Move the code to check whether we've reached the host controller's limit
on the number of endpoints out of the two conditional statements, to
remove duplicate code.
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

The "port" field in xhci_virt_dev stores the port number associated with
one of the two xHCI split roothubs, not the unique port number the xHCI
hardware uses.  Since we'll need to store the real hardware port number in
future patches, rename this field to "fake_port".
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Some alternate interface settings have no endpoints associated with them.
This shows up in some USB webcams, particularly the Logitech HD 1080p,
which uses the uvcvideo driver.  If a driver switches between two alt
settings with no endpoints, there is no need to issue a configure endpoint
command, because there is no endpoint information to update.

The only time a configure endpoint command with just the add slot flag set
makes sense is when the driver is updating hub characteristics in the slot
context.  However, that code never calls xhci_check_bandwidth, so we
should be safe not issuing a command if only the slot context add flag is
set.
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This was done to resolve a conflict in this file:
	drivers/usb/host/xhci-ring.c
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

* 'pm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  ARM: mach-shmobile: sh7372 LCDC1 suspend fix V2 (incremental)
  OMAP: omap_device: only override _noirq methods, not normal suspend/resume
  PM / Runtime: Correct documentation of pm_runtime_irq_safe()
  ARM: mach-shmobile: sh7372 LCDC1 suspend fix
  sh-sci / PM: Use power.irq_safe
  PM: Use spinlock instead of mutex in clock management functions

* 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394/linux1394-2.6:
  firewire: sbp2: fix panic after rmmod with slow targets

This patch updates the recently submitted
"Associate the HDMI clock together with LCDC1 on sh7372"
to V2 with the following change:
 - Use lcdc1_device on AP4EVB to build properly.
Signed-off-by: NMagnus Damm <damm@opensource.se>
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>

The nfsservctl system call is now gone, so we should remove all
linkage for it.
Signed-off-by: NNeilBrown <neilb@suse.de>
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

* 'drm-intel-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/keithp/linux-2.6:
  drm/i915: Fix wrong initializer for "locked" variable in assert_panel_unlocked
  i915: do not setup intel_backlight twice

* 'usb-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb-2.6: (30 commits)
  USB: ftdi_sio: add Calao reference board support
  USB option driver K3765/K4505 avoid CDC_DATA interface
  USB: option: add YUGA device id to driver
  usb: s5p-ehci: fix a NULL pointer deference
  USB: EHCI: Do not rely on PORT_SUSPEND to stop USB resuming in ehci_bus_resume().
  USB option driver add PID of Huawei Vodafone K4605
  USB option driver add PID of Huawei Vodafone K3806
  xhci: Handle zero-length isochronous packets.
  USB: Avoid NULL pointer deref in usb_hcd_alloc_bandwidth.
  usb: musb: gadget: fix error path
  usb: gadget: f_phonet: unlock in error case
  usb: musb: blackfin: include prefetch head file
  usb: musb: tusb6010: fix compilation
  usb: gadget: renesas_usbhs: fix DMA build by including dma-mapping.h
  usb: musb: cppi: fix build errors due to DBG and missing musb variable
  usb: musb: ux500: replace missing DBG with dev_dbg
  usb: musb: ux500: set dma config for both src and dst
  usb: musb: fix oops on musb_gadget_pullup
  usb: host: ehci-omap: fix .remove and failure handling path of .probe(v1)
  usb: gadget: hid: don't STALL when processing a HID Descriptor request
  ...

* 'tty-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty-2.6:
  omap-serial: Allow IXON and IXOFF to be disabled.
  TTY: serial, document ignoring of uart->ops->startup error
  TTY: pty, fix pty counting
  8250: Fix race condition in serial8250_backup_timeout().
  serial/8250_pci: delete duplicate data definition
  8250_pci: add support for Rosewill RC-305 4x serial port card
  tty: Add "spi:" prefix for spi modalias
  atmel_serial: fix atmel_default_console_device
  serial: 8250_pnp: add Intermec CV60 touchscreen device
  drivers/serial/ucc_uart.c: Fix compiler warning
  pch_uart: Set PCIe bus number using probe parameter
  serial: samsung: Fix build error

Merge branch 'driver-core-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core-2.6

* 'driver-core-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core-2.6:
  drivers:misc: ti-st: fix unexpected UART close
  drivers:misc: ti-st: free skb on firmware download
  drivers:misc: ti-st: wait for completion at fail
  drivers:misc: ti-st: reinit completion before send
  drivers:misc: ti-st: fail-safe on wrong pkt type
  drivers:misc: ti-st: reinit completion on ver read
  drivers:misc:ti-st: platform hooks for chip states
  drivers:misc: ti-st: avoid a misleading dbg msg
  base/devres.c: quiet sparse noise about context imbalance
  pti: add missing CONFIG_PCI dependency
  drivers/base/devtmpfs.c: correct annotation of `setup_done'
  driver core: fix kernel-doc warning in platform.c
  firmware: fix google/gsmi.c build warning

