Add SIO I/O scheduler

Change-Id: I3c4edf24c3747b488b8b6e457668a4b01edb727d
drivers: staging: Resync LMK with Google

Change-Id: If338822749261b5f396c5c713a38d88868eccead

Conflicts:
	drivers/staging/android/lowmemorykiller.c
vmscan: kswapd carefully call compaction

With CONFIG_COMPACTION enabled, kswapd does not try to free contiguous
free pages, even when it is woken for a higher order request.

This could be bad for eg.  jumbo frame network allocations, which are done
from interrupt context and cannot compact memory themselves.  Higher than
before allocation failure rates in the network receive path have been
observed in kernels with compaction enabled.

Teach kswapd to defragment the memory zones in a node, but only if
required and compaction is not deferred in a zone.

Change-Id: Ia4bb3034bbd209030bda7a6ebaa820091299f08d
[akpm@linux-foundation.org: reduce scope of zones_need_compaction]
Signed-off-by: Rik van Riel <riel@redhat.com>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Hillf Danton <dhillf@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
vmscan: only defer compaction for failed order and higher

Currently a failed order-9 (transparent hugepage) compaction can lead to
memory compaction being temporarily disabled for a memory zone.  Even if
we only need compaction for an order 2 allocation, eg.  for jumbo frames
networking.

The fix is relatively straightforward: keep track of the highest order at
which compaction is succeeding, and only defer compaction for orders at
which compaction is failing.

Change-Id: Ibf6cc80a83e22ba4e5e856b51d12b2e4c95b0698
Signed-off-by: Rik van Riel <riel@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Hillf Danton <dhillf@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
compact_pgdat: workaround lockdep warning in kswapd

I get this lockdep warning from swapping load on linux-next, due to
"vmscan: kswapd carefully call compaction".

=================================
[ INFO: inconsistent lock state ]
3.3.0-rc2-next-20120201 #5 Not tainted
---------------------------------
inconsistent {RECLAIM_FS-ON-W} -> {IN-RECLAIM_FS-W} usage.
kswapd0/28 [HC0[0]:SC0[0]:HE1:SE1] takes:
 (pcpu_alloc_mutex){+.+.?.}, at: [<ffffffff810d6684>] pcpu_alloc+0x67/0x325
{RECLAIM_FS-ON-W} state was registered at:
  [<ffffffff81099b75>] mark_held_locks+0xd7/0x103
  [<ffffffff8109a13c>] lockdep_trace_alloc+0x85/0x9e
  [<ffffffff810f6bdc>] __kmalloc+0x6c/0x14b
  [<ffffffff810d57fd>] pcpu_mem_zalloc+0x59/0x62
  [<ffffffff810d5d16>] pcpu_extend_area_map+0x26/0xb1
  [<ffffffff810d679f>] pcpu_alloc+0x182/0x325
  [<ffffffff810d694d>] __alloc_percpu+0xb/0xd
  [<ffffffff8142ebfd>] snmp_mib_init+0x1e/0x2e
  [<ffffffff8185cd8d>] ipv4_mib_init_net+0x7a/0x184
  [<ffffffff813dc963>] ops_init.clone.0+0x6b/0x73
  [<ffffffff813dc9cc>] register_pernet_operations+0x61/0xa0
  [<ffffffff813dca8e>] register_pernet_subsys+0x29/0x42
  [<ffffffff8185d044>] inet_init+0x1ad/0x252
  [<ffffffff810002e3>] do_one_initcall+0x7a/0x12f
  [<ffffffff81832bc5>] kernel_init+0x9d/0x11e
  [<ffffffff814e51e4>] kernel_thread_helper+0x4/0x10
irq event stamp: 656613
hardirqs last  enabled at (656613): [<ffffffff814e0ddc>] __mutex_unlock_slowpath+0x104/0x128
hardirqs last disabled at (656612): [<ffffffff814e0d34>] __mutex_unlock_slowpath+0x5c/0x128
softirqs last  enabled at (655568): [<ffffffff8105b4a5>] __do_softirq+0x120/0x136
softirqs last disabled at (654757): [<ffffffff814e52dc>] call_softirq+0x1c/0x30

other info that might help us debug this:
 Possible unsafe locking scenario:

       CPU0
       ----
  lock(pcpu_alloc_mutex);
  <Interrupt>
    lock(pcpu_alloc_mutex);

 *** DEADLOCK ***

no locks held by kswapd0/28.

