mm: vmscan: clear kswapd's special reclaim powers before exiting

When kswapd exits, it can end up taking locks that were previously held
by allocating tasks while they waited for reclaim.  Lockdep currently
warns about this:

On Wed, May 28, 2014 at 06:06:34PM +0800, Gu Zheng wrote:
>  inconsistent {RECLAIM_FS-ON-W} -> {IN-RECLAIM_FS-R} usage.
>  kswapd2/1151 [HC0[0]:SC0[0]:HE1:SE1] takes:
>   (&sig->group_rwsem){+++++?}, at: exit_signals+0x24/0x130
>  {RECLAIM_FS-ON-W} state was registered at:
>     mark_held_locks+0xb9/0x140
>     lockdep_trace_alloc+0x7a/0xe0
>     kmem_cache_alloc_trace+0x37/0x240
>     flex_array_alloc+0x99/0x1a0
>     cgroup_attach_task+0x63/0x430
>     attach_task_by_pid+0x210/0x280
>     cgroup_procs_write+0x16/0x20
>     cgroup_file_write+0x120/0x2c0
>     vfs_write+0xc0/0x1f0
>     SyS_write+0x4c/0xa0
>     tracesys+0xdd/0xe2
>  irq event stamp: 49
>  hardirqs last  enabled at (49):  _raw_spin_unlock_irqrestore+0x36/0x70
>  hardirqs last disabled at (48):  _raw_spin_lock_irqsave+0x2b/0xa0
>  softirqs last  enabled at (0):  copy_process.part.24+0x627/0x15f0
>  softirqs last disabled at (0):            (null)
>
>  other info that might help us debug this:
>   Possible unsafe locking scenario:
>
>         CPU0
>         ----
>    lock(&sig->group_rwsem);
>    <Interrupt>
>      lock(&sig->group_rwsem);
>
>   *** DEADLOCK ***
>
>  no locks held by kswapd2/1151.
>
>  stack backtrace:
>  CPU: 30 PID: 1151 Comm: kswapd2 Not tainted 3.10.39+ #4
>  Call Trace:
>    dump_stack+0x19/0x1b
>    print_usage_bug+0x1f7/0x208
>    mark_lock+0x21d/0x2a0
>    __lock_acquire+0x52a/0xb60
>    lock_acquire+0xa2/0x140
>    down_read+0x51/0xa0
>    exit_signals+0x24/0x130
>    do_exit+0xb5/0xa50
>    kthread+0xdb/0x100
>    ret_from_fork+0x7c/0xb0

This is because the kswapd thread is still marked as a reclaimer at the
time of exit.  But because it is exiting, nobody is actually waiting on
it to make reclaim progress anymore, and it's nothing but a regular
thread at this point.  Be tidy and strip it of all its powers
(PF_MEMALLOC, PF_SWAPWRITE, PF_KSWAPD, and the lockdep reclaim state)
before returning from the thread function.

Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reported-by: Gu Zheng <guz.fnst@cn.fujitsu.com>
Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Cc: Tang Chen <tangchen@cn.fujitsu.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
slub: search partial list on numa_mem_id(), instead of numa_node_id()

Currently, if allocation constraint to node is NUMA_NO_NODE, we search a
partial slab on numa_node_id() node.  This doesn't work properly on a
system having memoryless nodes, since it can have no memory on that node
so there must be no partial slab on that node.

On that node, page allocation always falls back to numa_mem_id() first.
So searching a partial slab on numa_node_id() in that case is the proper
solution for the memoryless node case.

Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Acked-by: Nishanth Aravamudan <nacc@linux.vnet.ibm.com>
Acked-by: David Rientjes <rientjes@google.com>
Acked-by: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Wanpeng Li <liwanp@linux.vnet.ibm.com>
Cc: Han Pingtian <hanpt@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
fs/ceph: replace pr_warning by pr_warn

Update the last pr_warning callsites in fs branch

Signed-off-by: Fabian Frederick <fabf@skynet.be>
Cc: Sage Weil <sage@inktank.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
fs/ceph/debugfs.c: replace seq_printf by seq_puts

Replace seq_printf where possible.

Signed-off-by: Fabian Frederick <fabf@skynet.be>
Cc: Sage Weil <sage@inktank.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
drivers/rtc/interface.c: fix infinite loop in initializing the alarm

In __rtc_read_alarm(), if the alarm time retrieved by
rtc_read_alarm_internal() from the device contains invalid values (e.g.
month=2,mday=31) and the year not set (=-1), the initialization will
loop infinitely because the year-fixing loop expects the time being
invalid due to leap year.

