Issue with benchmark 5.4.12 in manual about parameter "Linear solver A block tolerance"

Today I ran benchmark 5.4.12. With the origin file there is an error:

The iterative (top left) solver in BlockSchurPreconditioner::vmult did not converge to a tolerance of 0.0099956613402214668. It reported the following error

So I changed “Linear solver A block tolerance” from “1e-2” to “1e-1”, and the error disappeared.

But why is it an issue on my machine? And is it a good thing to change this parameter?

Dear lhy11009,

Sorry to hear you had problems running one of the benchmarks. Please post more information about your problem. Ideally post your whole output/log.txt file (if it is small), or at least the header lines (ASPECT version, deal.II version) and the last timesteps or so. Also which benchmark did you run (which input file)? Without the version information I am not sure which benchmark you are running as the manual changes between versions. Is it the Stokes law benchmark?

We usually make sure all benchmarks are running for every release (and have lots of smaller tests between releases), so either you are using a combination of ASPECT and deal.II (or the underlying libraries) that we have not tested, or something changed in the recent development version without us noticing.

For reference I attach the results of the Stokes benchmark (cookbooks/stokes.prm) on my laptop so you can compare:

-----------------------------------------------------------------------------
-- This is ASPECT, the Advanced Solver for Problems in Earth's ConvecTion.
--     . version 2.2.0-pre (master, f0c62fc99)
--     . using deal.II 9.2.0-pre (master, 24fc4f42ed)
--     .       with 32 bit indices and vectorization level 2 (256 bits)
--     . using Trilinos 12.10.1
--     . using p4est 2.0.0
--     . running in DEBUG mode
--     . running with 6 MPI processes
-----------------------------------------------------------------------------


-----------------------------------------------------------------------------
The output directory <output-stokes/> provided in the input file appears not to exist.
ASPECT will create it for you.
-----------------------------------------------------------------------------


-----------------------------------------------------------------------------
-- For information on how to cite ASPECT, see:
--   https://aspect.geodynamics.org/citing.html?ver=2.2.0-pre&sha=f0c62fc99&src=code
-----------------------------------------------------------------------------
Number of active cells: 4,096 (on 5 levels)
Number of degrees of freedom: 184,598 (107,811+4,913+35,937+35,937)

*** Timestep 0:  t=0 seconds
   Skipping temperature solve because RHS is zero.
   Solving C_1 system ... 0 iterations.
   Rebuilding Stokes preconditioner...
   Solving Stokes system... 36+0 iterations.

Number of active cells: 1,128 (on 5 levels)
Number of degrees of freedom: 57,444 (33,519+1,579+11,173+11,173)

*** Timestep 0:  t=0 seconds
   Skipping temperature solve because RHS is zero.
   Solving C_1 system ... 0 iterations.
   Rebuilding Stokes preconditioner...
   Solving Stokes system... 30+0 iterations.

Number of active cells: 1,100 (on 6 levels)
Number of degrees of freedom: 57,282 (33,417+1,587+11,139+11,139)

*** Timestep 0:  t=0 seconds
   Skipping temperature solve because RHS is zero.
   Solving C_1 system ... 0 iterations.
   Rebuilding Stokes preconditioner...
   Solving Stokes system... 31+0 iterations.

Number of active cells: 1,156 (on 6 levels)
Number of degrees of freedom: 61,017 (35,595+1,692+11,865+11,865)

*** Timestep 0:  t=0 seconds
   Skipping temperature solve because RHS is zero.
   Solving C_1 system ... 0 iterations.
   Rebuilding Stokes preconditioner...
   Solving Stokes system... 31+0 iterations.

Number of active cells: 1,261 (on 6 levels)
Number of degrees of freedom: 66,191 (38,619+1,826+12,873+12,873)

*** Timestep 0:  t=0 seconds
   Skipping temperature solve because RHS is zero.
   Solving C_1 system ... 0 iterations.
   Rebuilding Stokes preconditioner...
   Solving Stokes system... 31+0 iterations.

   Postprocessing:
     Writing graphical output: output-stokes/solution/solution-00000
     RMS, max velocity:        8.57e-11 m/s, 1.18e-09 m/s

Termination requested by criterion: end time