[petsc-users] Bug in VecNorm, 3.20.3

[Junchao Zhang]

Do you have an example to reproduce it?

--Junchao Zhang


On Tue, Jan 23, 2024 at 10:49 AM <michael at paraffinalia.co.uk> wrote:

> Hello,
>
> I have used the GMRES solver in PETSc successfully up to now, but on
> installing the most recent release, 3.20.3, the solver fails by exiting
> early. Output from the code is:
>
> lt-nbi-solve-laplace: starting PETSc solver [23.0537]
>    0 KSP Residual norm < 1.e-11
> Linear solve converged due to CONVERGED_ATOL iterations 0
> lt-nbi-solve-laplace: 0 iterations [23.0542] (22.9678)
>
> and tracing execution shows the norm returned by VecNorm to be 0.
>
> If I modify the function by commenting out line 217 of
>
>    src/vec/vec/interface/rvector.c
>
>    /* if (flg) PetscFunctionReturn(PETSC_SUCCESS); */
>
> the code executes correctly:
>
> lt-nbi-solve-laplace: starting PETSc solver [22.9392]
>    0 KSP Residual norm 1.10836
>    1 KSP Residual norm 0.0778301
>    2 KSP Residual norm 0.0125121
>    3 KSP Residual norm 0.00165836
>    4 KSP Residual norm 0.000164066
>    5 KSP Residual norm 2.12824e-05
>    6 KSP Residual norm 4.50696e-06
>    7 KSP Residual norm 5.85082e-07
> Linear solve converged due to CONVERGED_RTOL iterations 7
>
> My compile options are:
>
>   PETSC_ARCH=linux-gnu-real ./configure --with-mpi=0
> --with-scalar-type=real --with-threadsafety --with-debugging=0
> --with-log=0 --with-openmp
>
> uname -a returns:
>
> 5.15.80 #1 SMP PREEMPT Sun Nov 27 13:28:05 CST 2022 x86_64 Intel(R)
> Core(TM) i5-6200U CPU @ 2.30GHz GenuineIntel GNU/Linux
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.mcs.anl.gov/pipermail/petsc-users/attachments/20240123/e3ee7e46/attachment.html>