Reduce default --memory to 32Mi, set examples to measured minimums (#77)

danbugs · web-flow · commit 20ccc2ddb016 · 2026-05-21T15:48:22.000-07:00
* reduce default memory from 512Mi to 64Mi

every example already specifies its own --memory value in its Justfile,
so nothing depends on the CLI default. 64Mi comfortably covers the
lightweight examples (helloworld-c needs 4Mi, rust/go/dotnet/shell need
16Mi) while heavier workloads (python 512Mi, powershell 1Gi) continue
to set their own.

Signed-off-by: danbugs &lt;danilochiarlone@gmail.com&gt;

* set example memory to measured minimums, derive CI values from Justfiles

binary-searched the minimum --memory each example needs to produce its
expected output:

  helloworld-c: 2Mi    rust: 16Mi         go: 16Mi
  shell: 16Mi          dotnet: 16Mi       dotnet-nativeaot: 8Mi
  hostfs-posix-c: 2Mi  hostfs-posix-py: 512Mi  python: 512Mi
  python-tools: 512Mi  nodejs: 512Mi      powershell: 1Gi
  networking-py: 32Mi  python-agent: 1Gi

update each example's Justfile to use its measured minimum, and have CI
read the memory value from the Justfile instead of hardcoding it in the
workflow matrix. this makes the Justfile the single source of truth.

also fixes two under-provisioned examples that were silently relying on
headroom: hostfs-posix-py (was 96Mi, needs 512Mi) and python-tools
(was 96Mi, needs 512Mi).

lower the CLI default from 512Mi to 32Mi — covers every lightweight
example with headroom while giving an honest signal that heavy runtimes
(python, nodejs, powershell) need explicit --memory.

Signed-off-by: danbugs &lt;danilochiarlone@gmail.com&gt;

