defconfig: Change name

Signed-off-by: Kostas K <mpokwsths@gmail.com>
msm: hotplug: remove code related to cpu_killed

Earlier the completion event cpu_killed was used to synchronize
notify to hot plug framework that the CPU is dead. But now it is
replaced with another completion event cpu_died and it is placed
in the hotplug framework itself. So there is no need for a
platform to implement a completion event.

But in msm platform driver the completion event related code
was not removed with the changes in hotplug framework. This
patch removes the unused code.

Change-Id: I4418e5e397821e39a7b6a6efa997c4a866e9b46b
Signed-off-by: Venkat Devarasetty <vdevaras@codeaurora.org>
msm: hotplug: Block hotplug removal of CPU0

Hotplug removal of CPU0 is not currently supported. Attempts to
remove it may result in undefined behaviour. Explicitly block
any such attempts before other hotplug notifiers get the chance
to run by setting the notifier priority to INT_MAX.

Change-Id: I9e1f5b4a0db554295a097220417f2bdf4c690f5f
Signed-off-by: Matt Wagantall <mattw@codeaurora.org>
workqueue: don't use WQ_HIGHPRI for unbound workqueues

Unbound wqs aren't concurrency-managed and try to execute work items
as soon as possible.  This is currently achieved by implicitly setting
%WQ_HIGHPRI on all unbound workqueues; however, WQ_HIGHPRI
implementation is about to be restructured and this usage won't be
valid anymore.

Add an explicit chain-wakeup path for unbound workqueues in
process_one_work() instead of piggy backing on %WQ_HIGHPRI.

Change-Id: Iecd17a9935ee28f856d8b726bb4c296762922bed
Signed-off-by: Tejun Heo <tj@kernel.org>
Git-commit: 974271c485a4d8bb801decc616748f90aafb07ec
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
Signed-off-by: Matt Wagantall <mattw@codeaurora.org>
workqueue: factor out worker_pool from global_cwq

Move worklist and all worker management fields from global_cwq into
the new struct worker_pool.  worker_pool points back to the containing
gcwq.  worker and cpu_workqueue_struct are updated to point to
worker_pool instead of gcwq too.

This change is mechanical and doesn't introduce any functional
difference other than rearranging of fields and an added level of
indirection in some places.  This is to prepare for multiple pools per
gcwq.

v2: Comment typo fixes as suggested by Namhyung.

Change-Id: Iefae84798c2af580f425b92ed79117935d99f21f
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Git-commit: bd7bdd43dcb81bb08240b9401b36a104f77dc135
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
Signed-off-by: Matt Wagantall <mattw@codeaurora.org>
workqueue: use @pool instead of @gcwq or @cpu where applicable

Modify all functions which deal with per-pool properties to pass
around @pool instead of @gcwq or @cpu.

The changes in this patch are mechanical and don't caues any
functional difference.  This is to prepare for multiple pools per
gcwq.

Change-Id: I4be6727e1cce6f9aa2a0057b96bdc725c84f1ea8
Signed-off-by: Tejun Heo <tj@kernel.org>
Git-commit: 63d95a9150ee3bbd4117fcd609dee40313b454d9
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
Signed-off-by: Matt Wagantall <mattw@codeaurora.org>
workqueue: separate out worker_pool flags

GCWQ_MANAGE_WORKERS, GCWQ_MANAGING_WORKERS and GCWQ_HIGHPRI_PENDING
are per-pool properties.  Add worker_pool->flags and make the above
three flags per-pool flags.

The changes in this patch are mechanical and don't caues any
functional difference.  This is to prepare for multiple pools per
gcwq.

Change-Id: I1824fd1c509d8ac6b0619536621a22b15b316256
Signed-off-by: Tejun Heo <tj@kernel.org>
Git-commit: 11ebea50dbc1ade5994b2c838a096078d4c02399
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
Signed-off-by: Matt Wagantall <mattw@codeaurora.org>
workqueue: introduce NR_WORKER_POOLS and for_each_worker_pool()

Introduce NR_WORKER_POOLS and for_each_worker_pool() and convert code
paths which need to manipulate all pools in a gcwq to use them.
NR_WORKER_POOLS is currently one and for_each_worker_pool() iterates
over only @gcwq->pool.

Note that nr_running is per-pool property and converted to an array
with NR_WORKER_POOLS elements and renamed to pool_nr_running.  Note
that get_pool_nr_running() currently assumes 0 index.  The next patch
will make use of non-zero index.

The changes in this patch are mechanical and don't caues any
functional difference.  This is to prepare for multiple pools per
gcwq.

v2: nr_running indexing bug in get_pool_nr_running() fixed.

v3: Pointer to array is stupid.  Don't use it in get_pool_nr_running()
    as suggested by Linus.

