arm: tegra: hotplug: modify down_delay

Modified the hot-plug governor down_delay to be 500ms instead of 2s

Bug 958978

Change-Id: I55b5a4994f8e4564879cfd206fc683ff6f32d9ac
Signed-off-by: Wen Yi <wyi@nvidia.com>
(cherry picked from commit dd47739)
Reviewed-on: http://git-master/r/111640
Reviewed-by: Sai Gurrappadi <sgurrappadi@nvidia.com>
Tested-by: Sai Gurrappadi <sgurrappadi@nvidia.com>
Reviewed-by: Automatic_Commit_Validation_User
Reviewed-by: Peter Boonstoppel <pboonstoppel@nvidia.com>
Reviewed-by: Yu-Huan Hsu <yhsu@nvidia.com>
i2c: tegra: Fix i2c unknown interrupt issue

writes to modules on APB bus may complete out-of-order. need
to guarantee that the write is completed by reading it back.

read I2C_INT_STATUS back right after writing the current int status
in the isr to make sure the clear operation of I2C_INT_STATUS is
done before the interrupt is re-enabled.
the same also done for DVC_STATUS.

bug 980763

Change-Id: I34f18804d530ccadf561fe1736552b6a4dd6e4ce
Signed-off-by: Ken Chang <kenc@nvidia.com>
Reviewed-on: http://git-master/r/101925
Reviewed-by: Automatic_Commit_Validation_User
Reviewed-by: Bharat Nihalani <bnihalani@nvidia.com>
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.

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>
sched: don't call task_group() many times in set_task_rq()

It improves perfomance, especially if autogroup enabled.

The size of set_task_rq() was 0x180 and now it is 0xa0.

Signed-off-by: Andrew Vagin <avagin@openvz.org>
Signed-off-by: franciscofranco <franciscofranco.1990@gmail.com>