ci(release): share the dist build memory guard with Release Performance

.github/actions/dist-build-memory/action.yml

@@ -0,0 +1,48 @@
+name: Memory for a Linux dist build
+description: >-
+  A Linux build with the dist cargo profile compiles its largest single-unit crates at the same
+  time and can use more memory than the hosted runner has; the runner is then lost without a build
+  error. `start` adds host swap (which a manylinux container shares), limits cargo to three crates
+  at a time for the rest of the job, and samples used memory; `report` stops sampling and prints
+  the peak.
+inputs:
+  step:
+    description: "`start` before the dist build, `report` after it (run it with always())"
+    required: true
+runs:
+  using: composite
+  steps:
+    - name: Add swap and limit cargo jobs
+      if: inputs.step == 'start'
+      shell: bash
+      run: |
+        free -m
+        avail="$(df -BG --output=avail /mnt 2>/dev/null | tail -n 1 | tr -dc '0-9')"
+        swap_dir=/mnt
+        if [[ -z "${avail}" || "${avail}" -lt 24 ]]; then
+          swap_dir=""
+        fi
+        swapfile="${swap_dir}/sqlbuild-dist.swap"
+        sudo fallocate -l 16G "${swapfile}"
+        sudo chmod 600 "${swapfile}"
+        sudo mkswap "${swapfile}" > /dev/null
+        sudo swapon "${swapfile}"
+        free -m
+        # maturin-action passes CARGO_* variables into its manylinux container.
+        echo "CARGO_BUILD_JOBS=3" >> "${GITHUB_ENV}"
+        ( while :; do
+            free -m | awk '/^Mem:/ { ram = $3 } /^Swap:/ { swap = $3 } END { print ram, swap }'
+            sleep 5
+          done ) > "${RUNNER_TEMP}/dist-memory.log" 2>&1 &
+        echo $! > "${RUNNER_TEMP}/dist-memory.pid"
+    - name: Report memory use
+      if: inputs.step == 'report'
+      shell: bash
+      run: |
+        # Stop sampling, so later steps such as timing measurements run without it.
+        kill "$(cat "${RUNNER_TEMP}/dist-memory.pid")" 2>/dev/null || true
+        free -m
+        grep -E '^pswp(in|out) ' /proc/vmstat
+        awk '{ if ($1 > ram) ram = $1; if ($2 > swap) swap = $2; if ($1 + $2 > both) both = $1 + $2 }
+          END { printf "Peak used memory: RAM %d MiB, swap %d MiB, together %d MiB\n", ram, swap, both }' \
+          "${RUNNER_TEMP}/dist-memory.log" | tee -a "${GITHUB_STEP_SUMMARY}"