Change-Id: I46e9488601d764d25e4a6c707de129ab68f7064c
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Fengguang Wu <fengguang.wu@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Git-commit: 4ce62e9e30cacc26885cab133ad1de358dd79f21
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
Signed-off-by: Matt Wagantall <mattw@codeaurora.org>
workqueue: reimplement WQ_HIGHPRI using a separate worker_pool

WQ_HIGHPRI was implemented by queueing highpri work items at the head
of the global worklist.  Other than queueing at the head, they weren't
handled differently; unfortunately, this could lead to execution
latency of a few seconds on heavily loaded systems.

Now that workqueue code has been updated to deal with multiple
worker_pools per global_cwq, this patch reimplements WQ_HIGHPRI using
a separate worker_pool.  NR_WORKER_POOLS is bumped to two and
gcwq->pools[0] is used for normal pri work items and ->pools[1] for
highpri.  Highpri workers get -20 nice level and has 'H' suffix in
their names.  Note that this change increases the number of kworkers
per cpu.

POOL_HIGHPRI_PENDING, pool_determine_ins_pos() and highpri chain
wakeup code in process_one_work() are no longer used and removed.

This allows proper prioritization of highpri work items and removes
high execution latency of highpri work items.

v2: nr_running indexing bug in get_pool_nr_running() fixed.

v3: Refreshed for the get_pool_nr_running() update in the previous
    patch.

Change-Id: Id843c0a425f51f84083786fbf413d999d35771b7
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Josh Hunt <joshhunt00@gmail.com>
LKML-Reference: <CAKA=qzaHqwZ8eqpLNFjxnO2fX-tgAOjmpvxgBFjv6dJeQaOW1w@mail.gmail.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Fengguang Wu <fengguang.wu@intel.com>
Git-commit: 3270476a6c0ce322354df8679652f060d66526dc
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
Signed-off-by: Matt Wagantall <mattw@codeaurora.org>
kernel/lib: add additional debug capabilites for data corruption

Data corruptions in the kernel often end up in system crashes that
are easier to debug closer to the time of detection. Specifically,
if we do not panic immediately after lock or list corruptions have been
detected, the problem context is lost in the ensuing system mayhem.
Add support for allowing system crash immediately after such corruptions
are detected. The CONFIG option controls the enabling/disabling of the
feature.

Change-Id: I9b2eb62da506a13007acff63e85e9515145909ff
Signed-off-by: Syed Rameez Mustafa <rameezmustafa@codeaurora.org>
sched: Fix select_idle_sibling() bouncing cow syndrome

If the previous CPU is cache affine and idle, select it.

The current implementation simply traverses the sd_llc domain,
taking the first idle CPU encountered, which walks buddy pairs
hand in hand over the package, inflicting excruciating pain.

1 tbench pair (worst case) in a 10 core + SMT package:

  pre   15.22 MB/sec 1 procs
  post 252.01 MB/sec 1 procs

Signed-off-by: Mike Galbraith <bitbucket@online.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1359371965.5783.127.camel@marge.simpson.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
sched: Implement smarter wake-affine logic

The wake-affine scheduler feature is currently always trying to pull
the wakee close to the waker. In theory this should be beneficial if
the waker's CPU caches hot data for the wakee, and it's also beneficial
in the extreme ping-pong high context switch rate case.

Testing shows it can benefit hackbench up to 15%.

However, the feature is somewhat blind, from which some workloads
such as pgbench suffer. It's also time-consuming algorithmically.

Testing shows it can damage pgbench up to 50% - far more than the
benefit it brings in the best case.

So wake-affine should be smarter and it should realize when to
stop its thankless effort at trying to find a suitable CPU to wake on.

This patch introduces 'wakee_flips', which will be increased each
time the task flips (switches) its wakee target.

So a high 'wakee_flips' value means the task has more than one
wakee, and the bigger the number, the higher the wakeup frequency.

Now when making the decision on whether to pull or not, pay attention to
the wakee with a high 'wakee_flips', pulling such a task may benefit
the wakee. Also imply that the waker will face cruel competition later,
it could be very cruel or very fast depends on the story behind
'wakee_flips', waker therefore suffers.

Furthermore, if waker also has a high 'wakee_flips', that implies that
multiple tasks rely on it, then waker's higher latency will damage all
of them, so pulling wakee seems to be a bad deal.

Thus, when 'waker->wakee_flips / wakee->wakee_flips' becomes
higher and higher, the cost of pulling seems to be worse and worse.

The patch therefore helps the wake-affine feature to stop its pulling
work when:

	wakee->wakee_flips > factor &&
	waker->wakee_flips > (factor * wakee->wakee_flips)

The 'factor' here is the number of CPUs in the current CPU's NUMA node,
so a bigger node will lead to more pulling since the trial becomes more
severe.

