1. 27 Jun, 2005 2 commits
    • Jens Axboe's avatar
      [PATCH] CFQ io scheduler updates · 3b18152c
      Jens Axboe authored
      
      
      - Adjust slice values
      
      - Instead of one async queue, one is defined per priority level. This
        prevents kernel threads (such as reiserfs/x and others) that run at
        higher io priority from conflicting with others. Previously, it was a
        coin toss what io prio the async queue got, it was defined by who
        first set up the queue.
      
      - Let a time slice only begin, when the previous slice is completely
        done. Previously we could be somewhat unfair to a new sync slice, if
        the previous slice was async and had several ios queued. This might
        need a little tweaking if throughput suffers a little due to this,
        allowing perhaps an overlap of a single request or so.
      
      - Optimize the calling of kblockd_schedule_work() by doing it only when
        it is strictly necessary (no requests in driver and work left to do).
      
      - Correct sync vs async logic. A 'normal' process can be purely async as
        well, and a flusher can be purely sync as well. Sync or async is now a
        property of the class defined and requests pending. Previously writers
        could be considered sync, when they were really async.
      
      - Get rid of the bit fields in cfqq and crq, use flags instead.
      
      - Various other cleanups and fixes
      Signed-off-by: default avatarJens Axboe <axboe@suse.de>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      3b18152c
    • Jens Axboe's avatar
      [PATCH] Update cfq io scheduler to time sliced design · 22e2c507
      Jens Axboe authored
      
      
      This updates the CFQ io scheduler to the new time sliced design (cfq
      v3).  It provides full process fairness, while giving excellent
      aggregate system throughput even for many competing processes.  It
      supports io priorities, either inherited from the cpu nice value or set
      directly with the ioprio_get/set syscalls.  The latter closely mimic
      set/getpriority.
      
      This import is based on my latest from -mm.
      Signed-off-by: default avatarJens Axboe <axboe@suse.de>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      22e2c507