sched: LOAD_FREQ (4*HZ+61) avoids loadavg Moire
LOAD_FREQ is (5*HZ+1) to avoid high load average when idle:
http://kerneltrap.org/mailarchive/linux-kernel/2007/10/3/328568

I suggest (4*HZ+61) for a better distribution.

With some seconds based load (like SSL heartbeats)
and LOAD_FREQ at (5*HZ+1) I see Moire patterns like inverse sawtooth,
since 2 or 3 probes hit the jobs (load increases quickly),
followed by several probes missing it.

A 4.61 sec interval gives optimal distribution over when within a
second a probe is taken, as .61 is close to golden ratio phi 1.618...
(test in http://ripke.com/goldenratio.c).

12*4.61 = 55.32 secs is still close to a minute,
and 13*4.61=59.93 is even closer than the current 12*5.01=60.12
(with exponents EXP_x adjusted to a ratio of 13 instead of 12).

Thanks to Klaus Ripke http://ripke.com/loadavg/moire
https://lkml.org/lkml/2011/11/12/39
cpufreq: ondemand: Remove unnecessary synchronization attempt

Commit 1ce28d6b (ondemand: updated tune for hardware coordination)
brings in an attempt to synchronize expiry of per-cpu ondemand timer
at same time across all online cpus. This is meant to help systems
where "multiple cores share P-state via Hardware Coordination".

Synchronization is achieved by having timers expire when jiffy value
would be a perfect multiple of sampling window size. While such
synchronozation attemps are unnecessary on systems where cores don't
share P-states, it can hurt on power as cpus can now work off shorter
sampling windows (when percentage utilization over short window can be
observed to be high, causing frequency to be boosted).

Remove this unnecessary attempt to synchronize expiry of ondemand
timer across online cpus. A more acceptable solution could be to have
low-level architecture specific cpufreq driver indicate the need for
synchronization.

Change-Id: I6cb1cf3472ca106f029dc01248e0df7cfbb495b8
Signed-off-by: Srivatsa Vaddagiri <vatsa@codeaurora.org>
csdio: Remove the driver
The driver is a legacy driver that is not used any longer
and its implementation is neither correct nor compiles.

Change-Id: I9862c0f93ccad6079a616f6997987d4e187a137c
Signed-off-by: Hamad Kadmany <hkadmany@codeaurora.org>
block: introduce the BFQ-v7r2 I/O sched for 3.4

Add the BFQ-v7r2 I/O scheduler to 3.4.
The general structure is borrowed from CFQ, as much of the code for
handling I/O contexts. Over time, several useful features have been
ported from CFQ as well (details in the changelog in README.BFQ). A
(bfq_)queue is associated to each task doing I/O on a device, and each
time a scheduling decision has to be made a queue is selected and served
until it expires.

    - Slices are given in the service domain: tasks are assigned
      budgets, measured in number of sectors. Once got the disk, a task
      must however consume its assigned budget within a configurable
      maximum time (by default, the maximum possible value of the
      budgets is automatically computed to comply with this timeout).
      This allows the desired latency vs "throughput boosting" tradeoff
      to be set.

    - Budgets are scheduled according to a variant of WF2Q+, implemented
      using an augmented rb-tree to take eligibility into account while
      preserving an O(log N) overall complexity.

    - A low-latency tunable is provided; if enabled, both interactive
      and soft real-time applications are guaranteed a very low latency.

    - Latency guarantees are preserved also in the presence of NCQ.

    - Also with flash-based devices, a high throughput is achieved
      while still preserving latency guarantees.

    - BFQ features Early Queue Merge (EQM), a sort of fusion of the
      cooperating-queue-merging and the preemption mechanisms present
      in CFQ. EQM is in fact a unified mechanism that tries to get a
      sequential read pattern, and hence a high throughput, with any
      set of processes performing interleaved I/O over a contiguous
      sequence of sectors.

    - BFQ supports full hierarchical scheduling, exporting a cgroups
      interface.  Since each node has a full scheduler, each group can
      be assigned its own weight.

    - If the cgroups interface is not used, only I/O priorities can be
      assigned to processes, with ioprio values mapped to weights
      with the relation weight = IOPRIO_BE_NR - ioprio.

    - ioprio classes are served in strict priority order, i.e., lower
      priority queues are not served as long as there are higher
      priority queues.  Among queues in the same class the bandwidth is
      distributed in proportion to the weight of each queue. A very
      thin extra bandwidth is however guaranteed to the Idle class, to
      prevent it from starving.

