Some IO scheduler cleanup in Documentation/block

as-iosched.txt:
  o  Changed IO scheduler selection text to a reference to the
     switching-sched.txt file.

  o  Fixed typo: 'for up time...' -> 'for up to...'

  o  Added short description of the est_time file.

deadline-iosched.txt:
  o  Changed IO scheduler selection text to a reference to the
     switching-sched.txt file.

  o  Removed references to non-existent seek-cost and stream_unit.

  o  Fixed typo: 'write_starved' -> 'writes_starved'

switching-sched.txt:
  o  Added in boot-time argument to set the default IO scheduler. (From
     as-iosched.txt)

  o  Added in sysfs mount instructions. (From deadline-iosched.txt)

Signed-off-by: Alan D. Brunelle <Alan.Brunelle@hp.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

1 files changed, 7 insertions, 16 deletions

diff --git a/Documentation/block/deadline-iosched.txt b/Documentation/block/deadline-iosched.txt
index 03775dd99983..c23cab13c3d1 100644
--- a/Documentation/block/deadline-iosched.txt
+++ b/Documentation/block/deadline-iosched.txt
@@ -5,16 +5,10 @@ This little file attempts to document how the deadline io scheduler works.
 In particular, it will clarify the meaning of the exposed tunables that may be
 of interest to power users.
 
-Each io queue has a set of io scheduler tunables associated with it. These
-tunables control how the io scheduler works. You can find these entries
-in:
-
-/sys/block/<device>/queue/iosched
-
-assuming that you have sysfs mounted on /sys. If you don't have sysfs mounted,
-you can do so by typing:
-
-# mount none /sys -t sysfs
+Selecting IO schedulers
+-----------------------
+Refer to Documentation/block/switching-sched.txt for information on
+selecting an io scheduler on a per-device basis.
 
 
 ********************************************************************************
@@ -41,14 +35,11 @@ fifo_batch
 
 When a read request expires its deadline, we must move some requests from
 the sorted io scheduler list to the block device dispatch queue. fifo_batch
-controls how many requests we move, based on the cost of each request. A
-request is either qualified as a seek or a stream. The io scheduler knows
-the last request that was serviced by the drive (or will be serviced right
-before this one). See seek_cost and stream_unit.
+controls how many requests we move.
 
 
-write_starved   (number of dispatches)
--------------
+writes_starved  (number of dispatches)
+--------------
 
 When we have to move requests from the io scheduler queue to the block
 device dispatch queue, we always give a preference to reads. However, we