Add bunch of stuff for govs, hotplug, etc

Signed-off-by: MassStash <MassStash@gmail.com>
slub: fix a memory leak in get_partial_node()

In the case which is below,

1. acquire slab for cpu partial list
2. free object to it by remote cpu
3. page->freelist = t

then memory leak is occurred.

Change acquire_slab() not to zap freelist when it works for cpu partial list.
I think it is a sufficient solution for fixing a memory leak.

Below is output of 'slabinfo -r kmalloc-256'
when './perf stat -r 30 hackbench 50 process 4000 > /dev/null' is done.

***Vanilla***
Sizes (bytes)     Slabs              Debug                Memory
------------------------------------------------------------------------
Object :     256  Total  :     468   Sanity Checks : Off  Total: 3833856
SlabObj:     256  Full   :     111   Redzoning     : Off  Used : 2004992
SlabSiz:    8192  Partial:     302   Poisoning     : Off  Loss : 1828864
Loss   :       0  CpuSlab:      55   Tracking      : Off  Lalig:       0
Align  :       8  Objects:      32   Tracing       : Off  Lpadd:       0

***Patched***
Sizes (bytes)     Slabs              Debug                Memory
------------------------------------------------------------------------
Object :     256  Total  :     300   Sanity Checks : Off  Total: 2457600
SlabObj:     256  Full   :     204   Redzoning     : Off  Used : 2348800
SlabSiz:    8192  Partial:      33   Poisoning     : Off  Loss :  108800
Loss   :       0  CpuSlab:      63   Tracking      : Off  Lalig:       0
Align  :       8  Objects:      32   Tracing       : Off  Lpadd:       0

Total and loss number is the impact of this patch.

Cc: <stable@vger.kernel.org>
Acked-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Joonsoo Kim <js1304@gmail.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
Signed-off-by: franciscofranco <franciscofranco.1990@gmail.com>
sched: Fix memory leakage in build_sched_groups()

In build_sched_groups() we don't need to call get_group() for cpus
which are already covered in previous iterations. Calling get_group()
would mark the group used and eventually leak it since we wouldn't
connect it and not find it again to free it.

This will happen only in cases where sg->cpumask contained more than
one cpu (For any topology level). This patch would free sg's memory
for all cpus leaving the group leader as the group isn't marked used
now.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/7a61e955abdcbb1dfa9fe493f11a5ec53a11ddd3.1370948150.git.viresh.kumar@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: franciscofranco <franciscofranco.1990@gmail.com>
random: fix accounting race condition with lockless irq entropy_count update

commit 10b3a32d292c21ea5b3ad5ca5975e88bb20b8d68 upstream.

Commit 902c098a3663 ("random: use lockless techniques in the interrupt
path") turned IRQ path from being spinlock protected into lockless
cmpxchg-retry update.

That commit removed r->lock serialization between crediting entropy bits
from IRQ context and accounting when extracting entropy on userspace
read path, but didn't turn the r->entropy_count reads/updates in
account() to use cmpxchg as well.

It has been observed, that under certain circumstances this leads to
read() on /dev/urandom to return 0 (EOF), as r->entropy_count gets
corrupted and becomes negative, which in turn results in propagating 0
all the way from account() to the actual read() call.

Convert the accounting code to be the proper lockless counterpart of
what has been partially done by 902c098a3663.

Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Cc: Qiang Huang <h.huangqiang@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Signed-off-by: franciscofranco <franciscofranco.1990@gmail.com>
timer: Prevent overflow in apply_slack

commit 98a01e779f3c66b0b11cd7e64d531c0e41c95762 upstream.

On architectures with sizeof(int) < sizeof (long), the
computation of mask inside apply_slack() can be undefined if the
computed bit is > 32.

E.g. with: expires = 0xffffe6f5 and slack = 25, we get:

expires_limit = 0x20000000e
bit = 33
mask = (1 << 33) - 1  /* undefined */

On x86, mask becomes 1 and and the slack is not applied properly.
On s390, mask is -1, expires is set to 0 and the timer fires immediately.

Use 1UL << bit to solve that issue.