.github/workflows/build-distributions.yml

@@ -141,29 +141,12 @@ jobs:
         run: |
           npm ci
           npm run build
-      # In a Linux dist build the largest single-unit crates compile at the same time and can use
-      # more memory than the hosted runner has; the runner is then lost without a build error.
-      # Swap on the host, which the manylinux container shares, absorbs that peak, the builds below
-      # compile at most three crates at a time, and the sampled memory use is reported afterwards.
-      - name: Add swap for the Linux dist build
+      # A Linux dist build can need more memory than the hosted runner has; see the action.
+      - name: Add swap and limit cargo jobs for the Linux dist build
         if: inputs.prebuilt-run-id == '' && runner.os == 'Linux' && inputs.cargo-profile == 'dist'
-        run: |
-          free -m
-          avail="$(df -BG --output=avail /mnt 2>/dev/null | tail -n 1 | tr -dc '0-9')"
-          swap_dir=/mnt
-          if [[ -z "${avail}" || "${avail}" -lt 24 ]]; then
-            swap_dir=""
-          fi
-          swapfile="${swap_dir}/sqlbuild-dist.swap"
-          sudo fallocate -l 16G "${swapfile}"
-          sudo chmod 600 "${swapfile}"
-          sudo mkswap "${swapfile}" > /dev/null
-          sudo swapon "${swapfile}"
-          free -m
-          ( while :; do
-              free -m | awk '/^Mem:/ { ram = $3 } /^Swap:/ { swap = $3 } END { print ram, swap }'
-              sleep 5
-            done ) > "${RUNNER_TEMP}/dist-memory.log" 2>&1 &
+        uses: ./.github/actions/dist-build-memory
+        with:
+          step: start
       # maturin-action downloads maturin from GitHub releases, which can fail on its own. Each
       # build retries once; macOS and Windows then fall back to the same maturin from PyPI. Linux
       # builds need the action's manylinux container, so they have no fallback.
@@ -177,7 +160,6 @@ jobs:
           args: >-
             --profile ${{ inputs.cargo-profile }} --out dist --features extension-module
             ${{ matrix.platform.name == 'linux-x86_64' && '--timings' || '' }}
-            ${{ runner.os == 'Linux' && inputs.cargo-profile == 'dist' && '--jobs 3' || '' }}
           target: ${{ matrix.platform.target }}
           manylinux: auto
       - id: extension-retry
@@ -191,7 +173,6 @@ jobs:
           args: >-
             --profile ${{ inputs.cargo-profile }} --out dist --features extension-module
             ${{ matrix.platform.name == 'linux-x86_64' && '--timings' || '' }}
-            ${{ runner.os == 'Linux' && inputs.cargo-profile == 'dist' && '--jobs 3' || '' }}
           target: ${{ matrix.platform.target }}
           manylinux: auto
       - name: Build the extension with maturin from PyPI
@@ -222,7 +203,6 @@ jobs:
           args: >-
             --profile ${{ inputs.cargo-profile }} --out dist --manifest-path crates/sqlbuild-cli/Cargo.toml --features ui
             ${{ matrix.platform.name == 'linux-x86_64' && '--timings' || '' }}
-            ${{ runner.os == 'Linux' && inputs.cargo-profile == 'dist' && '--jobs 3' || '' }}
           target: ${{ matrix.platform.target }}
           manylinux: auto
       - id: cli-retry
@@ -240,7 +220,6 @@ jobs:
           args: >-
             --profile ${{ inputs.cargo-profile }} --out dist --manifest-path crates/sqlbuild-cli/Cargo.toml --features ui
             ${{ matrix.platform.name == 'linux-x86_64' && '--timings' || '' }}
-            ${{ runner.os == 'Linux' && inputs.cargo-profile == 'dist' && '--jobs 3' || '' }}
           target: ${{ matrix.platform.target }}
           manylinux: auto
       - name: Build sqb with maturin from PyPI
@@ -261,12 +240,9 @@ jobs:
         if: >-
           always() && inputs.prebuilt-run-id == '' && runner.os == 'Linux'
           && inputs.cargo-profile == 'dist'
-        run: |
-          free -m
-          grep -E '^pswp(in|out) ' /proc/vmstat
-          awk '{ if ($1 > ram) ram = $1; if ($2 > swap) swap = $2; if ($1 + $2 > both) both = $1 + $2 }
-            END { printf "Peak used memory: RAM %d MiB, swap %d MiB, together %d MiB\n", ram, swap, both }' \
-            "${RUNNER_TEMP}/dist-memory.log" | tee -a "${GITHUB_STEP_SUMMARY}"
+        uses: ./.github/actions/dist-build-memory
+        with:
+          step: report
       - name: Upload the cargo build timing reports
         if: inputs.prebuilt-run-id == '' && matrix.platform.name == 'linux-x86_64'
         uses: actions/upload-artifact@v4

.github/workflows/release-performance.yml

@@ -18,6 +18,7 @@ on:
   pull_request:
     paths:
       - .github/workflows/release-performance.yml
+      - .github/actions/dist-build-memory/**
       - scripts/compare_release_performance.py
       - scripts/release_performance/**
       - scripts/compile_performance_ratio/_helpers/edit.py
@@ -67,12 +68,22 @@ jobs:
       - name: Install dependencies
         run: uv sync --locked --all-groups --all-extras
       # The candidate uses the released wheels' cargo profile, so both sides of the comparison match.
+      # That build can need more memory than the hosted runner has; see the action.
+      - name: Add swap and limit cargo jobs for the candidate build
+        uses: ./.github/actions/dist-build-memory
+        with:
+          step: start
       - name: Build candidate wheel
         env:
           MATURIN_PEP517_ARGS: --profile dist
         run: |
           uv build --wheel --out-dir "${RUNNER_TEMP}/candidate"
           uv build --wheel crates/sqlbuild-cli --out-dir "${RUNNER_TEMP}/candidate"
+      - name: Report memory use of the candidate build
+        if: always()
+        uses: ./.github/actions/dist-build-memory
+        with:
+          step: report
       # A release tag created while the candidate built names the baseline's benchmark generator.
       - name: Fetch release tags
         run: git fetch --tags --force --quiet origin