Move Linux client & common packages into a public repo.

wgengine/rusage.go

@@ -0,0 +1,21 @@
+// Copyright (c) 2020 Tailscale Inc & AUTHORS All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package wgengine
+
+import (
+	"fmt"
+	"runtime"
+)
+
+func RusagePrefixLog(logf func(f string, argv ...interface{})) func(f string, argv ...interface{}) {
+	return func(f string, argv ...interface{}) {
+		var m runtime.MemStats
+		runtime.ReadMemStats(&m)
+		goMem := float64(m.HeapInuse+m.StackInuse) / (1 << 20)
+		maxRSS := rusageMaxRSS()
+		pf := fmt.Sprintf("%.1fM/%.1fM %s", goMem, maxRSS, f)
+		logf(pf, argv...)
+	}
+}