After applying the patch, pgbench shows up to 40% improvements and no regressions.

Tested with 12 cpu x86 server and tip 3.10.0-rc7.

The percentages in the final column highlight the areas with the biggest wins,
all other areas improved as well:

	pgbench		    base	smart

	| db_size | clients |  tps  |	|  tps  |
	+---------+---------+-------+   +-------+
	| 22 MB   |       1 | 10598 |   | 10796 |
	| 22 MB   |       2 | 21257 |   | 21336 |
	| 22 MB   |       4 | 41386 |   | 41622 |
	| 22 MB   |       8 | 51253 |   | 57932 |
	| 22 MB   |      12 | 48570 |   | 54000 |
	| 22 MB   |      16 | 46748 |   | 55982 | +19.75%
	| 22 MB   |      24 | 44346 |   | 55847 | +25.93%
	| 22 MB   |      32 | 43460 |   | 54614 | +25.66%
	| 7484 MB |       1 |  8951 |   |  9193 |
	| 7484 MB |       2 | 19233 |   | 19240 |
	| 7484 MB |       4 | 37239 |   | 37302 |
	| 7484 MB |       8 | 46087 |   | 50018 |
	| 7484 MB |      12 | 42054 |   | 48763 |
	| 7484 MB |      16 | 40765 |   | 51633 | +26.66%
	| 7484 MB |      24 | 37651 |   | 52377 | +39.11%
	| 7484 MB |      32 | 37056 |   | 51108 | +37.92%
	| 15 GB   |       1 |  8845 |   |  9104 |
	| 15 GB   |       2 | 19094 |   | 19162 |
	| 15 GB   |       4 | 36979 |   | 36983 |
	| 15 GB   |       8 | 46087 |   | 49977 |
	| 15 GB   |      12 | 41901 |   | 48591 |
	| 15 GB   |      16 | 40147 |   | 50651 | +26.16%
	| 15 GB   |      24 | 37250 |   | 52365 | +40.58%
	| 15 GB   |      32 | 36470 |   | 50015 | +37.14%

Signed-off-by: Michael Wang <wangyun@linux.vnet.ibm.com>
Cc: Mike Galbraith <efault@gmx.de>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/51D50057.9000809@linux.vnet.ibm.com
[ Improved the changelog. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
sched: Micro-optimize the smart wake-affine logic

Smart wake-affine is using node-size as the factor currently, but the overhead
of the mask operation is high.

Thus, this patch introduce the 'sd_llc_size' percpu variable, which will record
the highest cache-share domain size, and make it to be the new factor, in order
to reduce the overhead and make it more reasonable.

Tested-by: Davidlohr Bueso <davidlohr.bueso@hp.com>
Tested-by: Michael Wang <wangyun@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Michael Wang <wangyun@linux.vnet.ibm.com>
Cc: Mike Galbraith <efault@gmx.de>
Link: http://lkml.kernel.org/r/51D5008E.6030102@linux.vnet.ibm.com
[ Tidied up the changelog. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
sched: Fix clear NOHZ_BALANCE_KICK

I have faced a sequence where the Idle Load Balance was sometime not
triggered for a while on my platform, in the following scenario:

 CPU 0 and CPU 1 are running tasks and CPU 2 is idle

 CPU 1 kicks the Idle Load Balance
 CPU 1 selects CPU 2 as the new Idle Load Balancer
 CPU 2 sets NOHZ_BALANCE_KICK for CPU 2
 CPU 2 sends a reschedule IPI to CPU 2

 While CPU 3 wakes up, CPU 0 or CPU 1 migrates a waking up task A on CPU 2

 CPU 2 finally wakes up, runs task A and discards the Idle Load Balance
       task A quickly goes back to sleep (before a tick occurs on CPU 2)
 CPU 2 goes back to idle with NOHZ_BALANCE_KICK set

Whenever CPU 2 will be selected as the ILB, no reschedule IPI will be sent
because NOHZ_BALANCE_KICK is already set and no Idle Load Balance will be
performed.

We must wait for the sched softirq to be raised on CPU 2 thanks to another
part the kernel to come back to clear NOHZ_BALANCE_KICK.

The proposed solution clears NOHZ_BALANCE_KICK in schedule_ipi if
we can't raise the sched_softirq for the Idle Load Balance.

