1. 29 Aug, 2017 39 commits
  2. 28 Aug, 2017 1 commit
    • Linus Torvalds's avatar
      page waitqueue: always add new entries at the end · 9c3a815f
      Linus Torvalds authored
      Commit 3510ca20 ("Minor page waitqueue cleanups") made the page
      queue code always add new waiters to the back of the queue, which helps
      upcoming patches to batch the wakeups for some horrid loads where the
      wait queues grow to thousands of entries.
      
      However, I forgot about the nasrt add_page_wait_queue() special case
      code that is only used by the cachefiles code.  That one still continued
      to add the new wait queue entries at the beginning of the list.
      
      Fix it, because any sane batched wakeup will require that we don't
      suddenly start getting new entries at the beginning of the list that we
      already handled in a previous batch.
      
      [ The current code always does the whole list while holding the lock, so
        wait queue ordering doesn't matter for correctness, but even then it's
        better to add later entries at the end from a fairness standpoint ]
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      9c3a815f