Fix reduces the loop to the leap years and adds final validity check.

Signed-off-by: Ales Novak <alnovak@suse.cz>
Acked-by: Alessandro Zummo <a.zummo@towertech.it>
Reported-by: Jiri Bohac <jbohac@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Documentation/devicetree/bindings: add documentation for the APM X-Gene SoC RTC DTS binding

Signed-off-by: Rameshwar Prasad Sahu <rsahu@apm.com>
Signed-off-by: Loc Ho <lho@apm.com>
Cc: Jon Masters <jcm@redhat.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
drivers/rtc: add APM X-Gene SoC RTC driver

Add support for the APM X-Gene SoC RTC driver.

Signed-off-by: Rameshwar Prasad Sahu <rsahu@apm.com>
Signed-off-by: Loc Ho <lho@apm.com>
Cc: Jon Masters <jcm@redhat.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
arm64: add APM X-Gene SoC RTC DTS entry

This patch adds APM X-Gene SoC RTC DTS entry

Signed-off-by: Rameshwar Prasad Sahu <rsahu@apm.com>
Signed-off-by: Loc Ho <lho@apm.com>
Cc: Jon Masters <jcm@redhat.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
drivers/rtc/rtc-m41t80.c: remove DRV_VERSION macro

History is in git, no need for sperate versioning.  Also remove the
success printout, RTC core does it, too.

Signed-off-by: Wolfram Sang <wsa@sang-engineering.com>
Cc: Jingoo Han <jg1.han@samsung.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
drivers/rtc/rtc-m41t80.c: clean up error paths

There is no cleanup needed when something fails in probe, so no need for
goto.  Directly return when something fails.

Signed-off-by: Wolfram Sang <wsa@sang-engineering.com>
Cc: Jingoo Han <jg1.han@samsung.com>
Acked-by: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
drivers/rtc/rtc-m41t80.c: propagate error value from smbus functions

Don't replace the value we got from the I2C layer, just pass it on.

Signed-off-by: Wolfram Sang <wsa@sang-engineering.com>
Cc: Jingoo Han <jg1.han@samsung.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
drivers/rtc/rtc-m41t80.c: add support for MicroCrystal rv4162

Signed-off-by: Wolfram Sang <wsa@sang-engineering.com>
Cc: Jingoo Han <jg1.han@samsung.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
drivers/rtc/rtc-efi.c: avoid subtracting day twice when computing year days

Compared source code of rtc-lib.c::rtc_year_days() with
efirtc.c::rtc_year_days(), found the code in rtc-efi decreases value of
day twice when it computing year days.  rtc-lib.c::rtc_year_days() has
already decrease days and return the year days from 0 to 365.

Signed-off-by: Lee, Chun-Yi <jlee@suse.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
drivers/rtc/rtc-cmos.c: drivers/char/rtc.c features for DECstation support

This brings in drivers/char/rtc.c functionality required for DECstation
and, should the maintainers decide to switch, Alpha systems to use
rtc-cmos.

Specifically these features are made available:

* RTC iomem rather than x86/PCI port I/O mapping, controlled with the
  RTC_IOMAPPED macro as with the original driver.  The DS1287A chip in all
  DECstation systems is mapped in the host bus address space as a
  contiguous block of 64 32-bit words of which the least significant byte
  accesses the RTC chip for both reads and writes.  All the address and
  data window register accesses are made transparently by the chipset glue
  logic so that the device appears directly mapped on the host bus.

* A way to set the size of the address space explicitly with the
  newly-added `address_space' member of the platform part of the RTC
  device structure.  This avoids the unreliable heuristics that does not
  work in a setup where the RTC is not explicitly accessed with the usual
  address and data window register pair.

* The ability to use the RTC periodic interrupt as a system clock
  device, which is implemented by arch/mips/kernel/cevt-ds1287.c for
  DECstation systems and takes the RTC interrupt away from the RTC driver.
   Eventually hooking back to the clock device's interrupt handler should
  be possible for the purpose of the alarm clock and possibly also
  update-in-progress interrupt, but this is not done by this change.

  o To avoid interfering with the clock interrupt all the places where
    the RTC interrupt mask is fiddled with are only executed if and IRQ
    has been assigned to the RTC driver.

  o To avoid changing the clock setup Register A is not fiddled with
    if CMOS_RTC_FLAGS_NOFREQ is set in the newly-added `flags' member of
    the platform part of the RTC device structure.  Originally, in
    drivers/char/rtc.c, this was keyed with the absence of the RTC
    interrupt, just like the interrupt mask, but there only the periodic
    interrupt frequency is set, whereas rtc-cmos also sets the divider
    bits.  Therefore a new flag is introduced so that systems where the
    RTC interrupt is not usable rather than used as a system clock device
    can fully initialise the RTC.

