[PATCH] Time sliced cfq ver13

[PATCH] Time sliced cfq ver13

[Jens Axboe]

Hi,

2.6.10-rc3-mm1 patch:

http://www.kernel.org/pub/linux/kernel/people/axboe/patches/v2.6/2.6.10-rc3-mm1/cfq-time-slices-13-2.6.10-rc3-mm1.gz

2.6-BK patch:

http://www.kernel.org/pub/linux/kernel/people/axboe/patches/v2.6/2.6.10-rc3/cfq-time-slices-13.gz

Changes:

- Fixup the RCU usage. Also uncovered a bug if the process exiting was
  active on several disks, only the first would get kicked.

- Fix problem with CFQ as default at boot for IDE. IDE asks for the same
  request several times, this disturbed the CFQ max_depth logic. Check
  if a request is already in flight and allow it.

-- 
Jens Axboe

[PATCH] Time sliced cfq ver14

[Jens Axboe]

Hi,

2.6.10-rc3-mm1 patch:

http://www.kernel.org/pub/linux/kernel/people/axboe/patches/v2.6/2.6.10-rc3-mm1/cfq-time-slices-14-2.6.10-rc3-mm1.gz

2.6-BK patch:

http://www.kernel.org/pub/linux/kernel/people/axboe/patches/v2.6/2.6.10-rc3/cfq-time-slices-14.gz

Changes:

- Fix leak of queue

- Better balance when to preempt. On 8 client read workload, aggregate
  bandwidth would take a few seconds to build up, due to initial massive
  preempt generation more seeks than it should. Priority check was also
  reverse which showed bad results on multi-prio work loads.

- Fix reversed priority check in preemption check, oops.

-- 
Jens Axboe

[PATCH] Time sliced cfq ver17

[Jens Axboe]

Hi,

2.6.10-rc3-mm1 patch:

http://www.kernel.org/pub/linux/kernel/people/axboe/patches/v2.6/2.6.10-rc3-mm1/cfq-time-slices-17-2.6.10-rc3-mm1.gz

2.6-BK patch:

http://www.kernel.org/pub/linux/kernel/people/axboe/patches/v2.6/2.6.10-rc3/cfq-time-slices-17.gz

Changes:

- Kill the spare queue logic

- wait_request should not imply that queue must be allowed to allocate a
  request, otherwise a write could quickly flood the queue. Add
  must_alloc to handle that and make it one-shot.

- Turn on/off idle window based on process think time and seek time.
  Improve idle timer logic. The seek/think time updates toggle the
  idle_window flag and increase queuing depth if we disable the idle
  window.

- Improve SCSI requeing logic. Add request fully back into cfq queue but
  mark it as next service once this queue gets slice time again.

- More preemption fixes. Allow new sync io to preempt equal priority
  async io to improve reader fairness.

-- 
Jens Axboe