ci: Use nproc-2 to set parallelism for builds and tests (#5939)

This change reduces the number of cores used to build and test, as using all cores may be contributing to occasional build and test failures.

Co-authored-by: Bart Thomee <11445373+bthomee@users.noreply.github.com>

.github/workflows/publish-docs.yml

@@ -23,6 +23,7 @@ defaults:
 
 env:
   BUILD_DIR: .build
+  NPROC_SUBTRACT: 2
 
 jobs:
   publish:
@@ -33,6 +34,13 @@ jobs:
     steps:
       - name: Checkout repository
         uses: actions/checkout@08eba0b27e820071cde6df949e0beb9ba4906955 # v4.3.0
+
+      - name: Get number of processors
+        uses: XRPLF/actions/.github/actions/get-nproc@046b1620f6bfd6cd0985dc82c3df02786801fe0a
+        id: nproc
+        with:
+          subtract: ${{ env.NPROC_SUBTRACT }}
+
       - name: Check configuration
         run: |
           echo 'Checking path.'
@@ -46,12 +54,16 @@ jobs:
 
           echo 'Checking Doxygen version.'
           doxygen --version
+
       - name: Build documentation
+        env:
+          BUILD_NPROC: ${{ steps.nproc.outputs.nproc }}
         run: |
           mkdir -p "${BUILD_DIR}"
           cd "${BUILD_DIR}"
           cmake -Donly_docs=ON ..
-          cmake --build . --target docs --parallel $(nproc)
+          cmake --build . --target docs --parallel ${BUILD_NPROC}
+
       - name: Publish documentation
         if: ${{ github.ref_type == 'branch' && github.ref_name == github.event.repository.default_branch }}
         uses: peaceiris/actions-gh-pages@4f9cc6602d3f66b9c108549d475ec49e8ef4d45e # v4.0.0

.github/workflows/reusable-build-test-config.yml

@@ -39,6 +39,12 @@ on:
         required: true
         type: string
 
+      nproc_subtract:
+        description: "The number of processors to subtract when calculating parallelism."
+        required: false
+        type: number
+        default: 2
+
     secrets:
       CODECOV_TOKEN:
         description: "The Codecov token to use for uploading coverage reports."
@@ -55,6 +61,7 @@ jobs:
       runs_on: ${{ inputs.runs_on }}
       image: ${{ inputs.image }}
       config_name: ${{ inputs.config_name }}
+      nproc_subtract: ${{ inputs.nproc_subtract }}
     secrets:
       CODECOV_TOKEN: ${{ secrets.CODECOV_TOKEN }}
 
@@ -67,3 +74,4 @@ jobs:
       runs_on: ${{ inputs.runs_on }}
       image: ${{ inputs.image }}
       config_name: ${{ inputs.config_name }}
+      nproc_subtract: ${{ inputs.nproc_subtract }}

.github/workflows/reusable-build.yml

@@ -34,6 +34,11 @@ on:
         required: true
         type: string
 
+      nproc_subtract:
+        description: "The number of processors to subtract when calculating parallelism."
+        required: true
+        type: number
+
     secrets:
       CODECOV_TOKEN:
         description: "The Codecov token to use for uploading coverage reports."
@@ -65,6 +70,12 @@ jobs:
       - name: Print build environment
         uses: ./.github/actions/print-env
 
+      - name: Get number of processors
+        uses: XRPLF/actions/.github/actions/get-nproc@046b1620f6bfd6cd0985dc82c3df02786801fe0a
+        id: nproc
+        with:
+          subtract: ${{ inputs.nproc_subtract }}
+
       - name: Setup Conan
         uses: ./.github/actions/setup-conan
 
@@ -72,7 +83,11 @@ jobs:
         uses: ./.github/actions/build-deps
         with:
           build_dir: ${{ inputs.build_dir }}
+          build_nproc: ${{ steps.nproc.outputs.nproc }}
           build_type: ${{ inputs.build_type }}
+          # Set the verbosity to "quiet" for Windows to avoid an excessive
+          # amount of logs. For other OSes, the "verbose" logs are more useful.
+          log_verbosity: ${{ runner.os == 'Windows' && 'quiet' || 'verbose' }}
 
