tmpfs: fix mempolicy object leaks
This patch fixes several mempolicy leaks in the tmpfs mount logic.
These leaks are slow - on the order of one object leaked per mount
attempt.

Leak 1 (umount doesn't free mpol allocated in mount):
    while true; do
        mount -t tmpfs -o mpol=interleave,size=100M nodev /mnt
        umount /mnt
    done

Leak 2 (errors parsing remount options will leak mpol):
    mount -t tmpfs -o size=100M nodev /mnt
    while true; do
        mount -o remount,mpol=interleave,size=x /mnt 2> /dev/null
    done
    umount /mnt

Leak 3 (multiple mpol per mount leak mpol):
    while true; do
        mount -t tmpfs -o mpol=interleave,mpol=interleave,size=100M nodev /mnt
        umount /mnt
    done

This patch fixes all of the above.  I could have broken the patch into
three pieces but is seemed easier to review as one.

Signed-off-by: Greg Thelen <gthelen@google.com>
modified for Mako kernel from LKML reference

Signed-off-by: faux123 <reioux@gmail.com>
lib/rwsem.c: steal writing sem for better performance fixed for 3.0.y

rwsem: steal writing sem for better performance
Commit 5a50508 changes to rwsem from mutex, caused aim7 fork_test
performance to dropped 50%. Yuanhan liu did an analysis, found it was
caused by strict sequential writing. Ingo suggest stealing sem writing from
front task in wait queue. https://lkml.org/lkml/2013/1/29/84

So does this patch.
In this patch, I just allow write stealing to happen when the first waiter
is also writer. The performance fully is now fully recovered.

Reported-by: lkp@linux.intel.com
Cc: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Alex Shi <alex.shi@intel.com>

lib/rwsem.c: fix compatibility issues with Linux 3.0.y
Signed-off-by: faux123 <reioux@gmail.com>
ARM: 7011/1: Add ARM cpu topology definition

The affinity between ARM processors is defined in the MPIDR register.
We can identify which processors are in the same cluster,
and which ones have performance interdependency. We can define the
cpu topology of ARM platform, that is then used by sched_mc and sched_smt.

The default state of sched_mc and sched_smt config is disable.
When enabled, the behavior of the scheduler can be modified with
sched_mc_power_savings and sched_smt_power_savings sysfs interfaces.

Changes since v4 :
*  Remove unnecessary parentheses and blank lines

Changes since v3 :
* Update the format of printk message
* Remove blank line

Changes since v2 :
* Update the commit message and some comments

Changes since v1 :
* Update the commit message
* Add read_cpuid_mpidr in arch/arm/include/asm/cputype.h
* Modify header of arch/arm/kernel/topology.c
* Modify tests and manipulation of MPIDR's bitfields
* Modify the place and dependancy of the config
* Modify Noop functions

Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>
Reviewed-by: Amit Kucheria <amit.kucheria@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
ARM: 7182/1: ARM cpu topology: fix warning

kernel/sched.c:7354:2: warning: initialization from incompatible pointer type

Align cpu_coregroup_mask prototype interface with sched_domain_mask_f typedef
use int cpu instead of unsigned int cpu

Cc: <stable@vger.kernel.org>
Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
ARM: topology: save cpu id of each core
ARM: topology: Update topology according to current sched_mc mode
ARM: topology: Add a cpu_power function
ARM: topology: Add a topology update notification
ARM: cpu topology: Add asym topology flag for using cpu0 1st

Modify the CPU sched_domain flags in powersave mode for using the cpu0 in ched_mc powersave mode

Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>
ARM: cpu topology: add debugfs
rwsem: R/W semaphores implemented using ARM atomic functions
stop the spam
WiFi driver update + Youtube HD bugfix
Added v2.5 defconfigs and updated build scripts