we can use -j 4 for make in CI

.github/workflows/burn_cell_metal_chem.yml

@@ -31,7 +31,7 @@ jobs:
       - name: Compile
         run: |
           cd unit_test/burn_cell_metal_chem
-          make -j 2
+          make -j 4
 
       - name: Run and compare outputs for different Z values, also including cosmic ray ionization
         run: |

.github/workflows/burn_cell_primordial_chem.yml

@@ -31,7 +31,7 @@ jobs:
       - name: Compile and run
         run: |
           cd unit_test/burn_cell_primordial_chem
-          make -j 2
+          make -j 4
           ./main1d.gnu.DEBUG.ex inputs_primordial_chem amrex.fpe_trap_{invalid,zero,overflow}=1 > test.out
 
       - name: Print backtrace

.github/workflows/c-linter.yml

@@ -26,7 +26,7 @@ jobs:
         uses: AMReX-Astro/cpp-linter-action@main
         with:
           build_path: 'unit_test/test_react'
-          make_options: '-j 2 USE_OMP=FALSE USE_MPI=FALSE USE_CUDA=FALSE DEBUG=TRUE'
+          make_options: '-j 4 USE_OMP=FALSE USE_MPI=FALSE USE_CUDA=FALSE DEBUG=TRUE'
           ignore_files: 'amrex|util/gcem'
           header_filter: '(/conductivity/|/constants/|/EOS/|/integration/|/interfaces/|/networks/|/neutrinos/|/nse_solver/|/opacity/|/rates/|/screening/|/util/|^\./).*\.H$'
           config_file: ${GITHUB_WORKSPACE}/.clang-tidy

.github/workflows/castro-development.yml

@@ -47,7 +47,7 @@ jobs:
         export MICROPHYSICS_HOME=${PWD}
 
         cd Castro/Exec/science/flame_wave/
-        make -j2 CCACHE=ccache USE_MPI=FALSE
+        make -j 4 CCACHE=ccache USE_MPI=FALSE
 
         ccache -s
         du -hs ~/.cache/ccache
@@ -64,7 +64,7 @@ jobs:
         export MICROPHYSICS_HOME=${PWD}
 
         cd Castro/Exec/science/subchandra/
-        make -j2 CCACHE=ccache USE_MPI=FALSE
+        make -j 4 CCACHE=ccache USE_MPI=FALSE
 
         ccache -s
         du -hs ~/.cache/ccache

.github/workflows/castro.yml

@@ -51,7 +51,7 @@ jobs:
         export MICROPHYSICS_HOME=${PWD}
 
         cd Castro/Exec/science/flame_wave/
-        make -j2 CCACHE=ccache USE_MPI=FALSE
+        make -j 4 CCACHE=ccache USE_MPI=FALSE
 
         ccache -s
         du -hs ~/.cache/ccache
@@ -68,7 +68,7 @@ jobs:
         export MICROPHYSICS_HOME=${PWD}
 
         cd Castro/Exec/science/subchandra/
-        make -j2 CCACHE=ccache USE_MPI=FALSE
+        make -j 4 CCACHE=ccache USE_MPI=FALSE
 
         ccache -s
         du -hs ~/.cache/ccache

.github/workflows/cmake_build_cell_primordial_chem.yml

@@ -18,5 +18,5 @@ jobs:
         run: |
           mkdir build && cd build
           cmake .. -DBUILD_UNIT_TEST=true -DBUILD_AMReX=true
-          make -j2
+          make -j 4
           ctest --output-on-failure

.github/workflows/cuda.yml

@@ -32,17 +32,17 @@ jobs:
         run: |
           export PATH=/usr/local/nvidia/bin:/usr/local/cuda/bin:${PATH}
           cd unit_test/test_react
-          make NETWORK_DIR=aprox13 USE_CUDA=TRUE COMP=gnu USE_MPI=FALSE -j 2
+          make NETWORK_DIR=aprox13 USE_CUDA=TRUE COMP=gnu USE_MPI=FALSE -j 4
 
       - name: compile test_react (ignition_reaclib/URCA-simple)
         run: |
           export PATH=/usr/local/nvidia/bin:/usr/local/cuda/bin:${PATH}
           cd unit_test/test_react
           make realclean
-          make NETWORK_DIR=ignition_reaclib/URCA-simple USE_CUDA=TRUE COMP=gnu USE_MPI=FALSE -j 2
+          make NETWORK_DIR=ignition_reaclib/URCA-simple USE_CUDA=TRUE COMP=gnu USE_MPI=FALSE -j 4
 
       - name: compile test_nse_net (ase)
         run: |
           export PATH=/usr/local/nvidia/bin:/usr/local/cuda/bin:${PATH}
           cd unit_test/test_nse_net
-          make USE_CUDA=TRUE COMP=gnu USE_MPI=FALSE -j 2
+          make USE_CUDA=TRUE COMP=gnu USE_MPI=FALSE -j 4

.github/workflows/macos_build_cell_metal_chem.yml

@@ -17,5 +17,5 @@ jobs:
         run: |
           mkdir build && cd build
           cmake .. -DBUILD_UNIT_TEST_MC=true -DBUILD_AMReX=true
-          make -j2
+          make -j 4
           ctest --output-on-failure

.github/workflows/macos_build_cell_primordial_chem.yml

@@ -17,5 +17,5 @@ jobs:
         run: |
           mkdir build && cd build
           cmake .. -DBUILD_UNIT_TEST_PC=true -DBUILD_AMReX=true
-          make -j2
+          make -j 4
           ctest --output-on-failure

.github/workflows/test_neutrinos.yml

@@ -29,7 +29,7 @@ jobs:
       - name: Build the fextrema tool
         run: |
           cd external/amrex/Tools/Plotfile
-          make programs=fextrema -j 2
+          make programs=fextrema -j 4
 
       - name: Compile
         run: |

.github/workflows/test_rhs.yml

@@ -29,7 +29,7 @@ jobs:
       - name: Build the fextrema tool
         run: |
           cd external/amrex/Tools/Plotfile
-          make programs=fextrema -j 2
+          make programs=fextrema -j 4
 
       - name: Compile, test_rhs (VODE, ignition_simple)
         run: |