title: Can the dirtiness of pages of a mmap be found from userspace?
body: <p>Can dirtiness of pages of a (non-shared) mmap be accessed from userspace under linux 2.6.30+?  Platform-specific hacks and kludges welcome.</p>
  
  <p>Ideally, I'm looking for an array of bits, one per page (4kB?) of the mmap'ed region, which are set if that page has been written to since the region was mmap'ed.</p>
  
  <p>(I am aware, that the process doing the writing could keep track of this information - but it seems silly to do so if the kernel is doing it anyway.)</p>
  
  <p>Thanks,</p>
  
  <p>Chris.</p>