title: Git hangs with 100% cpu usage (it was disk issue)
body: <p>There are some operations that hang on one of my repositories:</p>
  
  <ul>
  <li>git gc: hangs with 100% usage at "Counting objects: 7409"</li>
  <li><p>when I launch gitk, it launches this command, which also hangs with 100% CPU usage:</p>
  
  <p>git log --no-color -z --pretty=raw --parents --boundary 6ca9fbc0393cbc05e6ef7d67768ff1570e3fc42e 5741492043ebbc19013baf8c1c162b32b0e37ce5 6732226ff033e0d0dcdb47aa5c69d09551252caa 16871466fdae51bbf3dbeabd5dfbf2b02d4da03b e87ffba9df6cd03e0ea1c91821e8f2d3f0af2ca6 fb6abea427f3f4770caed5a4b31deeac606d5391 08671dcf23c663efa9758006af71e3281c119bc8 7cdbf2f37bc64ec765c961af0d6bd301f1cc0826 239d75a028f0eb6141ab5d32b008994367f08edf d6c135ae2ce4a099dfc444dba1e5bd29c7a82e2e 80d40034e9bd2eca48b2833a7846fd097a4e3f60 5741492043ebbc19013baf8c1c162b32b0e37ce5 faf15d38deb1abc2359f6d40315cf089331ba01b f0f1feaf60dea3eae104e5d09a3edb0dcb7f22a3 d9758d39749aa1717d43cf5483027a006f41f09c dccc73a3107c69f8020dce655c2eb10c6d0a6e2f d9758d39749aa1717d43cf5483027a006f41f09c 16e784817e8c4fa4bfcca4e2f985c0c0f9e9219f 418cf50a6e4c5a566d0d962e1aa2036e370ba4d3 7cdbf2f37bc64ec765c961af0d6bd301f1cc0826 --</p></li>
  </ul>
  
  <p>I can otherwise operate normally on this repository, but not being able to gc is slowly killing the performance...</p>
  
  <p>I'm on Windows 2003 x86. Tried msysGit and cygwin git with identical results. This problem started 2 or 3 days ago, it used to work flawlessly...</p>