Set GOMAXPROCS=runtime.NumCPU().

client/cmd/swarming/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"
         "os"
+        "runtime"
 
         "github.com/luci/luci-go/client/internal/common"
         "github.com/luci/luci-go/client/internal/lhttp"
         "github.com/maruel/subcommands"
 )
 
+func init() {
+        runtime.GOMAXPROCS(runtime.NumCPU())
+}
+
 type commonFlags struct {
         subcommands.CommandRunBase
         defaultFlags common.Flags
         serverURL    string
 }
 
 // Init initializes common flags.
 func (c *commonFlags) Init() {
         c.defaultFlags.Init(&c.Flags)
         c.Flags.StringVar(&c.serverURL, "server", os.Getenv("SWARMING_SERVER"), "Server URL; required. Set $SWARMING_SERVER to set a default.")
@@ skipping 11 matching lines @@
         if err != nil {
                 return err
         }
         c.serverURL = s
         return nil
 }
 
 func (c *commonFlags) Close() error {
         return c.defaultFlags.Close()
 }