       - name: Configure CMake
         shell: bash
@@ -92,13 +107,14 @@ jobs:
         shell: bash
         working-directory: ${{ inputs.build_dir }}
         env:
+          BUILD_NPROC: ${{ steps.nproc.outputs.nproc }}
           BUILD_TYPE: ${{ inputs.build_type }}
           CMAKE_TARGET: ${{ inputs.cmake_target }}
         run: |
           cmake \
             --build . \
             --config "${BUILD_TYPE}" \
-            --parallel $(nproc) \
+            --parallel ${BUILD_NPROC} \
             --target "${CMAKE_TARGET}"
 
       - name: Put built binaries in one location

.github/workflows/reusable-test.yml

@@ -26,6 +26,11 @@ on:
         required: true
         type: string
 
+      nproc_subtract:
+        description: "The number of processors to subtract when calculating parallelism."
+        required: true
+        type: number
+
 jobs:
   test:
     name: Test ${{ inputs.config_name }}
@@ -37,6 +42,12 @@ jobs:
         if: ${{ runner.os == 'macOS' }}
         uses: XRPLF/actions/.github/actions/cleanup-workspace@3f044c7478548e3c32ff68980eeb36ece02b364e
 
+      - name: Get number of processors
+        uses: XRPLF/actions/.github/actions/get-nproc@046b1620f6bfd6cd0985dc82c3df02786801fe0a
+        id: nproc
+        with:
+          subtract: ${{ inputs.nproc_subtract }}
+
       - name: Download rippled artifact
         uses: actions/download-artifact@d3f86a106a0bac45b974a628896c90dbdf5c8093 # v4.3.0
         with:
@@ -69,8 +80,10 @@ jobs:
       - name: Run the embedded tests
         if: ${{ inputs.run_tests }}
         shell: bash
+        env:
+          BUILD_NPROC: ${{ steps.nproc.outputs.nproc }}
         run: |
-          ./rippled --unittest --unittest-jobs $(nproc)
+          ./rippled --unittest --unittest-jobs ${BUILD_NPROC}
 
       - name: Run the separate tests
         if: ${{ inputs.run_tests }}

.github/workflows/upload-conan-deps.yml

@@ -34,6 +34,7 @@ on:
 env:
   CONAN_REMOTE_NAME: xrplf
   CONAN_REMOTE_URL: https://conan.ripplex.io
+  NPROC_SUBTRACT: 2
 
 concurrency:
   group: ${{ github.workflow }}-${{ github.ref }}
@@ -61,12 +62,23 @@ jobs:
         if: ${{ runner.os == 'macOS' }}
         uses: XRPLF/actions/.github/actions/cleanup-workspace@3f044c7478548e3c32ff68980eeb36ece02b364e
 
-      - uses: actions/checkout@08eba0b27e820071cde6df949e0beb9ba4906955 # v4.3.0
+      - name: Checkout repository
+        uses: actions/checkout@08eba0b27e820071cde6df949e0beb9ba4906955 # v4.3.0
+
       - name: Prepare runner
         uses: XRPLF/actions/.github/actions/prepare-runner@638e0dc11ea230f91bd26622fb542116bb5254d5
         with:
           disable_ccache: false
 
+      - name: Print build environment
+        uses: ./.github/actions/print-env
+
+      - name: Get number of processors
+        uses: XRPLF/actions/.github/actions/get-nproc@046b1620f6bfd6cd0985dc82c3df02786801fe0a
+        id: nproc
+        with:
+          subtract: ${{ env.NPROC_SUBTRACT }}
+
       - name: Setup Conan
         uses: ./.github/actions/setup-conan
         with:
@@ -77,11 +89,12 @@ jobs:
         uses: ./.github/actions/build-deps
         with:
           build_dir: .build
+          build_nproc: ${{ steps.nproc.outputs.nproc }}
           build_type: ${{ matrix.build_type }}
           force_build: ${{ github.event_name == 'schedule' || github.event.inputs.force_source_build == 'true' }}
-          # The verbosity is set to "quiet" for Windows to avoid an excessive amount of logs, while it
-          # is set to "verbose" otherwise to provide more information during the build process.
-          verbosity: ${{ runner.os == 'Windows' && 'quiet' || 'verbose' }}
+          # Set the verbosity to "quiet" for Windows to avoid an excessive
+          # amount of logs. For other OSes, the "verbose" logs are more useful.
+          log_verbosity: ${{ runner.os == 'Windows' && 'quiet' || 'verbose' }}
 
       - name: Log into Conan remote
         if: ${{ github.repository_owner == 'XRPLF' && (github.event_name == 'push' || github.event_name == 'workflow_dispatch') }}