Suggested-by: Deborah Townsend <dstownse@us.ibm.com>
Signed-off-by: Jiri Bohac <jbohac@suse.cz>
Link: http://lkml.kernel.org/r/20140418152310.GA13654@midget.suse.cz
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: franciscofranco <franciscofranco.1990@gmail.com>
hrtimer: Set expiry time before switch_hrtimer_base()

commit 84ea7fe37908254c3bd90910921f6e1045c1747a upstream.

switch_hrtimer_base() calls hrtimer_check_target() which ensures that
we do not migrate a timer to a remote cpu if the timer expires before
the current programmed expiry time on that remote cpu.

But __hrtimer_start_range_ns() calls switch_hrtimer_base() before the
new expiry time is set. So the sanity check in hrtimer_check_target()
is operating on stale or even uninitialized data.

Update expiry time before calling switch_hrtimer_base().

[ tglx: Rewrote changelog once again ]

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Cc: linaro-kernel@lists.linaro.org
Cc: linaro-networking@linaro.org
Cc: fweisbec@gmail.com
Cc: arvind.chauhan@arm.com
Link: http://lkml.kernel.org/r/81999e148745fc51bbcd0615823fbab9b2e87e23.1399882253.git.viresh.kumar@linaro.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: franciscofranco <franciscofranco.1990@gmail.com>
percpu: make pcpu_alloc_chunk() use pcpu_mem_free() instead of kfree()

commit 5a838c3b60e3a36ade764cf7751b8f17d7c9c2da upstream.

pcpu_chunk_struct_size = sizeof(struct pcpu_chunk) +
	BITS_TO_LONGS(pcpu_unit_pages) * sizeof(unsigned long)

It hardly could be ever bigger than PAGE_SIZE even for large-scale machine,
but for consistency with its couterpart pcpu_mem_zalloc(),
use pcpu_mem_free() instead.

Commit b4916cb17c26 ("percpu: make pcpu_free_chunk() use
pcpu_mem_free() instead of kfree()") addressed this problem, but
missed this one.

tj: commit message updated

Signed-off-by: Jianyu Zhan <nasa4836@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Fixes: 099a19d91ca4 ("percpu: allow limited allocation before slab is online)
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: franciscofranco <franciscofranco.1990@gmail.com>
mm: make fixup_user_fault() check the vma access rights too

commit 1b17844b29ae042576bea588164f2f1e9590a8bc upstream.

fixup_user_fault() is used by the futex code when the direct user access
fails, and the futex code wants it to either map in the page in a usable
form or return an error.  It relied on handle_mm_fault() to map the
page, and correctly checked the error return from that, but while that
does map the page, it doesn't actually guarantee that the page will be
mapped with sufficient permissions to be then accessed.

So do the appropriate tests of the vma access rights by hand.

[ Side note: arguably handle_mm_fault() could just do that itself, but
  we have traditionally done it in the caller, because some callers -
  notably get_user_pages() - have been able to access pages even when
  they are mapped with PROT_NONE.  Maybe we should re-visit that design
  decision, but in the meantime this is the minimal patch. ]

Found by Dave Jones running his trinity tool.

Reported-by: Dave Jones <davej@redhat.com>
Acked-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: franciscofranco <franciscofranco.1990@gmail.com>
cpufreq: create a helper function to get CPU utilization. Picked from @stratosk

Signed-off-by: franciscofranco <franciscofranco.1990@gmail.com>
Signed-off-by: MassStash <MassStash@gmail.com>
cpufreq: export the cpu load across cores to the policy struct. On Performance governor let's emulate a constant 100% load (in this Kernel's case it will make all cores online, which is kinda the purpose of a performance governor isn't it?).

Signed-off-by: franciscofranco <franciscofranco.1990@gmail.com>
Signed-off-by: MassStash <MassStash@gmail.com>
cpufreq: Initial CPU utilization should be 0

Signed-off-by: Stratos Karafotis <stratosk@semaphore.gr>
Signed-off-by: franciscofranco <franciscofranco.1990@gmail.com>
msm: don't build RQ_STATS.

