lib: Proportions with flexible period

Implement code computing proportions of events of different type (like code in
lib/proportions.c) but allowing periods to have different lengths. This allows
us to have aging periods of fixed wallclock time which gives better proportion
estimates given the hugely varying throughput of different devices - previous
measuring of aging period by number of events has the problem that a reasonable
period length for a system with low-end USB stick is not a reasonable period
length for a system with high-end storage array resulting either in too slow
proportion updates or too fluctuating proportion updates.

Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
lib: Fix possible deadlock in flexible proportion code

When percpu counter function in fprop_new_period() is interrupted by an
interrupt while holding counter lock, it can cause deadlock when the
interrupt wants to take the lock as well. Fix the problem by disabling
interrupts when calling percpu counter functions.

Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
lib/flex_proportions.c: fix corruption of denominator in flexible proportions

When racing with CPU hotplug, percpu_counter_sum() can return negative
values for the number of observed events.

This confuses fprop_new_period(), which uses unsigned type and as a
result number of events is set to big *positive* number.  From that
moment on, things go pear shaped and can result e.g.  in division by
zero as denominator is later truncated to 32-bits.

This bug causes a divide-by-zero oops in bdi_dirty_limit() in Borislav's
3.6.0-rc6 based kernel.

Fix the issue by using a signed type in fprop_new_period().  That makes
us bail out from the function without doing anything (mistakenly)
thinking there are no events to age.  That makes aging somewhat
inaccurate but getting accurate data would be rather hard.

Signed-off-by: Jan Kara <jack@suse.cz>
Reported-by: Borislav Petkov <bp@amd64.org>
Reported-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
block: Convert BDI proportion calculations to flexible proportions

Convert calculations of proportion of writeback each bdi does to new flexible
proportion code. That allows us to use aging period of fixed wallclock time
which gives better proportion estimates given the hugely varying throughput of
different devices.

Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Luis Cruz <ljc2491@gmail.com>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
hammerhead: gpiomux: Fix observed current leak while boot up

Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
msm: thermal: Remove D tasks in kernel thermal monitor

Remove D tasks in kernel thermal monitor by moving
wait completion to its interruptible counterpart.
This will reduce the loadavg by 50 percent.

CRs-Fixed: 654474
Change-Id: I5fc82d83170b46393ac66ca354627341fc4b5296
Signed-off-by: Shiju Mathew <shijum@codeaurora.org>
msm: camera2: cpp: Reduce debug prints in cpp driver

The cpp driver had prints to monitor the status when node
is closed. This change makes them as pr_debug messages.

Change-Id: I8a78e6b38d7a702ed38f980d8fa658f50439da0f
Signed-off-by: Rajakumar Govindaram <rajakuma@codeaurora.org>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
msm: camera_v2: Create jpeg debugfs

This fixes kmsg errors because jpeg debugfs creation fails. The
device is online for only a few millisecs so the real use of the
interface is questionable, thus a full fix in ion with a camera
subdir not nessecary.

Change-Id: I0fe8eb9ca89b7b034c1e7c2f040730789f1a4efb

Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
build: Change it to my needs
build: b8