为什么（进程文件“git”）在Emacs for Windows上比（process-file-shell-command“git”）慢

Question

在Emacs for Windows上，

(process-file "git")比(process-file-shell-command "git")慢。

我的环境：

• Windows 7
• GNU Emacs 24.2.1

• git版本1.8.5.2.msysgit.0

  (benchmark 10 '(process-file "git"))
  => "Elapsed time: 4.309000s"
  
  (benchmark 10 '(process-file-shell-command "git"))
  => "Elapsed time: 0.351000s"
  

我和Cygwin git得到了相同的结果。

(benchmark 10 '(process-file "c:/cygwin/bin/git.exe"))
=> "Elapsed time: 5.583000s"

(benchmark 10 '(process-file-shell-command "c:/cygwin/bin/git.exe"))
=> "Elapsed time: 0.371000s"