> >>>>>>> 0x18a2d7510 <+12>: pacibsp >>>>>>> 0x18a2d7514 <+16>: stp x29, x30, [sp, #-0x10]! >>>>>>> 0x18a2d7518 <+20>: mov x29, sp >>>>>>> Target 0: (fo_acoustic_streaming_solver_2d) stopped. >>>>>>> Executable module set to >>>>>>> "/Users/amneetb/Softwares/IBAMR-Git/objs-dbg/tests/IBTK/fo_acoustic_streaming_solver_2d". >>>>>>> Architecture set to: arm64-apple-macosx-. >>>>>>> (lldb) cont >>>>>>> Process 4307 resuming >>>>>>> Process 4307 stopped >>>>>>> * thread #1, queue = 'com.apple.main-thread', stop reason = signal >>>>>>> SIGSTOP >>>>>>> frame #0: 0x0000000109d281b8 >>>>>>> libpmpi.12.dylib`MPIDI_POSIX_mpi_barrier_release_gather + 400 >>>>>>> libpmpi.12.dylib`MPIDI_POSIX_mpi_barrier_release_gather: >>>>>>> -> 0x109d281b8 <+400>: ldr w9, [x24] >>>>>>> 0x109d281bc <+404>: cmp w8, w9 >>>>>>> 0x109d281c0 <+408>: b.lt 0x109d281a0 ; <+376> >>>>>>> 0x109d281c4 <+412>: bl 0x109d28e64 ; >>>>>>> MPID_Progress_test >>>>>>> Target 0: (fo_acoustic_streaming_solver_2d) stopped. >>>>>>> (lldb) bt >>>>>>> * thread #1, queue = 'com.apple.main-thread', stop reason = signal >>>>>>> SIGSTOP >>>>>>> * frame #0: 0x0000000109d281b8 >>>>>>> libpmpi.12.dylib`MPIDI_POSIX_mpi_barrier_release_gather + 400 >>>>>>> frame #1: 0x0000000109d27d14 >>>>>>> libpmpi.12.dylib`MPIDI_SHM_mpi_barrier + 224 >>>>>>> frame #2: 0x0000000109d27b60 >>>>>>> libpmpi.12.dylib`MPIDI_Barrier_intra_composition_alpha + 44 >>>>>>> frame #3: 0x0000000109d0d490 libpmpi.12.dylib`MPIR_Barrier + 900 >>>>>>> frame #4: 0x000000010224d030 libmpi.12.dylib`MPI_Barrier + 684 >>>>>>> frame #5: 0x00000001045ea638 >>>>>>> libpetsc.3.17.dylib`PetscCommDuplicate(comm_in=-2080374782, >>>>>>> comm_out=0x000000010300bcb0, first_tag=0x000000010300bce4) at tagm.c >>>>>>> :235:5 >>>>>>> frame #6: 0x00000001045f2910 >>>>>>> libpetsc.3.17.dylib`PetscHeaderCreate_Private(h=0x000000010300bc70, >>>>>>> classid=1211227, class_name="PetscSF", descr="Star Forest", >>>>>>> mansec="PetscSF", comm=-2080374782, >>>>>>> destroy=(libpetsc.3.17.dylib`PetscSFDestroy at sf.c:224), >>>>>>> view=(libpetsc.3.17.dylib`PetscSFView at sf.c:841)) at inherit.c:62: >>>>>>> 3 >>>>>>> frame #7: 0x00000001049cf820 >>>>>>> libpetsc.3.17.dylib`PetscSFCreate(comm=-2080374782, >>>>>>> sf=0x000000016f911a50) >>>>>>> at sf.c:62:3 >>>>>>> frame #8: 0x0000000104cd3024 >>>>>>> libpetsc.3.17.dylib`MatZeroRowsMapLocal_Private(A=0x00000001170c1270, >>>>>>> N=1, >>>>>>> rows=0x000000016f912cb4, nr=0x000000016f911df8, >>>>>>> olrows=0x000000016f911e00) >>>>>>> at zerorows.c:36:5 >>>>>>> frame #9: 0x000000010504ea50 >>>>>>> libpetsc.3.17.dylib`MatZeroRows_MPIAIJ(A=0x00000001170c1270, N=1, >>>>>>> rows=0x000000016f912cb4, diag=1, x=0x0000000000000000, >>>>>>> b=0x0000000000000000) at mpiaij.c:768:3 >>>>>>> >>>>>>> -- What most experimenters take for granted before they begin their experiments is infinitely more interesting than any results to which their experiments lead. -- Norbert Wiener https://www.cse.buffalo.edu/~knepley/ <http://www.cse.buffalo.edu/~knepley/>