stack backtrace:
Pid: 28, comm: kswapd0 Not tainted 3.3.0-rc2-next-20120201 #5
Call Trace:
 [<ffffffff810981f4>] print_usage_bug+0x1bf/0x1d0
 [<ffffffff81096c3e>] ? print_irq_inversion_bug+0x1d9/0x1d9
 [<ffffffff810982c0>] mark_lock_irq+0xbb/0x22e
 [<ffffffff810c5399>] ? free_hot_cold_page+0x13d/0x14f
 [<ffffffff81098684>] mark_lock+0x251/0x331
 [<ffffffff81098893>] mark_irqflags+0x12f/0x141
 [<ffffffff81098e32>] __lock_acquire+0x58d/0x753
 [<ffffffff810d6684>] ? pcpu_alloc+0x67/0x325
 [<ffffffff81099433>] lock_acquire+0x54/0x6a
 [<ffffffff810d6684>] ? pcpu_alloc+0x67/0x325
 [<ffffffff8107a5b8>] ? add_preempt_count+0xa9/0xae
 [<ffffffff814e0a21>] mutex_lock_nested+0x5e/0x315
 [<ffffffff810d6684>] ? pcpu_alloc+0x67/0x325
 [<ffffffff81098f81>] ? __lock_acquire+0x6dc/0x753
 [<ffffffff810c9fb0>] ? __pagevec_release+0x2c/0x2c
 [<ffffffff810d6684>] pcpu_alloc+0x67/0x325
 [<ffffffff810c9fb0>] ? __pagevec_release+0x2c/0x2c
 [<ffffffff810d694d>] __alloc_percpu+0xb/0xd
 [<ffffffff8106c35e>] schedule_on_each_cpu+0x23/0x110
 [<ffffffff810c9fcb>] lru_add_drain_all+0x10/0x12
 [<ffffffff810f126f>] __compact_pgdat+0x20/0x182
 [<ffffffff810f15c2>] compact_pgdat+0x27/0x29
 [<ffffffff810c306b>] ? zone_watermark_ok+0x1a/0x1c
 [<ffffffff810cdf6f>] balance_pgdat+0x732/0x751
 [<ffffffff810ce0ed>] kswapd+0x15f/0x178
 [<ffffffff810cdf8e>] ? balance_pgdat+0x751/0x751
 [<ffffffff8106fd11>] kthread+0x84/0x8c
 [<ffffffff814e51e4>] kernel_thread_helper+0x4/0x10
 [<ffffffff810787ed>] ? finish_task_switch+0x85/0xea
 [<ffffffff814e3861>] ? retint_restore_args+0xe/0xe
 [<ffffffff8106fc8d>] ? __init_kthread_worker+0x56/0x56
 [<ffffffff814e51e0>] ? gs_change+0xb/0xb

The RECLAIM_FS notations indicate that it's doing the GFP_FS checking that
Nick hacked into lockdep a while back: I think we're intended to read that
"<Interrupt>" in the DEADLOCK scenario as "<Direct reclaim>".

I'm hazy, I have not reached any conclusion as to whether it's right to
complain or not; but I believe it's uneasy about kswapd now doing the
mutex_lock(&pcpu_alloc_mutex) which lru_add_drain_all() entails.  Nor have
I reached any conclusion as to whether it's important for kswapd to do
that draining or not.

But so as not to get blocked on this, with lockdep disabled from giving
further reports, here's a patch which removes the lru_add_drain_all() from
kswapd's callpath (and calls it only once from compact_nodes(), instead of
once per node).

Signed-off-by: Hugh Dickins <hughd@google.com>
Cc: Rik van Riel <riel@redhat.com>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mm: compaction: make compact_control order signed

"order" is -1 when compacting via /proc/sys/vm/compact_memory.  Making
it unsigned causes a bug in __compact_pgdat() when we test:

	if (cc->order < 0 || !compaction_deferred(zone, cc->order))
		compact_zone(zone, cc);

[akpm@linux-foundation.org: make __compact_pgdat()'s comparison match other code sites]
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Minchan Kim <minchan@kernel.org>
Reviewed-by: Rik van Riel <riel@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
lowmemorykiller: Compact memory when killing processes

 * Memory compaction is never invoked on Android because we avoid swap
   and don't allocate huge pages. Fix it by invoking compaction from the LMK when
   a process is killed to reduce memory fragmentation.

Change-Id: I2bda790c2093e65fd6f43d52ea5149d6b57cb1e9
cpufreq: interactive: take idle notifications only when active

Register an idle notifier only when the governor is active.  Also
short-circuit work of idle end if the governor is not enabled.

