pkg/limayaml: adjust the default CPUs and memory size

CPUs: 4 → min(4, host CPU cores)
Memory: 4GiB → min(4 GiB, half of host memory)

Signed-off-by: Akihiro Suda <[email protected]>

Author: AkihiroSuda

examples/default.yaml

@@ -33,12 +33,12 @@ images:
 - location: "https://cloud-images.ubuntu.com/releases/23.04/release/ubuntu-23.04-server-cloudimg-arm64.img"
   arch: "aarch64"
 
-# CPUs: if you see performance issues, try limiting cpus to 1.
-# 🟢 Builtin default: 4
+# CPUs
+# 🟢 Builtin default: min(4, host CPU cores)
 cpus: null
 
 # Memory size
-# 🟢 Builtin default: "4GiB"
+# 🟢 Builtin default: min("4GiB", half of host memory)
 memory: null
 
 # Disk size

go.mod

@@ -31,6 +31,7 @@ require (
 	github.com/mikefarah/yq/v4 v4.34.1
 	github.com/nxadm/tail v1.4.8
 	github.com/opencontainers/go-digest v1.0.0
+	github.com/pbnjay/memory v0.0.0-20210728143218-7b4eea64cf58
 	github.com/sethvargo/go-password v0.2.0
 	github.com/sirupsen/logrus v1.9.3
 	github.com/spf13/cobra v1.7.0

go.sum

@@ -236,6 +236,8 @@ github.com/onsi/ginkgo/v2 v2.4.0 h1:+Ig9nvqgS5OBSACXNk15PLdp0U9XPYROt9CFzVdFGIs=
 github.com/onsi/gomega v1.27.4 h1:Z2AnStgsdSayCMDiCU42qIz+HLqEPcgiOCXjAU/w+8E=
 github.com/opencontainers/go-digest v1.0.0 h1:apOUWs51W5PlhuyGyz9FCeeBIOUDA/6nW8Oi/yOhh5U=
 github.com/opencontainers/go-digest v1.0.0/go.mod h1:0JzlMkj0TRzQZfJkVvzbP0HBR3IKzErnv2BNG4W4MAM=
+github.com/pbnjay/memory v0.0.0-20210728143218-7b4eea64cf58 h1:onHthvaw9LFnH4t2DcNVpwGmV9E1BkGknEliJkfwQj0=
+github.com/pbnjay/memory v0.0.0-20210728143218-7b4eea64cf58/go.mod h1:DXv8WO4yhMYhSNPKjeNKa5WY9YCIEBRbNzFFPJbWO6Y=
 github.com/pelletier/go-toml/v2 v2.0.7 h1:muncTPStnKRos5dpVKULv2FVd4bMOhNePj9CjgDb8Us=
 github.com/pelletier/go-toml/v2 v2.0.7/go.mod h1:eumQOmlWiOPt5WriQQqoM5y18pDHwha2N+QD+EUNTek=
 github.com/pierrec/lz4 v2.3.0+incompatible/go.mod h1:pdkljMzZIN41W+lC3N2tnIh5sFi+IEE17M5jbnwPHcY=

pkg/limayaml/defaults.go

@@ -11,7 +11,9 @@ import (
 	"strconv"
 	"text/template"
 
+	"github.com/docker/go-units"
 	"github.com/lima-vm/lima/pkg/networks"
+	"github.com/pbnjay/memory"
 
 	"github.com/lima-vm/lima/pkg/guestagent/api"
 	"github.com/lima-vm/lima/pkg/osutil"
@@ -76,6 +78,31 @@ func MACAddress(uniqueID string) string {
 	return hw.String()
 }
 
+func defaultCPUs() int {
+	const x = 4
+	if hostCPUs := runtime.NumCPU(); hostCPUs < x {
+		return hostCPUs
+	}
+	return x
+}
+
+func defaultMemory() uint64 {
+	const x uint64 = 4 * 1024 * 1024 * 1024
+	if halfOfHostMemory := memory.TotalMemory() / 2; halfOfHostMemory < x {
+		return halfOfHostMemory
+	}
+	return x
+}
+
+func defaultMemoryAsString() string {
+	return units.BytesSize(float64(defaultMemory()))
+}
+
+func defaultDiskSizeAsString() string {
+	// currently just hardcoded
+	return "100GiB"
+}
+
 // FillDefault updates undefined fields in y with defaults from d (or built-in default), and overwrites with values from o.
 // Both d and o may be empty.
 //
@@ -174,7 +201,7 @@ func FillDefault(y, d, o *LimaYAML, filePath string) {
 		y.CPUs = o.CPUs
 	}
 	if y.CPUs == nil || *y.CPUs == 0 {
-		y.CPUs = pointer.Int(4)
+		y.CPUs = pointer.Int(defaultCPUs())
 	}
 
 	if y.Memory == nil {
@@ -184,7 +211,7 @@ func FillDefault(y, d, o *LimaYAML, filePath string) {
 		y.Memory = o.Memory
 	}
 	if y.Memory == nil || *y.Memory == "" {
-		y.Memory = pointer.String("4GiB")
+		y.Memory = pointer.String(defaultMemoryAsString())
 	}
 
 	if y.Disk == nil {
@@ -194,7 +221,7 @@ func FillDefault(y, d, o *LimaYAML, filePath string) {
 		y.Disk = o.Disk
 	}
 	if y.Disk == nil || *y.Disk == "" {
-		y.Disk = pointer.String("100GiB")
+		y.Disk = pointer.String(defaultDiskSizeAsString())
 	}
 
 	y.AdditionalDisks = append(append(o.AdditionalDisks, y.AdditionalDisks...), d.AdditionalDisks...)

pkg/limayaml/defaults_test.go

@@ -59,9 +59,9 @@ func TestFillDefault(t *testing.T) {
 			X8664:   "qemu64",
 			RISCV64: "rv64",
 		},
-		CPUs:   pointer.Int(4),
-		Memory: pointer.String("4GiB"),
-		Disk:   pointer.String("100GiB"),
+		CPUs:   pointer.Int(defaultCPUs()),
+		Memory: pointer.String(defaultMemoryAsString()),
+		Disk:   pointer.String(defaultDiskSizeAsString()),
 		Containerd: Containerd{
 			System:   pointer.Bool(false),
 			User:     pointer.Bool(true),