Dear PETSc, On Tuesday I sent a small reproducer program that shows a problem with the Fortran version of DMCompositeGetGlobalISs, with the valgrind stack trace below.
Not having yet received a reply, I’m just wondering if perhaps my email slipped through the cracks. Would appreciate some guidance here so we can continue our code upgrade from petsc 3.19 to 3.23. Thanks, Randy > On Jun 18, 2025, at 2:44 PM, Randall Mackie <rlmackie...@gmail.com> wrote: > > Follow up: running with valgrind shows the following issues….is this a bug in > PETSc? > > ==5216== Use of uninitialised value of size 8 > ==5216== at 0x49ED69C: f90array1dcreatefortranaddr_ (f90_fwrap.F90:52) > ==5216== by 0x4D7EA94: F90Array1dCreate (f90_cwrap.c:140) > ==5216== by 0x6B7295A: dmcompositegetglobaliss_ (zfddaf.c:70) > ==5216== by 0x1095C8: MAIN__ (test.F90:35) > ==5216== by 0x1096AC: main (test.F90:4) > ==5216== Uninitialised value was created by a stack allocation > ==5216== at 0x109219: MAIN__ (test.F90:1) > ==5216== > ==5216== Invalid write of size 8 > ==5216== at 0x49ED69C: f90array1dcreatefortranaddr_ (f90_fwrap.F90:52) > ==5216== by 0x4D7EA94: F90Array1dCreate (f90_cwrap.c:140) > ==5216== by 0x6B7295A: dmcompositegetglobaliss_ (zfddaf.c:70) > ==5216== by 0x1095C8: MAIN__ (test.F90:35) > ==5216== by 0x1096AC: main (test.F90:4) > ==5216== Address 0x20 is not stack'd, malloc'd or (recently) free'd > ==5216== > > > Thanks, Randyt > > > >> On Jun 17, 2025, at 3:39 PM, Randall Mackie <rlmackie...@gmail.com> wrote: >> >> Dear Petsc users - >> >> I am trying to upgrade my code to petsc-3.23 (from 3.19), and I seem to have >> run into a problem with DMCompositeGetGlobalISs. >> >> The example program listed on the man page for DMCompositeGetGlobalISs, >> https://urldefense.us/v3/__https://petsc.org/release/src/snes/tutorials/ex73f90t.F90.html__;!!G_uCfscf7eWS!Z2gkoRqGs_off3mdHshweKBv_JQzRrYyYBMN7hIRUHEZIypl2PnZFuidgVHE4iuK9FNlN1y4PtlNyahPNhcFiO1S2w$ >> , seems to indicate that a call to DMCompositeGetGlobalISs does not need to >> allocate the IS pointer and you just pass it directly to >> DMCompositeGetGlobalISs. >> >> If I compile and run the simple attached test program (say on 2 processes), >> I get the following error: >> >> [0]PETSC ERROR: >> ------------------------------------------------------------------------ >> [0]PETSC ERROR: Caught signal number 11 SEGV: Segmentation Violation, >> probably memory access out of range >> [0]PETSC ERROR: Try option -start_in_debugger or -on_error_attach_debugger >> [0]PETSC ERROR: or see >> https://urldefense.us/v3/__https://petsc.org/release/faq/*valgrind__;Iw!!G_uCfscf7eWS!Z2gkoRqGs_off3mdHshweKBv_JQzRrYyYBMN7hIRUHEZIypl2PnZFuidgVHE4iuK9FNlN1y4PtlNyahPNhdiZKy11Q$ >> and >> https://urldefense.us/v3/__https://petsc.org/release/faq/__;!!G_uCfscf7eWS!Z2gkoRqGs_off3mdHshweKBv_JQzRrYyYBMN7hIRUHEZIypl2PnZFuidgVHE4iuK9FNlN1y4PtlNyahPNhdzXsvxLQ$ >> >> [0]PETSC ERROR: --------------------- Stack Frames >> ------------------------------------ >> [0]PETSC ERROR: The line numbers in the error traceback may not be exact. >> [0]PETSC ERROR: #1 F90Array1dCreate() at >> /home/rmackie/PETSc/petsc-3.23.3/src/sys/ftn-custom/f90_cwrap.c:123 >> application called MPI_Abort(MPI_COMM_WORLD, 59) - process 0 >> >> >> If I uncomment the line to allocate the pointer, I get a very long traceback >> with lots of error messages. >> >> What is the correct way to use DMCompositeGetGlobalISs in Fortran? With or >> without the pointer allocation, and what is the right way to do this without >> the errors it seems to generate? >> >> Thanks, >> >> Randy Mackie >> >> <test.F90> >
