feat: Improve linear solvers testing

.github/workflows/build_and_test.yml

@@ -395,7 +395,6 @@ jobs:
             echo "No new baseline archive was generated."
           fi
         fi
-
         if [[ "${{ inputs.UPLOAD_TO_GCP }}" == "true" && -n "${{ inputs.GCP_BUCKET }}" ]]; then
           if [[ "${{ inputs.BUILD_TYPE }}" = "integrated_tests" || ${EXIT_STATUS} -eq 0 ]]; then
             CLOUDSDK_PYTHON=python3 gcloud config set storage/parallel_composite_upload_enabled True

BASELINE_NOTES.md

@@ -14,25 +14,40 @@ Stop dumping linear systems from ATS decks (`writeLinearSystem` no longer set).
 PR #4088 (2026-07-27) <https://storage.googleapis.com/geosx/integratedTests/baseline_integratedTests-pr4088-17188-4247846.tar.gz>
 Fluid reset after convergence failure
 
+PR #3972 (2026-08-DD) <https://storage.googleapis.com/geosx/integratedTests/baseline_integratedTests-pr4108-17194-fec5349.tar.gz>
+=====================
+Add MGR tests to ATS
+
 PR #3972 (2026-07-28) <https://storage.googleapis.com/geosx/integratedTests/baseline_integratedTests-pr3972-17154-316e6d8.tar.gz>
-Well model refactor .  Integrated test update due to schema changes 
+=====================
+Well model refactor .  Integrated test update due to schema changes
+
+PR #4088 (2026-07-27) <https://storage.googleapis.com/geosx/integratedTests/baseline_integratedTests-pr4088-17188-4247846.tar.gz>
+=====================
+Fluid reset after convergence failure
 
 PR #3836 (2026-05-20) <https://storage.googleapis.com/geosx/integratedTests/baseline_integratedTests-pr3836-17046-2e89f64.tar.gz>
+=====================
 Added statistics `Group` objects for each statistics `Task` instance
 
 PR #4040 (2026-06-16) <https://storage.googleapis.com/geosx/integratedTests/baseline_integratedTests-pr4040-16993-1393f80.tar.gz>
+=====================
 Move relperm driver to use new constitutive driver framework
 
 PR #3705 (2026-06-12) <https://storage.googleapis.com/geosx/integratedTests/baseline_integratedTests-pr3705-16862-2b262bf.tar.gz>
+=====================
 Implement compositional enthalpy model
 
 PR #4074 (2026-06-10) <https://storage.googleapis.com/geosx/integratedTests/baseline_integratedTests-pr4074-16937-bf66240.tar.gz>
+=====================
 Change triaxial driver to use restart for checks
 
 PR #4067 (2026-06-10) <https://storage.googleapis.com/geosx/integratedTests/baseline_integratedTests-pr4067-16928-3038f6b.tar.gz>
+=====================
 Add Coulomb friction/cohesion input from vtk mesh
 
 PR #4068 (2026-06-09) <https://storage.googleapis.com/geosx/integratedTests/baseline_integratedTests-pr4068-16828-c74157c.tar.gz>
+=====================
 Add MPI runs for smoke tests with surfaceGenerator
 
 PR #4062 (2026-05-26) <https://storage.googleapis.com/geosx/integratedTests/baseline_integratedTests-pr4062-16784-6d8782e.tar.gz>

inputFiles/compositionalMultiphaseFlow/compositionalMultiphaseFlow.ats

@@ -77,6 +77,14 @@ decks = [
         restart_step=28,
         check_step=38,
         restartcheck_params=RestartcheckParameters(**restartcheck_params)),
+    TestDeck(
+        name="deadoil_3ph_staircase_3d_iterative",
+        description=
+        "hypre MGR variant (exercises the hypredrive path when available)",
+        partitions=((1, 1, 1), (2, 2, 2)),
+        restart_step=28,
+        check_step=38,
+        restartcheck_params=RestartcheckParameters(atol=1e-6, rtol=1e-5)),
     TestDeck(
         name="deadoil_3ph_staircase_hybrid_3d",
         description=
@@ -85,6 +93,14 @@ decks = [
         restart_step=28,
         check_step=38,
         restartcheck_params=RestartcheckParameters(**restartcheck_params)),
+    TestDeck(
+        name="deadoil_3ph_staircase_hybrid_3d_iterative",
+        description=
+        "hypre MGR variant (exercises the hypredrive path when available)",
+        partitions=((1, 1, 1), (2, 2, 2)),
+        restart_step=28,
+        check_step=38,
+        restartcheck_params=RestartcheckParameters(atol=1e-6, rtol=1e-5)),
     TestDeck(
         name="deadoil_3ph_staircase_obl_3d",
         description=
@@ -93,6 +109,14 @@ decks = [
         restart_step=28,
         check_step=38,
         restartcheck_params=RestartcheckParameters(**restartcheck_params)),
+    TestDeck(
+        name="deadoil_3ph_staircase_obl_3d_iterative",
+        description=
+        "hypre MGR variant (exercises the hypredrive path when available)",
+        partitions=((1, 1, 1), (2, 2, 2)),
+        restart_step=28,
+        check_step=38,
+        restartcheck_params=RestartcheckParameters(atol=1e-6, rtol=1e-5)),
     TestDeck(
         name="deadoil_2ph_staircase_gravity_segregation_3d",
         description=