Signed-off-by: Sam Leffler <sleffler@chromium.org>
Change-Id: I4cae36dd2e7389540d337d74745ffbaa0131870f
cpufreq: interactive: keep freezer happy when not current governor

Fix a problem where the hung task mechanism was deeming the interactive
clock boost thread as hung.  This was because the thread is created at
module init but never run/woken up until needed.  If the governor is not
being used this can be forever.  To workaround this explicitly wake up
the thread once all the necessary data structures are initialized.  The
latter required some minor code shuffle.

Signed-off-by: Sam Leffler <sleffler@chromium.org>
Change-Id: Ie2c058dd75dcb6460ea10e7ac997e46baf66b1fe
cpufreq: interactive: handle speed up and down in the realtime task

Not useful to have a separate, non-realtime workqueue for speed down
events, avoid priority inversion for speed up events.

Change-Id: Iddcd05545245c847aa1bbe0b8790092914c813d2
Signed-off-by: Todd Poynor <toddpoynor@google.com>
cpufreq: interactive: remove input_boost handling

Now handled in userspace Power HAL instead.

Change-Id: I78a4a2fd471308bfcd785bbefcc65fede27314cf
Signed-off-by: Todd Poynor <toddpoynor@google.com>
lowmemorykiller: Use asynchronous compaction

Change-Id: I6a65d06fc30b88fcedaaf1abf1855fdd19e3c912
i2c-algo-bit: Don't resched on clock stretching

Clock stretching is not supposed to last long, so asking to be
rescheduled while waiting for the clock line to be released by a slave
makes little sense. Odds are that the clock line will long have been
released when we run again, so we will have lost time and may even
get an SMBus timeout because of this.

So just busy-wait in that case. This also participates in the effort
to make i2c-algo-bit usable in contexts that can't sleep.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: Ben Skeggs <bskeggs@redhat.com>
staging: zcache: support multiple clients, prep for KVM and RAMster

This is version 3 of an update to zcache, incorporating feedback from the list.
This patch adds support to the in-kernel transcendent memory ("tmem") code
and the zcache driver for multiple clients, which will be needed for both
RAMster and KVM support.  It also adds additional tmem callbacks to support
RAMster and corresponding no-op stubs in the zcache driver.  In v2, I've
also taken the liberty of adding some additional sysfs variables to
both surface information and allow policy control.  Those experimenting
with zcache should find them useful.  V3 clarifies some code walking
and declaring arrays.

Signed-off-by: Dan Magenheimer <dan.magenheimer@oracle.com>

[v3: error27@gmail.com: fix array bounds/walking]
[v2: konrad.wilk@oracle.com: fix bools, add check for NULL, fix a comment]
[v2: sjenning@linux.vnet.ibm.com: add info/tunables for poor compression]
[v2: marcusklemm@googlemail.com: add tunable for max persistent pages]
Acked-by: Dan Carpenter <error27@gmail.com>
Cc: Nitin Gupta <ngupta@vflare.org>
Cc: linux-mm@kvack.org
Cc: kvm@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

staging: fix zcache building

zcache is only building tmem.c and not building zcache.c. To keep the
module name, zcache.c must be renamed if symbols from tmem.c are to
remain unexported.

Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@holoscopio.com>
Acked-by: Dan Magenheimer <dan.magenheimer@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

staging: zcache: module is GPL

This avoids tainting the kernel as if a proprietary module was loaded.
The kernel will still be tainted because this is a staging driver.

Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@holoscopio.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

staging: zcache: include module.h for MODULE_LICENSE

The oncoming cleanup of module.h usage requires the explicit inclusion
of module.h when it was otherwise being included indirectly. Otherwise,
building zcache will fail.

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@holoscopio.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

zcache: Use div_u64 for 64-bit division

xv_get_total_size_bytes returns a u64 value and it's used in a division.
This causes build failures in 32-bit architectures, as reported by Randy
Dunlap.

Reported-by: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@holoscopio.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Dan Magenheimer <dan.magenheimer@oracle.com>
Cc: Nitin Gupta <ngupta@vflare.org>
Acked-by: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

zcache: Fix build error when sysfs is not defined

Signed-off-by: Nitin Gupta <ngupta@vflare.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

staging: zcache: fix possible sleep under lock

zcache_new_pool() calls kmalloc() with GFP_KERNEL which has
__GFP_WAIT set.  However, zcache_new_pool() gets called on
a stack that holds the swap_lock spinlock, leading to a
possible sleep-with-lock situation. The lock is obtained
in enable_swap_info().