Signed-off-by: franciscofranco <franciscofranco.1990@gmail.com>
Signed-off-by: MassStash <MassStash@gmail.com>
sched: Remove get_online_cpus() usage

Remove get_online_cpus() usage from the scheduler; there's 4 sites that
use it:

 - sched_init_smp(); where its completely superfluous since we're in
   'early' boot and there simply cannot be any hotplugging.

 - sched_getaffinity(); we already take a raw spinlock to protect the
   task cpus_allowed mask, this disables preemption and therefore
   also stabilizes cpu_online_mask as that's modified using
   stop_machine. However switch to active mask for symmetry with
   sched_setaffinity()/set_cpus_allowed_ptr(). We guarantee active
   mask stability by inserting sync_rcu/sched() into _cpu_down.

 - sched_setaffinity(); we don't appear to need get_online_cpus()
   either, there's two sites where hotplug appears relevant:
    * cpuset_cpus_allowed(); for the !cpuset case we use possible_mask,
      for the cpuset case we hold task_lock, which is a spinlock and
      thus for mainline disables preemption (might cause pain on RT).
    * set_cpus_allowed_ptr(); Holds all scheduler locks and thus has
      preemption properly disabled; also it already deals with hotplug
      races explicitly where it releases them.

 - migrate_swap(); we can make stop_two_cpus() do the heavy lifting for
   us with a little trickery. By adding a sync_sched/rcu() after the
   CPU_DOWN_PREPARE notifier we can provide preempt/rcu guarantees for
   cpu_active_mask. Use these to validate that both our cpus are active
   when queueing the stop work before we queue the stop_machine works
   for take_cpu_down().

CRs-fixed: 647141
Change-Id: Id41e66659574f716de0e7c29f477e56a86db9404
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: "Srivatsa S. Bhat" <srivatsa.bhat@linux.vnet.ibm.com>
Cc: Paul McKenney <paulmck@linux.vnet.ibm.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Rik van Riel <riel@redhat.com>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Link: http://lkml.kernel.org/r/20131011123820.GV3081@twins.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Git-commit: 6acce3ef84520537f8a09a12c9ddbe814a584dd2
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
[kaushalk@codeaurora.org: get_online_cpus has only 3 sites of usage in
 kernel/sched/core.c of msm-3.10 so migrate_swap changes are not
 applicable here. stop_two_cpus related change is not applicable to
 msm-3.10, so skip it.]
Signed-off-by: Kaushal Kumar <kaushalk@codeaurora.org>

Signed-off-by: franciscofranco <franciscofranco.1990@gmail.com>
Signed-off-by: MassStash <MassStash@gmail.com>
sched: Fix endless sync_sched/rcu() loop inside _cpu_down()

Commit 6acce3ef8:

	sched: Remove get_online_cpus() usage

tries to do sync_sched/rcu() inside _cpu_down() but triggers:

	INFO: task swapper/0:1 blocked for more than 120 seconds.
	...
	[<ffffffff811263dc>] synchronize_rcu+0x2c/0x30
	[<ffffffff81d1bd82>] _cpu_down+0x2b2/0x340
	...

It was caused by that in the rcu boost case we rely on smpboot thread to
finish the rcu callback, which has already been parked before sync in here
and leads to the endless sync_sched/rcu().

This patch exchanges the sequence of smpboot_park_threads() and
sync_sched/rcu() to fix the bug.

CRs-fixed: 647141
Change-Id: Ia8b325d7c3c778f428d9fb51271977c849df32ad
Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Tested-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Michael Wang <wangyun@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/5282EDC0.6060003@linux.vnet.ibm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Git-commit: 106dd5afde3cd10db7e1370b6ddc77f0b2496a75
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
Signed-off-by: Kaushal Kumar <kaushalk@codeaurora.org>
Signed-off-by: franciscofranco <franciscofranco.1990@gmail.com>
Signed-off-by: MassStash <MassStash@gmail.com>
sched: Remove extra put_online_cpus() inside sched_setaffinity()

Commit 6acce3ef8:

	sched: Remove get_online_cpus() usage

has left one extra put_online_cpus() inside sched_setaffinity(),
remove it to fix the WARN:

   ------------[ cut here ]------------
   WARNING: CPU: 0 PID: 3166 at kernel/cpu.c:84 put_online_cpus+0x43/0x70()
   ...
   [<ffffffff810c3fef>] put_online_cpus+0x43/0x70 [
   [<ffffffff810efd59>] sched_setaffinity+0x7d/0x1f9 [
   ...

