- It looks incorrect to use blk_rq_map_sg with pci_map_page here about
  DMA mappings. dma_map_sg?

- better to use dma_map_page instead of pci_map_page.
  http://marc.info/?l=linux-kernel&m=126596737604808&w=2

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

Updated 'nomerges' tunable to accept a value of '2' - indicating that _no_
merges at all are to be attempted (not even the simple one-hit cache).

The following table illustrates the additional benefit - 5 minute runs of
a random I/O load were applied to a dozen devices on a 16-way x86_64 system.

nomerges        Throughput      %System         Improvement (tput / %sys)
--------        ------------    -----------     -------------------------
0               12.45 MB/sec    0.669365609
1               12.50 MB/sec    0.641519199     0.40% / 2.71%
2               12.52 MB/sec    0.639849750     0.56% / 2.96%

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

It seems that Documentation/DMA-mapping.txt was supposed to be renamed
to Documentation/PCI/PCI-DMA-mapping.txt.

Signed-off-by: Kusanagi Kouichi <slash@ac.auone-net.jp>
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Commit 492af6350a5ccf087e4964104a276ed358811458 removed
the AS IO scheduler, so remove its documentation too.

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

Signed-off-by: Andre Noll <maan@systemlinux.org>
Acked-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

Fix various typos in documentation txts.

Signed-off-by: Matt LaPlante <kernel1@cyberdogtech.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

File Documentation/PCI/PCI-DMA-mapping.txt does not exist.
 Documentation/DMA-mapping.txt contains DMA Mapping details

Signed-off-by: vibi sreenivasan <vibi_sreenivasan@cms.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

We do per-device plugging, get rid of any references to tq_disk as that
has been dead since 2.6.5 or so.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

These lines appear in this file twice - removed one occurrence.

Signed-off-by: Avishay Traeger <avishay@il.ibm.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>