* A small clean-up is made to the IRQ assignment code that makes the IRQ
  number hardcoded to -1 rather than arbitrary -ENXIO (or whatever error
  happens to be returned by platform_get_irq) where no IRQ has been
  assigned to the RTC driver (NO_IRQ might be another candidate, but it
  looks like this macro has inconsistent or missing definitions and
  limited use and might therefore be unsafe).

Verified to work correctly with a DECstation 5000/240 system.

[akpm@linux-foundation.org: fix weird code layout]
Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
arch/mips/dec: switch DECstation systems to rtc-cmos

This adds an RTC platform device for DECstation systems so that they can
use the rtc-cmos driver for their RTC device.

Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
drivers/rtc/rtc-88pm860x.c: use of_get_child_by_name()

Use of_get_child_by_name() to obtain reference to charger node instead of
of_find_node_by_name() which can walk outside of the parent node.

Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Acked-by: Jingoo Han <jg1.han@samsung.com>
Cc: Haojian Zhuang <haojian.zhuang@linaro.org>
Cc: Sachin Kamat <sachin.kamat@linaro.org>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
drivers/rtc/rtc-88pm860x.c: add missing of_node_put()

Add missing of_node_put() to decrement the reference count.

Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Acked-by: Jingoo Han <jg1.han@samsung.com>
Cc: Haojian Zhuang <haojian.zhuang@linaro.org>
Cc: Sachin Kamat <sachin.kamat@linaro.org>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
drivers/rtc/rtc-da9052.c: ALARM causes interrupt storm

Setting the alarm to a time not on a minute boundary results in repeated
interrupts being generated by the DA9052/3 PMIC device until the kernel
RTC core sees that the alarm has rung.  Sometimes the number and frequency
of interrupts can cause the kernel to disable the IRQ line used by the
DA9052/3 PMIC with disasterous consequences.  This patch fixes the
problem.

Even though the DA9052/3 PMIC is capable generating periodic interrupts,
ie TICKS, the method used to distinguish RTC_AF from RTC_PF events was
flawed and can not work in conjunction with the regmap_irq kernel core.
Thus that flawed detection has also been removed by the DA9052/3 PMIC RTC
driver's irq handler, so that it no longer reports the wrong type of event
to the kernel RTC core.

The internal static functions within the DA9052/3 PMIC RTC driver have
been changed to pass the 'da9052_rtc' structure instead of the 'da9052'
because there is no backwards pointer from the 'da9052' structure.

This patch fixes the three issues described above.  The first is serious
because usiing the RTC alarm set to a non minute boundary will eventually
cause all component drivers that depend on the interrupt line to fail.
The solution adopted is to round up to alarm time to the next highest
minute.

The second bug, reporting a RTC_PF event instead of an RTC_AF event turns
out to not matter with the current implementation of the kernel RTC core
as it seems to ignore the event type.  However, should that change in the
future it is better to fix the issue now and not have 'problems waiting to
happen'

The third set of changes are to make the da9052_rtc structure available to
all the local internal functions in the driver.  This was done during
testing so that diagnostic data could be stored there.  Should the
solution to the first issue be found not acceptable, then the alternative
of using the TICKS interrupt at the fixed one second interval in order to
step to the exact second of the requested alarm requires an extra (alarm
time) piece of data to be stored.  In devices that use the alarm function
to wake up from sleep, accuracy to the second will result in the device
being awake for up to nearly a minute longer than expected.

Signed-off-by: Anthony Olech <anthony.olech.opensource@diasemi.com>
Cc: David Dajun Chen <dchen@diasemi.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
rtc: rtc-ds1742: make of_device_id array const

Make of_device_id array const, because all OF functions handle it as
const.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
rtc: rtc-hym8563: make of_device_id array const

Make of_device_id array const, because all OF functions handle it as
const.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Acked-by: Heiko Stbner <heiko@sntech.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>