The patch replaces GFP_KERNEL with GFP_ATOMIC.

v2: replace with GFP_ATOMIC, not GFP_IOFS

Signed-off-by: Seth Jennings <sjenning@linux.vnet.ibm.com>
Acked-by: Dan Magenheimer <dan.magenheimer@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

staging: zcache: fix typos

The patch fixes two typos in zcache-main.c

Signed-off-by: Seth Jennings <sjenning@linux.vnet.ibm.com>
Acked-by: Dan Magenheimer <dan.magenheimer@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

staging: zcache: fix crash on high memory swap

zcache_put_page() was modified to pass page_address(page) instead of the
actual page structure. In combination with the function signature changes
to tmem_put() and zcache_pampd_create(), zcache_pampd_create() tries to
(re)derive the page structure from the virtual address.  However, if the
original page is a high memory page (or any unmapped page), this
virt_to_page() fails because the page_address() in zcache_put_page()
returned NULL.

This patch changes zcache_put_page() and zcache_get_page() to pass
the page structure instead of the page's virtual address, which
may or may not exist.

Signed-off-by: Seth Jennings <sjenning@linux.vnet.ibm.com>
Acked-by: Dan Magenheimer <dan.magenheimer@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

Staging: zcache: signedness bug in tmem_get()

"ret" needs to be signed for the error handling to work properly.

Signed-off-by: Dan Carpenter <error27@gmail.com>
Acked-by: Dan Magenheimer <dan.magenheimer@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

staging: zcache: fix cleancache crash

After commit c5f5c4db3938 ("staging: zcache: fix crash on high memory
swap") cleancache crashes on the first successful get.  This was caused
by a remaining virt_to_page() call in zcache_pampd_get_data_and_free()
that only gets run in the cleancache path.

The patch converts the virt_to_page() to struct page casting like was
done for other instances in c5f5c4db3938.

Signed-off-by: Seth Jennings <sjenning@linux.vnet.ibm.com>
Tested-By: Valdis Kletnieks <valdis.kletnieks@vt.edu>
Acked-by: Dan Magenheimer <dan.magenheimer@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

staging: zcache: fix crash on cpu remove

In the case that a cpu is taken offline before zcache_do_preload() is
ever called on the cpu, the per-cpu zcache_preloads structure will
be uninitialized.  In the CPU_DEAD case for zcache_cpu_notifier(),
kp->obj is not checked before calling kmem_cache_free() on it.
If it is NULL, a crash results.

This patch ensures that both kp->obj and kp->page are not NULL before
calling the respective free functions. In practice, just checking
one or the other should be sufficient since they are assigned together
in zcache_do_preload(), but I check both for safety.

Signed-off-by: Seth Jennings <sjenning@linux.vnet.ibm.com>
Acked-by: Dave Hansen <dave@linux.vnet.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

staging: zcache: reduce tmem bucket lock contention

tmem uses hash buckets each with their own rbtree and lock to
quickly lookup tmem objects.  tmem has TMEM_HASH_BUCKETS (256)
buckets per pool.  However, because of the way the tmem_oid is
generated for frontswap pages, only 16 unique tmem_oids are being
generated, resulting in only 16 of the 256 buckets being used.
This cause high lock contention for the per bucket locks.

This patch changes SWIZ_BITS to include more bits of the offset.
The result is that all 256 hash buckets are potentially used resulting in a
95% drop in hash bucket lock contention.

Signed-off-by: Seth Jennings <sjenning@linux.vnet.ibm.com>
Acked-by: Dan Magenheimer <dan.magenheimer@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

staging: zcache: remove zcache_direct_reclaim_lock

zcache_do_preload() currently does a spin_trylock() on the
zcache_direct_reclaim_lock. Holding this lock intends to prevent
shrink_zcache_memory() from evicting zbud pages as a result
of a preload.

However, it also prevents two threads from
executing zcache_do_preload() at the same time.  The first
thread will obtain the lock and the second thread's spin_trylock()
will fail (an aborted preload) causing the page to be either lost
(cleancache) or pushed out to the swap device (frontswap). It
also doesn't ensure that the call to shrink_zcache_memory() is
on the same thread as the call to zcache_do_preload().

Additional, there is no need for this mechanism because all
zcache_do_preload() calls that come down from cleancache already
have PF_MEMALLOC set in the process flags which prevents
direct reclaim in the memory manager. If the zcache_do_preload()
call is done from the frontswap path, we _want_ reclaim to be
done (which it isn't right now).

This patch removes the zcache_direct_reclaim_lock and related
statistics in zcache.

