title: git stash is slow on windows
body: <p>On my windows machine <code>git stash</code> has about 3.5 seconds overhead on each invocation, which adds about 7 seconds to my git commit hook.</p>
  
  <p>The same command under linux (same machine) takes about 0.01 seconds. The performance issue applies to empty repositories as well.</p>
  
  <p>I have tried the following from <a href="https://stackoverflow.com/questions/4485059/git-bash-is-extremely-slow-in-windows-7-x64">this thread</a> and <a href="https://stackoverflow.com/questions/2835775/msysgit-bash-is-horrendously-slow-in-windows-7/2967519#2967519">this thread</a>:</p>
  
  <ul>
  <li><code>core.fscache</code> is set to <code>true</code></li>
  <li><code>core.preloadindex</code> is set to <code>true</code></li>
  <li><code>gc.auto</code> is set to <code>256</code></li>
  <li>Setting PS1='$ '</li>
  <li>Running cmd in administration mode</li>
  <li>Running inside <em>cmd.exe</em> instead of git-bash</li>
  </ul>
  
  <p>Running <code>GIT_TRACE=true git stash list</code></p>
  
  <pre><code>16:58:16.844591 git.c:563               trace: exec: 'git-stash' 'list'
  16:58:16.844591 run-command.c:336       trace: run_command: 'git-stash' 'list'
  16:58:19.699591 git.c:350               trace: built-in: git 'rev-parse' '--git-dir'
  16:58:19.859591 git.c:350               trace: built-in: git 'rev-parse' '--git-path' 'objects'
  16:58:20.069591 git.c:350               trace: built-in: git 'rev-parse' '--show-toplevel'
  16:58:20.154591 git.c:350               trace: built-in: git 'rev-parse' '--git-path' 'index'
  16:58:20.244591 git.c:350               trace: built-in: git 'config' '--get-colorbool' 'color.interactive'
  16:58:20.334591 git.c:350               trace: built-in: git 'config' '--get-color' 'color.interactive.help' 'red bold'
  16:58:20.424591 git.c:350               trace: built-in: git 'config' '--get-color' '' 'reset'
  16:58:20.514591 git.c:350               trace: built-in: git 'rev-parse' '--verify' '--quiet' 'refs/stash'
  
  real    0m3.845s
  user    0m0.000s
  sys     0m0.047s
  </code></pre>
  
  <p>Running <code>GIT_TRACE_PERFORMANCE=true git stash list</code></p>
  
  <pre><code>16:59:18.414591 trace.c:420             performance: 0.001078046 s: git command: 'C:\Program Files\Git\mingw64\libexec\git-core\git.exe' 'rev-parse' '--git-dir'                                          
  16:59:18.569591 trace.c:420             performance: 0.000947184 s: git command: 'C:\Program Files\Git\mingw64\libexec\git-core\git.exe' 'rev-parse' '--git-path' 'objects'                               
  16:59:18.779591 trace.c:420             performance: 0.001253627 s: git command: 'C:\Program Files\Git\mingw64\libexec\git-core\git.exe' 'rev-parse' '--show-toplevel'                                    
  16:59:18.869591 trace.c:420             performance: 0.001285517 s: git command: 'C:\Program Files\Git\mingw64\libexec\git-core\git.exe' 'rev-parse' '--git-path' 'index'                                 
  16:59:18.955591 trace.c:420             performance: 0.001139994 s: git command: 'C:\Program Files\Git\mingw64\libexec\git-core\git.exe' 'config' '--get-colorbool' 'color.interactive'                   
  16:59:19.040591 trace.c:420             performance: 0.001182881 s: git command: 'C:\Program Files\Git\mingw64\libexec\git-core\git.exe' 'config' '--get-color' 'color.interactive.help' 'red bold'       
  16:59:19.125591 trace.c:420             performance: 0.001128997 s: git command: 'C:\Program Files\Git\mingw64\libexec\git-core\git.exe' 'config' '--get-color' '' 'reset'                                
  16:59:19.215591 trace.c:420             performance: 0.001567766 s: git command: 'C:\Program Files\Git\mingw64\libexec\git-core\git.exe' 'rev-parse' '--verify' '--quiet' 'refs/stash'                    
  16:59:19.295591 trace.c:420             performance: 3.730583540 s: git command: 'C:\Program Files\Git\mingw64\bin\git.exe' 'stash' 'list'                                                                
  
  real    0m3.819s                                                                                                                                                                                          
  user    0m0.000s                                                                                                                                                                                          
  sys     0m0.062s                                                                                                                                                                                          
  </code></pre>
  
  <p>From the log we see that it takes around 3 seconds between the git-stash command is run and the git-rev-parse is run. Are there any other flags I can run to find the bottleneck?</p>