cpufreq: fix utilization statistics for sync cpus

If the cpus are using related_cpus policy, then the
current implementaion will overwrite the the calculated
load for every iteration in the for loop. Hence, mpdecision
will read incorrect value, if the cores are using related
cpus policy. With this change mpdecision will read the
sum of the loads of all cpu's, if related cpu policy is
used.

Change-Id: I242c8fe39fd75dc3e48750a5b78a5d218b536ddd
Signed-off-by: Narayanan Gopalakrishnan <nargop@codeaurora.org>
Signed-off-by: Shruthi Krishna <skrish@codeaurora.org>
cpufreq: notify avg load for short sampling_rate

If the sampling rate is less than 50ms reporting
the actual load may lead to poor decision making
at user space. So, for sampling rates less than 50ms
report the average of load across two samples.

Change-Id: I0d1cf00801732bee8e4380158d7e892758226594
Signed-off-by: Narayanan Gopalakrishnan <nargop@codeaurora.org>
cpufreq: Resolve CPUFREQ_NOTIFY issue

When the cpufreq_stat receives the frequency policy notification,
it checks if the frequency table and stats table are present for the cpu.
If both are present, it returns with -EBUSY error to the notification.
Due to this, none of the other registered modules receive this
notification.

If the stat table and sysfs nodes are already created, return 0 instead
of returning EBUSY error.

Change-Id: I1fd4a46e6a65edfc6253c4271288f10912ae2ad7
Signed-off-by: Archana Sathyakumar <asathyak@codeaurora.org>
sched/nohz: Correctly initialize 'next_balance' in 'nohz' idle balancer

The 'next_balance' field of 'nohz' idle balancer must be initialized
to jiffies. Since jiffies is initialized to negative 300 seconds the
'nohz' idle balancer does not run for the first 300s (5mins) after
bootup. If no new processes are spawed or no idle cycles happen, the
load on the cpus will remain unbalanced for that duration.

Signed-off-by: Diwakar Tundlam <dtundlam@nvidia.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1DD7BFEDD3147247B1355BEFEFE4665237994F30EF@HQMAIL04.nvidia.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>

[xqi@codeaurora.org merge into different file location in 3.0]
Change-Id: I42c41210babb0881150d28d11c2d3fce24fe3a9f
Signed-off-by: Xin Qi <xqi@codeaurora.org>
sched/nohz: Fix logic in nohz_kick_needed

Update the logic so that as long as rq->nr_running is greater than 1,
nohz_kick will be needed, regardless of whether the current CPU has
successfully competed for the first or second cpu spot

Previous logic has the corner case that if current CPU has r_running more than
1, and two other CPUs alreay hold first and econd cpu spot, but they don't
meeting kicking criterial (first cpu has nr_running 1, and second cpu doesn't
have any load), then nohz_kick will not be set correctly.

Change-Id: I30790f22df0a2e90899daa44c67757284dcca25d
Signed-off-by: Xin Qi <xqi@codeaurora.org>

Conflicts:
	kernel/sched_fair.c
sched/nohz: Fix logic in run_rebalance_domains

If triggered by nohz_balancer_kick, idle_at_tick is not updated
accordingly.  Update myself at this moment right before it is used

Change-Id: I20dd4314159e70f955ffe482160c8867c65c261e
Signed-off-by: Xin Qi <xqi@codeaurora.org>
sched/nohz: Fix logic in trigger_load_balance

Whether we need to kick nohz doesn't depend on current rq->next_balance,
meaning it doesn't depend on the check of previous if condition.

Change-Id: I566011d6341fa7a9a700c834f77e129043eaba11
Signed-off-by: Xin Qi <xqi@codeaurora.org>
sched: Fix select_fallback_rq() vs cpu_active/cpu_online

Commit 5fbd036b55 ("sched: Cleanup cpu_active madness"), which was
supposed to finally sort the cpu_active mess, instead uncovered more.

Since CPU_STARTING is ran before setting the cpu online, there's a
(small) window where the cpu has active,!online.