Change since V1:

- move the clear of NOHZ_BALANCE_KICK in got_nohz_idle_kick if the ILB
  can't run on this CPU (as suggested by Peter)

Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1370419991-13870-1-git-send-email-vincent.guittot@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Git-commit: 873b4c65b519fd769940eb281f77848227d4e5c1
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
[smuckle@codeaurora.org: minor merge resolution for 3.4 in scheduler_ipi()]
Signed-off-by: Steve Muckle <smuckle@codeaurora.org>
Change-Id: I3548612057cccc2ecc29429c129c44183083831f
sched: Unthrottle rt runqueues in __disable_runtime()

migrate_tasks() uses _pick_next_task_rt() to get tasks from the
real-time runqueues to be migrated. When rt_rq is throttled
_pick_next_task_rt() won't return anything, in which case
migrate_tasks() can't move all threads over and gets stuck in an
infinite loop.

Instead unthrottle rt runqueues before migrating tasks.

Additionally: move unthrottle_offline_cfs_rqs() to rq_offline_fair()

Signed-off-by: Peter Boonstoppel <pboonstoppel@nvidia.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Turner <pjt@google.com>
Link: http://lkml.kernel.org/r/5FBF8E85CA34454794F0F7ECBA79798F379D3648B7@HQMAIL04.nvidia.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
sched: Convert BUG_ON()s in try_to_wake_up_local() to WARN_ON_ONCE()s

try_to_wake_up_local() should only be invoked to wake up another
task in the same runqueue and BUG_ON()s are used to enforce the
rule. Missing try_to_wake_up_local() can stall workqueue
execution but such stalls are likely to be finite either by
another work item being queued or the one blocked getting
unblocked.  There's no reason to trigger BUG while holding rq
lock crashing the whole system.

Convert BUG_ON()s in try_to_wake_up_local() to WARN_ON_ONCE()s.

Change-Id: I75fdaaf4dcaefcf3893e0404d98c8aa91f89934d
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20130318192234.GD3042@htj.dyndns.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
Git-commit: 383efcd00053ec40023010ce5034bd702e7ab373
CRs-Fixed: 519942
Signed-off-by: Steve Muckle <smuckle@codeaurora.org>
sched: change WARN_ON_ONCE to WARN_ON in try_to_wake_up_local()

The WARN_ON_ONCE() calls at the beginning of try_to_wake_up_local()
were recently converted from BUG_ON() calls. If these hit it indicates
something is wrong and that may contribute to other system instability.
To eliminate the risk of an instance of one of these errors going
un-noticed because there was an earlier instance that occured long ago,
change to WARN_ON(). If there ever is a flood of these there are bigger
problems.

Change-Id: I392832e2b6ec24b3569b001b1af9ecd4ed6828e7
Signed-off-by: Steve Muckle <smuckle@codeaurora.org>
sched: re-calculate a cpu's next_balance point upon sched domain changes

Commit 55ddeb0f (sched: Reset rq->next_interval before going idle) reset
a cpu's rq->next_balance when pulled_task = 0, which will be true when
the cpu failed to pull any task, causing it go idle. However that patch
relied on next_balance being calculated as a result of traversing cpu's
sched domain hierarchy.

A cpu that is the only online cpu will however not be attached to any
sched domain hierarchy. When such a cpu calls into idle_balance(), we
will end up initializing next_balance to be 1sec away! Such a CPU will
defer load balance check for another 1sec, even though we may bring up
more cpus in the meantime requiring it to check for load imbalance more
frequently. This could then lead to increased scheduling latency for
some tasks.

This patch results in a cpu's next_balance being re-calculated when its
attaching to a new sched domain hierarchy.  This should let cpus call
load balance checks at the right time we expect them to!

Signed-off-by: Srivatsa Vaddagiri <vatsa@codeaurora.org>
(cherry picked from commit 91b609bdd91513c37c410ffef0204f8a0578e4f8)

Change-Id: Ib457f1a357aad26e49837a01311b73e22e0cc26f
Signed-off-by: Sridhar Nelloru <nellos@codeaurora.org>
sched: Mark schedule_io_timeout() with EXPORT_SYMBOL

Make schedule_io_timeout() visible to modules.

Change-Id: Ic0dedbad8a591a9a721f0d2e8f6c372ec75bc4b2
Signed-off-by: Jordan Crouse <jcrouse@codeaurora.org>
sched: Make sure to not re-read variables after validation

We could re-read rq->rt_avg after we validated it was smaller than
total, invalidating the check and resulting in an unintended negative.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: David Rientjes <rientjes@google.com>
Link: http://lkml.kernel.org/r/1337688268.9698.29.camel@twins
Signed-off-by: Ingo Molnar <mingo@kernel.org>
CRs-Fixed: 497236
Git-commit: b654f7de41b0e3903ee2b51d3b8db77fe52ce728
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
Signed-off-by: Srivatsa Vaddagiri <vatsa@codeaurora.org>
(cherry picked from commit fef154fa32c5d8ef992f11e11919495979970678)

Change-Id: Ieac7a10d9f4ceb701660f8055efd7a0ed5d939ca
Signed-off-by: Sridhar Nelloru <nellos@codeaurora.org>