fs/dyn_sync_cntrl: dynamic sync control

The dynamic sync control interface uses Android kernel's unique early
suspend / lat resume interface.

While screen is on, file sync is disabled
when screen is off, a file sync is called to flush all outstanding writes
and restore file sync operation as normal.

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

Conflicts:
	fs/Makefile
	fs/sync.c
fs/dyn_sync_cntrl: check dyn fsync control's active prior to performing fsync ops

Signed-off-by: Andrew Bartholomew <andrewb03@gmail.com>
fs/dyn_sync_cntrl: add some cache optimizations

and clean up file format and typos

bump version to 1.1

Signed-off-by: Paul Reioux <reioux@gmail.com>
fs/dyn_sync_cntrl: favor true case since most will be using this feature

Signed-off-by: Paul Reioux <reioux@gmail.com>
fs/dyn_sync_cntrl: add reboot notifier to force flush outstanding data

this should further prevent data corruption from kernel panics and
forced reboots

bump version to 1.2

Signed-off-by: Paul Reioux <reioux@gmail.com>
fs/dyn_sync_cntrl: add kernel panic notifier to force flush outstanding data

more paranoia safety checks

Signed-off-by: Paul Reioux <reioux@gmail.com>
Enabled Dynamic FSync and set higher readahead

Conflicts:
	arch/arm/configs/GearKernelJB_galaxys_defconfig
	include/linux/mm.h
ARM: compressed/head.S: work around new binutils warning

In August 2012, Matthew Gretton-Dann checked a change
into binutils labelled "Error on obsolete & warn on
deprecated registers", apparently as part of ARMv8
support. Apparently, this was supposed to emit
the message "Warning: This coprocessor register access
is deprecated in ARMv8" when using certain mcr/mrc
instructions and building for ARMv8. Unfortunately,
the message that is actually emitted appears to be
'(null)', which is less helpful in comparison.

Even more unfortunately, this is biting us on
every single kernel build with a new gas, because
arch/arm/boot/compressed/head.S and some other files
in that directory are built with -march=all since
kernel commit 80cec14a8 "[ARM] Add -march=all to
assembly file build in arch/arm/boot/compressed"
back in v2.6.28.

This patch reverts Russell's nice solution and
replaces it with a more complex one that sprinkles
.arch statements inside of the head.S file in
functions that are executed in different architecture
levels, which seems to solve the original problem
just as well, and gets rid of the new one, too.

Without this patch, building anything results in:

arch/arm/boot/compressed/head.S: Assembler messages:
arch/arm/boot/compressed/head.S:565: Warning: (null)
arch/arm/boot/compressed/head.S:676: Warning: (null)
arch/arm/boot/compressed/head.S:698: Warning: (null)
arch/arm/boot/compressed/head.S:722: Warning: (null)
arch/arm/boot/compressed/head.S:726: Warning: (null)
arch/arm/boot/compressed/head.S:957: Warning: (null)
arch/arm/boot/compressed/head.S:996: Warning: (null)
arch/arm/boot/compressed/head.S:997: Warning: (null)
arch/arm/boot/compressed/head.S:1027: Warning: (null)
arch/arm/boot/compressed/head.S:1035: Warning: (null)
arch/arm/boot/compressed/head.S:1046: Warning: (null)
arch/arm/boot/compressed/head.S:1060: Warning: (null)
arch/arm/boot/compressed/head.S:1092: Warning: (null)
arch/arm/boot/compressed/head.S:1094: Warning: (null)
arch/arm/boot/compressed/head.S:1095: Warning: (null)
arch/arm/boot/compressed/head.S:1102: Warning: (null)
arch/arm/boot/compressed/head.S:1134: Warning: (null)

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Matthew Gretton-Dann <matthew.gretton-dann@arm.com>
Cc: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Paul Beeler <sparksco@gmail.com>
Performance regression from switching lock to rw-sem for anon-vma tree

On 06/14/2013 07:43 AM, Davidlohr Bueso wrote:
> I was hoping that the lack of spin on owner was the main difference with
> rwsems and am/was in the middle of implementing it. Could you send your
> patch so I can give it a try on my workloads?
>
> Note that there have been a few recent (3.10) changes to mutexes that
> give a nice performance boost, specially on large systems, most
> noticeably:
>
> commit 2bd2c92c (mutex: Make more scalable by doing less atomic
> operations)
>
> commit 0dc8c730 (mutex: Queue mutex spinners with MCS lock to reduce
> cacheline contention)
>
> It might be worth looking into doing something similar to commit
> 0dc8c730, in addition to the optimistic spinning.

It is a good tunning for large machine. I just following what the commit
0dc8c730 done, give a RFC patch here. I tried it on my NHM EP machine. seems no
clear help on aim7. but maybe it is helpful on large machine.  :)

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

Conflicts:
	lib/rwsem.c