---------

Signed-off-by: danbugs &lt;danilochiarlone@gmail.com&gt;
diff --git a/.github/workflows/test-examples.yml b/.github/workflows/test-examples.yml
@@ -153,6 +153,9 @@ jobs:
   # Full matrix — every example actually runs and its expected output is
   # greped from the guest console. This is the real regression gate;
   # build-example above only catches link-time errors.
+  #
+  # Memory values are read from each example's Justfile at runtime
+  # (the `memory` variable), so the matrix only carries args/expect.
   runtime-test:
     runs-on: ubuntu-latest
     needs: build-example
@@ -165,76 +168,59 @@ jobs:
       matrix:
         include:
           - example: helloworld-c
-            memory: "4Mi"
             args: ""
             expect: "Hello from C on Hyperlight"
           - example: rust
-            memory: "16Mi"
             args: ""
             expect: "Hello from Rust on Hyperlight"
           - example: go
-            memory: "96Mi"
             args: ""
             expect: "Hello from Go on Hyperlight"
           - example: shell
-            memory: "16Mi"
             args: "-- /demo.sh"
             expect: "Hello from Shell on Hyperlight"
           - example: python
-            memory: "512Mi"
             args: "-- /hello.py"
             expect: "Hello from Python on Hyperlight"
           - example: python-tools
-            memory: "1Gi"
             args: "--enable-tools -- /test_tools.py"
             expect: "Tool returned"
           - example: nodejs
-            memory: "512Mi"
             args: "-- /app/hello.js"
             expect: "Hello from Node.js on Hyperlight"
           - example: dotnet
-            memory: "512Mi"
             args: ""
             expect: "Hello, World! From .NET on Hyperlight"
           - example: dotnet-nativeaot
-            memory: "512Mi"
             args: ""
             expect: "Hello, World! From .NET NativeAOT on Hyperlight"
           - example: hostfs-posix-c
-            memory: "16Mi"
             args: ""
             expect: "done\\."
             needs_mount: true
           - example: hostfs-posix-py
-            memory: "512Mi"
             args: "-- /hostfs_demo.py"
             expect: "done\\."
             needs_mount: true
           - example: multifn-c
-            memory: "4Mi"
             args: ""
             expect: "RUN: world"
             driver: multifn-test
           - example: python-agent
-            memory: "1Gi"
             args: "-- /agent.py"
             expect: "done\\."
             needs_mount: true
           - example: python-agent-driver
-            memory: "2Gi"
             args: ""
             expect: "hello from driver"
             driver: pydriver-run
           - example: powershell
-            memory: "1Gi"
             args: "-- -NoProfile -File /scripts/hello.ps1"
             expect: "Hello, World! From PowerShell on Hyperlight"
           - example: networking-py
-            memory: "512Mi"
             args: "--net -- /urllib_get.py"
             expect: "SUCCESS: urllib GET worked!"
           - example: networking-py
-            memory: "512Mi"
             args: "--port 8080 -- /echo_server_test.py"
             expect: "SUCCESS: bind\\+listen on port 8080 allowed"
     steps:
@@ -340,6 +326,11 @@ jobs:
             ls -la .unikraft/build/ *.cpio 2>&1 | head -40 || true
             exit 1
           fi
+          # Read memory from the example's Justfile (single source of truth).
+          memory=$(grep '^memory' Justfile | sed 's/memory.*:= *"//' | sed 's/".*//')
+          if [ -z "$memory" ]; then
+            echo "::notice::No memory variable in Justfile, using binary default"
+          fi
           expect='${{ matrix.expect }}'
           mount_args=""
           if [ "${{ matrix.needs_mount }}" = "true" ]; then
@@ -355,7 +346,11 @@ jobs:
               cmd=(timeout 120 /home/runner/work/hyperlight-unikraft/hyperlight-unikraft/host/target/release/pydriver-run "$kernel" "$cpio" /tmp/tiny.py)
               ;;
             *)
-              cmd=(timeout 120 hyperlight-unikraft -q -m "${{ matrix.memory }}" "$kernel" --initrd "$cpio" $mount_args ${{ matrix.args }})
+              mem_args=""
+              if [ -n "$memory" ]; then
+                mem_args="-m $memory"
+              fi
+              cmd=(timeout 120 hyperlight-unikraft -q $mem_args "$kernel" --initrd "$cpio" $mount_args ${{ matrix.args }})
               ;;
           esac
           set +e
@@ -490,6 +485,8 @@ jobs:
   # The only difference is we can't build the images on Windows (no
   # kraft-hyperlight + no Linux docker), so we download them from the
   # package-images-for-windows job.
+  #
+  # Memory values are read from each example's Justfile at runtime.
   runtime-test-windows:
     runs-on: windows-latest
     needs: package-images-for-windows
@@ -502,76 +499,59 @@ jobs:
       matrix:
         include:
           - example: helloworld-c
-            memory: "4Mi"
             args: ""
             expect: "Hello from C on Hyperlight"
           - example: rust
-            memory: "16Mi"
             args: ""
             expect: "Hello from Rust on Hyperlight"
           - example: go
-            memory: "96Mi"
             args: ""
             expect: "Hello from Go on Hyperlight"
           - example: shell
-            memory: "16Mi"
             args: "-- /demo.sh"
             expect: "Hello from Shell on Hyperlight"
           - example: python
-            memory: "512Mi"
             args: "-- /hello.py"
             expect: "Hello from Python on Hyperlight"
           - example: python-tools
-            memory: "1Gi"
             args: "--enable-tools -- /test_tools.py"
             expect: "Tool returned"
           - example: nodejs
-            memory: "512Mi"
             args: "-- /app/hello.js"
             expect: "Hello from Node.js on Hyperlight"
           - example: dotnet
-            memory: "512Mi"
             args: ""
             expect: "Hello, World! From .NET on Hyperlight"
           - example: dotnet-nativeaot
-            memory: "512Mi"
             args: ""
             expect: "Hello, World! From .NET NativeAOT on Hyperlight"
           - example: hostfs-posix-c
-            memory: "16Mi"
             args: ""
             expect: "done\\."
             needs_mount: true
           - example: hostfs-posix-py
-            memory: "512Mi"
             args: "-- /hostfs_demo.py"
             expect: "done\\."
             needs_mount: true
           - example: multifn-c
-            memory: "4Mi"
             args: ""
             expect: "RUN: world"
             driver: multifn-test
           - example: python-agent
-            memory: "1Gi"
             args: "-- /agent.py"
             expect: "done\\."
             needs_mount: true
           - example: python-agent-driver
-            memory: "2Gi"
             args: ""
             expect: "hello from driver"
             driver: pydriver-run
           - example: powershell
-            memory: "1Gi"
             args: "-- -NoProfile -File /scripts/hello.ps1"
             expect: "Hello, World! From PowerShell on Hyperlight"
           - example: networking-py
-            memory: "512Mi"
             args: "--net -- /urllib_get.py"
             expect: "SUCCESS: urllib GET worked!"
           - example: networking-py
-            memory: "512Mi"
             args: "--port 8080 -- /echo_server_test.py"
             expect: "SUCCESS: bind\\+listen on port 8080 allowed"
     steps:
@@ -614,10 +594,19 @@ jobs:
           $cpio   = (Resolve-Path "image/initrd.cpio").Path
           $expect = '${{ matrix.expect }}'
           $driver = '${{ matrix.driver }}'
-          $memory = '${{ matrix.memory }}'
           $runArgs = '${{ matrix.args }}'
           $needsMount = '${{ matrix.needs_mount }}'
 