Signed-off-by: Paolo Valente <paolo.valente@unimore.it>
Signed-off-by: Arianna Avanzini <avanzini.arianna@gmail.com>
block, bfq: add Early Queue Merge (EQM) to BFQ-v7r2 for 3.4.0

A set of processes may happen  to  perform interleaved reads, i.e., requests
whose union would give rise to a  sequential read  pattern.  There are two
typical  cases: in the first  case,   processes  read  fixed-size chunks of
data at a fixed distance from each other, while in the second case processes
may read variable-size chunks at  variable distances. The latter case occurs
for  example with  KVM, which  splits the  I/O generated  by the  guest into
multiple chunks,  and lets these chunks  be served by a  pool of cooperating
processes,  iteratively  assigning  the  next  chunk of  I/O  to  the first
available  process. CFQ  uses actual  queue merging  for the  first type of
rocesses, whereas it  uses preemption to get a sequential  read pattern out
of the read requests  performed by the second type of  processes. In the end
it uses  two different  mechanisms to  achieve the  same goal: boosting the
throughput with interleaved I/O.

This patch introduces  Early Queue Merge (EQM), a unified mechanism to get a
sequential  read pattern  with both  types of  processes. The  main idea is
checking newly arrived requests against the next request of the active queue
both in case of actual request insert and in case of request merge. By doing
so, both the types of processes can be handled by just merging their queues.
EQM is  then simpler and  more compact than the  pair of mechanisms used in
CFQ.

Finally, EQM  also preserves the  typical low-latency properties of BFQ, by
properly restoring the weight-raising state of  a queue when it gets back to
a non-merged state.

Signed-off-by: Mauro Andreolini <mauro.andreolini@unimore.it>
Signed-off-by: Arianna Avanzini <avanzini.arianna@gmail.com>
Reviewed-by: Paolo Valente <paolo.valente@unimore.it>
bfq-iosched: Tuning for SSD
bfq-iosched: Set bfq_back_penalty = 1
rtc: alarm: Add power-on alarm feature

Android does not support powering up of phone through alarm.
Adding shutdown hook in alarm driver which will set alarm while phone
is going down so as to power-up the phone after alarm expiration.

CRs-Fixed: 432312
Change-Id: I21786d264b93f7c0c660823a0a1a221c1b4df7b2
Signed-off-by: Ashay Jaiswal <ashayj@codeaurora.org>
rtc: alarm: Set power-on alarm 120 sec before actual alarm time

This will add extra buffer time for booting-up the device before
actual alarm expiration time.

Change-Id: I02cad84c394a6aab943fff37a1a0de56bb511f56
Signed-off-by: Mohit Aggarwal <maggarwa@codeaurora.org>
Signed-off-by: Ashay Jaiswal <ashayj@codeaurora.org>
kernel: alarm: :fix the BUG that device automatically powers on

The value of alarm.time is invalid if we get it by:
    memset(&alarm, 0, sizeof(alarm)).
So function of rtc_set_alarm aborts before it really calls into:
    rtc->ops->set_alarm.
Then we can`t disable the RTC alarm by that. The result is some
alarms enabled by alarm_suspend are not disabled correctly during
alarm_resume. And device will automatically power on.

CRs-fixed: 524051
Change-Id: Ibc99e62878d17ad4f50325630bf0862207e2cf3f
Signed-off-by: Figo Wang <figow@codeaurora.org>
kernel: alarm: add dedicated alarm type for poweroff alarm

Now we use type of RTC_WAKEUP for the poweroff alarm.
Actually lots of other applications also use this type.
But these applications never expect the device will
power on after it has been shut down. So we need to
add dedicated alarm type for the Deskclock or similar
applications.

CRs-fixed: 529674
Change-Id: I9b7911906446daa1aeb5835478c9837f8ef797f2
Signed-off-by: Figo Wang <figow@codeaurora.org>
kernel: alarm: Do not call rtc_alarm_irq_enable in IRQ Disabled context

Currently shutdown hook of alarm driver is calling
the rtc_alarm_irq_enable API in interrupts disabled
context. So fix the alarm_shutdown function to call
in API rtc_alarm_irq_enable in interrupt enabled context.

CRs-Fixed: 591790
Change-Id: Iebd82482be1dc95c6c978b617e1c18eb36e1b6eb
Signed-off-by: Prasad Sodagudi <psodagud@codeaurora.org>
arm: msm: add alarm reboot reason

Add alarm reboot reason for power off charging.

Change-Id: If94d0e4a7ec250cfaa61bf578cae9324db05d32c
Signed-off-by: Maria Yu <aiquny@codeaurora.org>
rtc: alarm: have dummy set_power_on_alarm function

When !CONFIG_RTC_CLASS we need to have a dummy set_power_on_alarm
function. Otherwise, it is easy to have build issues.

Change-Id: I39310241cc2e59f672964c8bc0ee4c3607aedf4e
Signed-off-by: Maria Yu <aiquny@codeaurora.org>
rtc: alarm: init power_on_alarm_lock mutex in alarmtimer_rtc_timer_init

Moved mutex_init of power_on_alarm_lock into alarmtimer_rtc_timer_init
so that if CONFIG_RTC_CLASS is not enabled, we dont try to initialize
the mutex.  This fixes a build issue when !CONFIG_RTC_CLASS

Change-Id: I270564b94fd54162aa177a2c9767655098662259
Signed-off-by: Kumar Gala <galak@codeaurora.org>