CRs-fixed: 647141
Change-Id: I33f799f30a963db3e9459832832e9c786931c8c2
Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Tested-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Michael Wang <wangyun@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/526DD0EE.1090309@linux.vnet.ibm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Git-commit: ac9ff7997b6f2b31949dcd2495ac671fd9ddc990
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
Signed-off-by: Kaushal Kumar <kaushalk@codeaurora.org>
Signed-off-by: franciscofranco <franciscofranco.1990@gmail.com>
Signed-off-by: MassStash <MassStash@gmail.com>
sched: Remove get_online_cpus() usage

Signed-off-by: franciscofranco <franciscofranco.1990@gmail.com>
Signed-off-by: MassStash <MassStash@gmail.com>
cpufreq: cpu-boost: Don't register for cpufreq notifiers too early

The cpufreq notifiers should be registered only after all the data
structures used in the notifier callbacks have been initialized. So, move
the cpufreq notifier registration to a later point in the init function.

Change-Id: I043ab5bc0ebb98164c40549fe151a8d801c8c186
Signed-off-by: Saravana Kannan <skannan@codeaurora.org>
Signed-off-by: MassStash <MassStash@gmail.com>
cpufreq: cpu-boost: merge missing bit of thread priority from https://github.com/myfluxi/kernel_msm/commit/9fbbbdd70ee1ef19e77eb72830cc53ae5c426515

Signed-off-by: franciscofranco <franciscofranco.1990@gmail.com>
Signed-off-by: MassStash <MassStash@gmail.com>
kthread: Fix the race condition when kthread is parked

While stressing the CPU hotplug path, sometimes we hit a problem
as shown below.

[57056.416774] ------------[ cut here ]------------
[57056.489232] ksoftirqd/1 (14): undefined instruction: pc=c01931e8
[57056.489245] Code: e594a000 eb085236 e15a0000 0a000000 (e7f001f2)
[57056.489259] ------------[ cut here ]------------
[57056.492840] kernel BUG at kernel/kernel/smpboot.c:134!
[57056.513236] Internal error: Oops - BUG: 0 [#1] PREEMPT SMP ARM
[57056.519055] Modules linked in: wlan(O) mhi(O)
[57056.523394] CPU: 0 PID: 14 Comm: ksoftirqd/1 Tainted: G        W  O 3.10.0-g3677c61-00008-g180c060 #1
[57056.532595] task: f0c8b000 ti: f0e78000 task.ti: f0e78000
[57056.537991] PC is at smpboot_thread_fn+0x124/0x218
[57056.542750] LR is at smpboot_thread_fn+0x11c/0x218
[57056.547528] pc : [<c01931e8>]    lr : [<c01931e0>]    psr: 200f0013
[57056.547528] sp : f0e79f30  ip : 00000000  fp : 00000000
[57056.558983] r10: 00000001  r9 : 00000000  r8 : f0e78000
[57056.564192] r7 : 00000001  r6 : c1195758  r5 : f0e78000  r4 : f0e5fd00
[57056.570701] r3 : 00000001  r2 : f0e79f20  r1 : 00000000  r0 : 00000000

This issue was always seen in the context of "ksoftirqd". It seems to
be happening because of a potential race condition in __kthread_parkme
where just after completing the parked completion, before the
ksoftirqd task has been scheduled again, it can go into running state.

Fix this by waiting for the task state to parked after waiting the
parked completion.

CRs-Fixed: 659674
Change-Id: If3f0e9b706eeb5d30d5a32f84378d35bb03fe794
Signed-off-by: Subbaraman Narayanamurthy <subbaram@codeaurora.org>
Signed-off-by: franciscofranco <franciscofranco.1990@gmail.com>
Signed-off-by: MassStash <MassStash@gmail.com>
msm: kgsl: Use high priority workqueue

Signed-off-by: franciscofranco <franciscofranco.1990@gmail.com>
Signed-off-by: MassStash <MassStash@gmail.com>