+          # Read memory from the example's Justfile (single source of truth).
+          $memory = ''
+          $justfile = "examples/${{ matrix.example }}/Justfile"
+          if (Test-Path $justfile) {
+            $memLine = Get-Content $justfile | Where-Object { $_ -match '^\s*memory\s*:=' }
+            if ($memLine -match '"([^"]+)"') {
+              $memory = $Matches[1]
+            }
+          }
+
           $mountArgs = @()
           if ($needsMount -eq 'true') {
             $mountDir = Join-Path $env:RUNNER_TEMP ('hostfs-' + '${{ matrix.example }}')
@@ -649,7 +638,11 @@ jobs:
               if ($runArgs -ne '') {
                 $argList = $runArgs.Split(' ') | Where-Object { $_ -ne '' }
               }
-              $out = & hyperlight-unikraft -q -m $memory `
+              $memArgs = @()
+              if ($memory -ne '') {
+                $memArgs = @('-m', $memory)
+              }
+              $out = & hyperlight-unikraft -q @memArgs `
                 $kernel --initrd $cpio @mountArgs @argList 2>&1
               $rc = $LASTEXITCODE
             }
diff --git a/examples/dotnet-nativeaot/Justfile b/examples/dotnet-nativeaot/Justfile
@@ -11,7 +11,7 @@ export DOCKER_BUILDKIT := "0"
 
 kernel      := ".unikraft/build/dotnet-nativeaot-hyperlight_hyperlight-x86_64"
 initrd      := "hello-initrd.cpio"
-memory      := "16Mi"
+memory      := "8Mi"
 image       := "dotnet-nativeaot-hyperlight"
 ghcr_kernel := "ghcr.io/hyperlight-dev/hyperlight-unikraft/dotnet-nativeaot-kernel:latest"
 
diff --git a/examples/helloworld-c/Justfile b/examples/helloworld-c/Justfile
@@ -11,7 +11,7 @@ export DOCKER_BUILDKIT := "0"
 
 kernel      := ".unikraft/build/helloworld-hyperlight_hyperlight-x86_64"
 initrd      := "hello-initrd.cpio"
-memory      := "4Mi"
+memory      := "2Mi"
 image       := "helloworld-c-hyperlight"
 ghcr_kernel := "ghcr.io/hyperlight-dev/hyperlight-unikraft/helloworld-c-kernel:latest"
 
diff --git a/examples/hostfs-posix-c/Justfile b/examples/hostfs-posix-c/Justfile
@@ -8,7 +8,7 @@ export DOCKER_BUILDKIT := "0"
 
 kernel      := ".unikraft/build/hostfs-posix-c-hyperlight_hyperlight-x86_64"
 initrd      := "hostfs-posix-c-initrd.cpio"
-memory      := "16Mi"
+memory      := "2Mi"
 image       := "hostfs-posix-c-hyperlight"
 ghcr_kernel := "ghcr.io/hyperlight-dev/hyperlight-unikraft/hostfs-posix-c-kernel:latest"
 mount_dir   := "./work"
diff --git a/examples/hostfs-posix-py/Justfile b/examples/hostfs-posix-py/Justfile
@@ -8,7 +8,7 @@ export DOCKER_BUILDKIT := "0"
 
 kernel      := ".unikraft/build/hostfs-posix-py-hyperlight_hyperlight-x86_64"
 initrd      := "hostfs-posix-py-initrd.cpio"
-memory      := "96Mi"
+memory      := "512Mi"
 image       := "hostfs-posix-py-hyperlight"
 ghcr_kernel := "ghcr.io/hyperlight-dev/hyperlight-unikraft/hostfs-posix-py-kernel:latest"
 mount_dir   := "./work"
diff --git a/examples/networking-py/Justfile b/examples/networking-py/Justfile
@@ -11,7 +11,7 @@ export DOCKER_BUILDKIT := "0"
 
 kernel      := ".unikraft/build/networking-py-hyperlight_hyperlight-x86_64"
 initrd      := "initrd.cpio"
-memory      := "512Mi"
+memory      := "32Mi"
 image       := "networking-py-hyperlight"
 
 # Run HTTP GET test (raw sockets)
diff --git a/examples/python-tools/Justfile b/examples/python-tools/Justfile
@@ -11,7 +11,7 @@ export DOCKER_BUILDKIT := "0"
 
 kernel      := ".unikraft/build/python-tools-hyperlight_hyperlight-x86_64"
 initrd      := "initrd.cpio"
-memory      := "96Mi"
+memory      := "512Mi"
 image       := "python-tools-hyperlight"
 ghcr_kernel := "ghcr.io/hyperlight-dev/hyperlight-unikraft/python-tools-kernel:latest"
 
diff --git a/host/src/main.rs b/host/src/main.rs
@@ -27,8 +27,8 @@ struct Args {
     #[arg(long)]
     initrd: Option<PathBuf>,
 
-    /// Memory allocation (e.g., 256Mi, 512Mi, 1Gi)
-    #[arg(long, short = 'm', default_value = "512Mi")]
+    /// Memory allocation (e.g., 32Mi, 256Mi, 1Gi)
+    #[arg(long, short = 'm', default_value = "32Mi")]
     memory: String,
 
     /// Stack size (e.g., 8Mi)