Based on v3.1-rc8

Signed-off-by: Seth Jennings <sjenning@linux.vnet.ibm.com>
Reviewed-by: Dave Hansen <dave@linux.vnet.ibm.com>
Acked-by: Dan Magenheimer <dan.magenheimer@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

Staging: zcache: Fix calls to obsolete function

Function "strict_strtol" replaced by "kstrtol" as suggested by the checkpatch script

Signed-off-by: Bernhard Heinloth <bernhard@heinloth.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

zcache: fix deadlock condition

I discovered this deadlock condition awhile ago working on RAMster
but it affects zcache as well.  The list spinlock must be
locked prior to the page spinlock and released after.  As
a result, the page copy must also be done while the locks are held.

Applies to 3.2.  Konrad, please push (via GregKH?)...
this is definitely a bug fix so need not be pushed during
a -rc0 window.

Signed-off-by: Dan Magenheimer <dan.magenheimer@oracle.com>
Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

zcache: Set SWIZ_BITS to 8 to reduce tmem bucket lock contention.

SWIZ_BITS > 8 results in a much larger number of "tmem_obj"
allocations, likely one per page-placed-in-frontswap.  The
tmem_obj is not huge (roughly 100 bytes), but it is large
enough to add a not-insignificant memory overhead to zcache.

The SWIZ_BITS=8  will get roughly the same lock contention
without the space wastage.

The effect of SWIZ_BITS can be thought of as "2^SWIZ_BITS is
the number of unique oids that be generated" (This concept is
limited to frontswap's use of tmem).

Acked-by: Seth Jennings <sjenning@linux.vnet.ibm.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

staging: zcache: fix serialization bug in zv stats

In a multithreaded workload, the zv_curr_dist_counts
and zv_cumul_dist_counts statistics are being corrupted
because the increments and decrements in zv_create
and zv_free are not atomic.

This patch converts these statistics and their corresponding
increments/decrements/reads to atomic operations.

Signed-off-by: Seth Jennings <sjenning@linux.vnet.ibm.com>
Acked-by: Dan Magenheimer <dan.magenheimer@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

staging: zcache: crypto API support

This patch allow zcache to use the crypto API for page compression.
It replaces the direct LZO compress/decompress calls with calls
into the crypto compression API. The compressor to be used is
specified in the kernel boot line with the zcache parameter like:
zcache=lzo or zcache=deflate.  If the specified compressor can't
be loaded, zcache uses lzo as the default compressor.

Signed-off-by: Seth Jennings <sjenning@linux.vnet.ibm.com>
Acked-by: Dan Magenheimer <dan.magenheimer@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

staging: zcache: avoid AB-BA deadlock condition

Commit 9256a47 fixed a deadlock condition, being sure that the buddy
list spinlock is always taken before the page spinlock.

However in zbud_free_and_delist() locking order is the opposite
(page lock -> list lock).

Possible unsafe locking scenario (reported by lockdep):

        CPU0                    CPU1
        ----                    ----
   lock(&(&zbpg->lock)->rlock);
                                lock(zbud_budlists_spinlock);
                                lock(&(&zbpg->lock)->rlock);
   lock(zbud_budlists_spinlock);

Fix by grabbing the locks in opposite order in zbud_free_and_delist().

Signed-off-by: Andrea Righi <andrea@betterlinux.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
cpufreq: Add a boostpulse interface to ondemand

For applications that require a one-shot increase in frequency,
the boostpulse interface would help to scale to max for the time
specified in boostime. This helps applications that currently
increases scaling_min_freq and resets later after a fixed duration.
Instead of changing scaling_min_freq applications can directly write
to boostpulse and governer resets during regular timer after the time
expires.

Change-Id: Ie5f490ff06b41364aa76dd468573433495da28a4
Signed-off-by: Narayanan Gopalakrishnan <nargop@codeaurora.org>

Conflicts:
	drivers/cpufreq/cpufreq_ondemand.c
drivers: cpufreq: Send a uevent when governor changes

 * Useful so userspace tools can reconfigure.

Change-Id: Ib423910b8b9ac791ebe81a75bf399f58272f64f2
s3cfb: Don't lock for vsync poll

Ioctl vsync polling runs in its own thread and will always hold
a lock on the framebuffer, only releasing on a vsync event, causing
microlags. Do not lock to prevent the issue from happening.

Not locking should not have any negative effect because the original
uevent code does not lock anyway.

From patch http://review.cyanogenmod.com/#/c/23634

Change-Id: I9fc56503f9952ae5dfc14eda64e0a43361ca2478
block: prepare I/O context for BFQ v5
block: cgroups kconfig build bits for BFQ v5
block: introduce the BFQ v5 I/O scheduler