cpuidle: move field disable from per-driver to per-cpu

Andrew J.Schorr raises a question.  When he changes the disable setting on
a single CPU, it affects all the other CPUs.  Basically, currently, the
disable field is per-driver instead of per-cpu.  All the C states of the
same driver are shared by all CPU in the same machine.

The patch changes the `disable' field to per-cpu, so we could set this
separately for each cpu.

Signed-off-by: ShuoX Liu <shuox.liu@intel.com>
Reported-by: Andrew J.Schorr <aschorr@telemetry-investments.com>
Reviewed-by: Yanmin Zhang <yanmin_zhang@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Francisco Franco <franciscofranco.1990@gmail.com>
Signed-off-by: Hieu Phan <aznrice2k4@gmail.com>
msm: krait: export CPU type to userspace instead of having it buried on the kmsg log so that app developers can show it on their apps.

Signed-off-by: Francisco Franco <franciscofranco.1990@gmail.com>
Signed-off-by: Hieu Phan <aznrice2k4@gmail.com>
block: add runtime pm helpers

Add runtime pm helper functions:

void blk_pm_runtime_init(struct request_queue *q, struct device *dev)
  - Initialization function for drivers to call.

int blk_pre_runtime_suspend(struct request_queue *q)
  - If any requests are in the queue, mark last busy and return -EBUSY.
    Otherwise set q->rpm_status to RPM_SUSPENDING and return 0.

void blk_post_runtime_suspend(struct request_queue *q, int err)
  - If the suspend succeeded then set q->rpm_status to RPM_SUSPENDED.
    Otherwise set it to RPM_ACTIVE and mark last busy.

void blk_pre_runtime_resume(struct request_queue *q)
  - Set q->rpm_status to RPM_RESUMING.

void blk_post_runtime_resume(struct request_queue *q, int err)
  - If the resume succeeded then set q->rpm_status to RPM_ACTIVE
    and call __blk_run_queue, then mark last busy and autosuspend.
    Otherwise set q->rpm_status to RPM_SUSPENDED.

The idea and API is designed by Alan Stern and described here:
http://marc.info/?l=linux-scsi&m=133727953625963&w=2

Signed-off-by: Lin Ming <ming.m.lin@intel.com>
Signed-off-by: Aaron Lu <aaron.lu@intel.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Francisco Franco <franciscofranco.1990@gmail.com>
Signed-off-by: Francisco Franco <franciscofranco.1990@gmail.com>
Signed-off-by: Hieu Phan <aznrice2k4@gmail.com>

Conflicts:
	block/blk-core.c

Change-Id: I225336fbb29b03cd5f3881ada6c29637319a8520
block: implement runtime pm strategy

When a request is added:
    If device is suspended or is suspending and the request is not a
    PM request, resume the device.

When the last request finishes:
    Call pm_runtime_mark_last_busy().

When pick a request:
    If device is resuming/suspending, then only PM request is allowed
    to go.

The idea and API is designed by Alan Stern and described here:
http://marc.info/?l=linux-scsi&m=133727953625963&w=2

Signed-off-by: Lin Ming <ming.m.lin@intel.com>
Signed-off-by: Aaron Lu <aaron.lu@intel.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Francisco Franco <franciscofranco.1990@gmail.com>
Signed-off-by: Hieu Phan <aznrice2k4@gmail.com>
block: recursive merge requests

In a workload, thread 1 accesses a, a+2, ..., thread 2 accesses a+1, a+3,....
When the requests are flushed to queue, a and a+1 are merged to (a, a+1), a+2
and a+3 too to (a+2, a+3), but (a, a+1) and (a+2, a+3) aren't merged.

If we do recursive merge for such interleave access, some workloads throughput
get improvement. A recent worload I'm checking on is swap, below change
boostes the throughput around 5% ~ 10%.

Signed-off-by: Shaohua Li <shli@fusionio.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Francisco Franco <franciscofranco.1990@gmail.com>
Signed-off-by: Hieu Phan <aznrice2k4@gmail.com>
block: add a flag to identify PM request

Add a flag REQ_PM to identify the request is PM related, such requests
will not change the device request queue's runtime status. It is
intended to be used in driver's runtime PM callback, so that driver can
perform some IO to the device there with the queue's runtime status
unaffected. e.g. in SCSI disk's runtime suspend callback, the disk will
be put into stopped power state, and this require sending a command to
the device. Such command processing should not change the disk's runtime
status.

Signed-off-by: Lin Ming <ming.m.lin@intel.com>
Signed-off-by: Aaron Lu <aaron.lu@intel.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Francisco Franco <franciscofranco.1990@gmail.com>
Signed-off-by: Hieu Phan <aznrice2k4@gmail.com>