Add SIO I/O scheduler

Signed-off-by: Paul Reioux <reioux@gmail.com>

Conflicts:
	block/Kconfig.iosched
	block/Makefile
arch/arm/mach-msm/cpufreq.c: reduce dmesg log spam

Signed-off-by: Paul Reioux <reioux@gmail.com>

Conflicts:
	arch/arm/mach-msm/cpufreq.c
Max Readahead to 1024 kB.

* This values was optimal from my testing.

Signed-off-by: Chester Kener <Cl3Kener@gmail.com>
AIO: Don't plug the I/O queue in do_io_submit() Asynchronous I/O latency to a solid-state disk greatly increased between the 2.6.32 and 3.0 kernels. By removing the plug from do_io_submit(), we observed a 34% improvement in the I/O latency.

Unfortunately, at this level, we don't know if the request is to
a rotating disk or not.

Change-Id: I7101df956473ed9fd5dcff18e473dd93b688a5c1
Signed-off-by: Dave Kleikamp <dave.kleikamp@oracle.com>
Cc: linux-aio@kvack.org
Cc: Chris Mason <chris.mason@oracle.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Francisco Franco <franciscofranco.1990@gmail.com>
sched: LOAD_FREQ (4*HZ+61) avoids loadavg Moire. From http://ripke.com/loadavg/moire

Signed-off-by: franciscofranco <franciscofranco.1990@gmail.com>
block: row: add magic values.

Signed-off-by: franciscofranco <franciscofranco.1990@gmail.com>