workqueue: consider work function when searching for busy work items

To avoid executing the same work item concurrenlty, workqueue hashes
currently busy workers according to their current work items and looks
up the the table when it wants to execute a new work item.  If there
already is a worker which is executing the new work item, the new item
is queued to the found worker so that it gets executed only after the
current execution finishes.

Unfortunately, a work item may be freed while being executed and thus
recycled for different purposes.  If it gets recycled for a different
work item and queued while the previous execution is still in
progress, workqueue may make the new work item wait for the old one
although the two aren't really related in any way.

In extreme cases, this false dependency may lead to deadlock although
it's extremely unlikely given that there aren't too many self-freeing
work item users and they usually don't wait for other work items.

To alleviate the problem, record the current work function in each
busy worker and match it together with the work item address in
find_worker_executing_work().  While this isn't complete, it ensures
that unrelated work items don't interact with each other and in the
very unlikely case where a twisted wq user triggers it, it's always
onto itself making the culprit easy to spot.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Andrey Isakov <andy51@gmx.ru>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
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>
cpufreq: cpu-boost: Readd missing bits

The cpufreq patch series was somehow out of sync and
incomplete. Readd the unchanged policy update to source cpu
bit and readd the check for a possible corner case in
try_to_wake_up() that was already missing before.

Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
cpufreq: Break out early if freq equals to target_freq

Signed-off-by: Stratos Karafotis <stratosk@semaphore.gr>
Signed-off-by: franciscofranco <franciscofranco.1990@gmail.com>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
mmc: core: Exit clock scaling prior to removing the card

After removing the SD/MMC 'card' from the driver model we
are cancelling the pending clock scaling work which accesses
card->dev. This could cause NULL pointer issue as the card
is already removed.

Signed-off-by: Pratibhasagar V <pratibha@codeaurora.org>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
mmc: core: fix block request queue hang during data crc errors

When data CRC errors occur during write transactions, mmc
block layer queries the card for successful writes. If the card
reports bytes requested as bytes successfully written, the mmc
block layer will end the request with blk_end_request(). If there
is a following async request pending for execution, the request
is thrown away while handling CRC errors leading to hang in
request queue. The hang is visible when user issues a sync()
system call.

The sequence of events are as follows -

mmcqd -> fetch a request -> send it to host driver -> fetch another
request -> wait for previous request to complete -> previous request
is in error -> skip sending current request to host driver and
do error handling for previous request in error.

During the last step, after error handling is completed the mmc
block layer does not requeue the current request which is skipped
and hence the request is infinitely stuck in the driver.

Signed-off-by: Sujit Reddy Thumma <sthumma@codeaurora.org>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
mmc: card: quirk: disable cache for Hynix card

This change prevents enabling cache during card init for Hynix cards.
This change is workaround the problem of Hynix cards behavior for
adb reboot flow, when as a result of power cycle with cache enabled,
ext4 journal get aborted, because of meta data corruption.

Signed-off-by: Konstantin Dorfman <kdorfman@codeaurora.org>
Signed-off-by: Maya Erez <merez@codeaurora.org>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
mmc: core: Fix disabling of cache for Hynix cards

Commit f53e18514e11617c7111e0c8549a44077ab51e6c (mmc: card: quirk: disable cache for Hynix card)
claims to disable cache because of data corruption issues when cache
it is enabled. In reality, the patch allows enabling of cache during
card initialization but disallow flushing of cache during suspend or
file system sync operations. This is more dangerous than without
the commit. Move the fixups for disabling cache to mmc_fixups so as
to enable the quirk during initialization itself. Also, remove obvious
warnings everytime card is initialized during runtime resume.

Signed-off-by: Sujit Reddy Thumma <sthumma@codeaurora.org>
Signed-off-by: Konstantin Dorfman <kdorfman@codeaurora.org>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
mmc: core: get drive types supported by eMMC cards

Get the various drive types other than the default supported
by the card.

Signed-off-by: Krishna Konda <kkonda@codeaurora.org>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
prctl: adds PR_SET_TIMERSLACK_PID for setting timer slack of an arbitrary thread.

Second argument is similar to PR_SET_TIMERSLACK, if non-zero then the
slack is set to that value otherwise sets it to the default for the thread.

Takes PID of the thread as the third argument.

This allows power/performance management software to set timer slack for
other threads according to its policy for the thread (such as when the
thread is designated foreground vs. background activity)

Signed-off-by: Ruchi Kandoi <kandoiruchi@google.com>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
nf: IDLETIMER: time-stamp and suspend/resume handling.

Message notifications contains an additional timestamp field in nano seconds.
The expiry time for the timers are modified during suspend/resume.
If timer was supposed to expire while the system is suspended then a
notification is sent when it resumes with the timestamp of the scheduled expiry.

Removes the race condition for multiple work scheduled.

Signed-off-by: Ruchi Kandoi <kandoiruchi@google.com>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
cpufreq: interactive: Optimize sync_freq implementation

Don't let frequency drop below sync_freq if either load or
frequency among other cpus is above a certain threshold,
not necessarily both.

Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
msm: kgsl: Do not detect faults when GPU core is idle

Do not detect GPU faults when GPU hardware status is idle,
this leads to incorrect fault detection.

Signed-off-by: Tarun Karra <tkarra@codeaurora.org>
Signed-off-by: Hareesh Gundu <hareeshg@codeaurora.org>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
block: Switch from BFQ-v7r2 for 3.4.0 to BFQ-v7r3 for 3.4.0

. IMPROVEMENT: Improved throughput boosting with NCQ-capable HDDs and
  random workloads. The mechanism that further boosts throghput with
  these devices and workloads is activated only in the cases where it
  does not cause any violation of throughput-distribution and latency
  guarantees.
. IMPROVEMENT: Generalized the computation of the parameters of the
  low-latency heuristic for interactive applications, so as to fit also
  slower storage devices. The purpose of this improvement is to preserve
  low-latency guarantees for interactive applications also on slower
  devices, such as portable hard disks, multimedia and SD cards.
. BUGFIX: Re-added MODULE_LICENSE macro.
. CODE IMPROVEMENTS: Small code cleanups; introduced a coherent naming
  scheme for all identifiers related to weight raising; refactored and
  optimized a few hot paths.

Signed-off-by: Paolo Valente <paolo.valente@unimore.it>
Signed-off-by: Oleksandr Natalenko <oleksandr@natalenko.name>
Signed-off-by: Arianna Avanzini <avanzini.arianna@gmail.com>
Reported-by: Mikhail Akushsky <namelles.one@gmail.com>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
Power: Changes the permission to read only for sysfs file /sys/kernel/wakeup_reasons/last_resume_reason

Signed-off-by: Ruchi Kandoi <kandoiruchi@google.com>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
nf: Remove compilation error

Signed-off-by: Ruchi Kandoi <kandoiruchi@google.com>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
net: ipv4: current group_info should be put after using.

Plug a group_info refcount leak in ping_init.
group_info is only needed during initialization and
the code failed to release the reference on exit.
While here move grabbing the reference to a place
where it is actually needed.

Signed-off-by: Chuansheng Liu <chuansheng.liu@intel.com>
Signed-off-by: Zhang Dongxing <dongxing.zhang@intel.com>
Signed-off-by: xiaoming wang <xiaoming.wang@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>