If during this time there's a wakeup of a task that used to reside on
that cpu select_task_rq() will use select_fallback_rq() to compute an
alternative cpu to run on since we find !online.

select_fallback_rq() however will compute the new cpu against
cpu_active, this means that it can return the same cpu it started out
with, the !online one, since that cpu is in fact marked active.

This results in us trying to scheduling a task on an offline cpu and
triggering a WARN in the IPI code.

The solution proposed by Chuansheng Liu of setting cpu_active in
set_cpu_online() is buggy, firstly not all archs actually use
set_cpu_online(), secondly, not all archs call set_cpu_online() with
IRQs disabled, this means we would introduce either the same race or
the race from fd8a7de17 ("x86: cpu-hotplug: Prevent softirq wakeup on
wrong CPU") -- albeit much narrower.

[ By setting online first and active later we have a window of
  online,!active, fresh and bound kthreads have task_cpu() of 0 and
  since cpu0 isn't in tsk_cpus_allowed() we end up in
  select_fallback_rq() which excludes !active, resulting in a reset
  of ->cpus_allowed and the thread running all over the place. ]

The solution is to re-work select_fallback_rq() to require active
_and_ online. This makes the active,!online case work as expected,
OTOH archs running CPU_STARTING after setting online are now
vulnerable to the issue from fd8a7de17 -- these are alpha and
blackfin.

Reported-by: Chuansheng Liu <chuansheng.liu@intel.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Frysinger <vapier@gentoo.org>
Cc: linux-alpha@vger.kernel.org
Link: http://lkml.kernel.org/n/tip-hubqk1i10o4dpvlm06gq7v6j@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

Conflicts:

	kernel/sched/core.c

Change-Id: Ib22f61c28494bcccc40f9f7fa3812c72e5528203
bdi: use deferable timer for sync_supers task

sync_supers task currently wakes up periodically for superblock
writeback. This hurts power on battery driven devices. This patch
turns this housekeeping timer into a deferable timer so that it
does not fire when system is really idle.

CRs-Fixed: 353700
Signed-off-by: Yong Wang <yong.y.wang@intel.com>
Signed-off-by: Xia Wu <xia.wu@intel.com>
Signed-off-by: Krishna Vanka <kvanka@codeaurora.org>
(cherry picked from commit f398f30d1f34632d3c96758b5b19e65b056af072)

Change-Id: I6ec6310d66c0d014adf0f41e75cd4c48c233f83d
Signed-off-by: Sridhar Gujje <sgujje@codeaurora.org>
ARM: Fix deadlock scenario with smp_send_stop()

If one process calls sys_reboot and that process then stops other
CPUs while those CPUs are within a spin_lock() region we can
potentially encounter a deadlock scenario like below.

CPU 0                   CPU 1
-----                   -----
                        spin_lock(my_lock)
smp_send_stop()
 send_IPI               handle_IPI()
                         disable_preemption/irqs
                          while(1);
 <PREEMPT>
spin_lock(my_lock) <--- Waits forever

We shouldn't attempt to run any other tasks after we send a stop
IPI to a CPU so disable preemption so that this task runs to
completion.

Change-Id: I528af0b4448433bd9d6ca12d6a0e2c422a55d4be
CRs-Fixed: 396169
Reported-by: Sundarajan Srinivasan <sundaraj@codeaurora.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Revert "Asynchronous I/O latency to a solid-state disk greatly increased"

This reverts commit e8fd1ab12b2980b6c86b4580b5bc03e8cfa1bf46.
bcmdhd: fix: wake each third DTIM when in suspend

From dhd_linux.c:
/* If DTIM skip is set up as default, force it to wake
 * each third DTIM for better power savings.  Note that
 * one side effect is a chance to miss BC/MC packet.
 */

The previous setting of bcn_li_dtim = 3 caused wake-up only on
each fourth DTIM, even though each third DTIM was targeted, as
indicated above.
Revert "ARMv7: Flush the vectors page using the base address"

This reverts commit d2e721a917171a1424b5f48d9bc84424b2e39f89.
version 0.3.25 exp