how to grant a user to only access the performance area of the configuration screen drupal 7
you can write a simple custom module to do this for you.
as you can see.with hook_menu_alter you can alter all menu in drupal. And by overriding it's access callback you can have your custom function to grant access to your users. Here is a sample code that check if user has an 'editor' role.then it return true and user can access performance.

function MYMODULE_menu_alter(&amp;$items) {
  $items['admin/config/development/performance']['access callback'] = '_accesscheck';
}

function _accesscheck(){
  global $user;
  if(in_array('editor', $user-&gt;roles)){
     return TRUE;
  }
  return FALSE;
}