Set GOMAXPROCS=runtime.NumCPU().

client/cmd/isolate/common.go

 // Copyright 2015 The Chromium 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 main
 
 import (
         "errors"
         "flag"
         "fmt"
+        "runtime"
 
         "github.com/luci/luci-go/client/internal/common"
         "github.com/luci/luci-go/client/isolate"
         "github.com/luci/luci-go/client/isolatedclient"
         "github.com/maruel/subcommands"
 )
 
+func init() {
+        runtime.GOMAXPROCS(runtime.NumCPU())
+}
+
 type commonFlags struct {
         subcommands.CommandRunBase
         defaultFlags common.Flags
 }
 
 func (c *commonFlags) Init() {
         c.defaultFlags.Init(&c.Flags)
 }
 
 func (c *commonFlags) Parse() error {
@@ skipping 78 matching lines @@
 
         if flags&RequireIsolateFile != 0 && c.Isolate == "" {
                 return errors.New("-isolate must be specified")
         }
         if flags&RequireIsolatedFile != 0 && c.Isolated == "" {
                 return errors.New("-isolated must be specified")
         }
 
         return nil
 }