* 'staging-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging-2.6:
  staging: tidspbridge: fix compilation on dsp clock functions
  staging: octeon-ethernet: Add missing #includes.
  Staging: zcache: signedness bug in tmem_get()
  staging: zcache: fix crash on high memory swap
  staging: brcm80211: SPARC build error fix
  staging: brcm80211: fix compile error on non-x86 archs since 3.0 kernel

Signed-off-by: NMichal Sroczynski <msroczyn@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

* 'for-linus' of git://git390.marist.edu/pub/scm/linux-2.6:
  [S390] memory hotplug: only unassign assigned increments
  [S390] Change default action from reipl to stop for on_restart
  [S390] arch/s390/kernel/ipl.c: correct error detection check
  [S390] drivers/s390/block/dasd_ioctl.c: add missing kfree
  [S390] nss,initrd: kernel image and initrd must be in different segments

According to the SFI specification irq number 0xFF means device has no
interrupt or interrupt attached via GPIO.

Currently, we don't handle this special case and set irq field in
*_board_info structs to 255.  It leads to confusion in some drivers.
Accelerometer driver tries to register interrupt 255, fails and prints
"Cannot get IRQ" to dmesg.
Signed-off-by: NKirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: NAlan Cox <alan@linux.intel.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound-2.6: (32 commits)
  ALSA: hda: Conexant: Allow different output types to share DAC
  ASoC: Correct element count for WM8996 sidetone HPF
  ASoC: Tegra: wm8903 machine driver: Drop Ventana support
  ASoC: Add samsung maintainer
  ASoC: Add Springbank I/O card to Speyside Kconfig
  ALSA: hda/conexant - Enable ADC-switching for auto-mic mode, too
  ALSA: hda - Fix double-headphone/speaker paths for Cxt auto-parser
  ALSA: hda - Update jack-sense info even when no automute is set
  ALSA: hda - Fix output-path initialization for Realtek auto-parser
  sound/soc/fsl/mpc8610_hpcd.c: add missing of_node_put
  sound/soc/fsl/p1022_ds.c: add missing of_node_put
  sound/soc/ep93xx/ep93xx-i2s.c: add missing kfree
  sound/soc/kirkwood/kirkwood-i2s.c: add missing kfree
  ASoC: soc-core: use GFP_KERNEL flag for kmalloc in snd_soc_cnew
  sound/soc/fsl/fsl_dma.c: add missing of_node_put
  ASoC: Clear completions from late WM8996 FLL lock IRQs
  ASoC: Clear any outstanding WM8962 FLL lock completions before waiting
  ASoC: Ensure we only run Speyside WM8962 bias level callbacks once
  ASoC: Fix configuration of WM8996 input enables
  ASoC: WM8996 record paths need AIFCLK
  ...

This bug causes the IECSR register clear failure.  In this case, the RETE
(retry error threshold exceeded) interrupt will be generated and cannot be
cleared.  So the related ISR may be called persistently.

The RETE bit in IECSR is cleared by writing a 1 to it.
Signed-off-by: NLiu Gang <Gang.Liu@freescale.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Kumar Gala <galak@kernel.crashing.org>
Cc: <stable@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The previous rtc-s3c had two issues related with its IRQ.

1. Users cannot open rtc multiple times because an open operation
   calls request_irq on the same IRQ.  (e.g., two user processes wants to
   open and read RTC time from rtc-s3c at the same time)

2. If alarm is set and no one has the rtc opened with filesystem
   (either the alarm is set by kernel/boot-loader or user set an alarm and
   closed rtc dev file), the pending bit is not cleared and no further
   interrupt is invoked.  When the alarm is used by the system itself such
   as a resume from suspend-to-RAM or other Low-power modes/idle, this is
   a critical issue.

This patch mitigates these issues by calling request_irq at probe and
free_irq at remove.
Signed-off-by: NMyungJoo Ham <myungjoo.ham@samsung.com>
Signed-off-by: NKyungmin Park <kyungmin.park@samsung.com>
Acked-by: NKukjin Kim <kgene.kim@samsung.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Changhwan Youn <chaos.youn@samsung.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

RTC-S3C used to print out debug messages incorrectly.  This patch
corrects incorrect outputs.  (undecoded bcd numbers, incorrectly decoded
register values)

This patch affects the pr-debug messages only.
Signed-off-by: NMyungJoo Ham <myungjoo.ham@samsung.com>
Signed-off-by: NKyungmin Park <kyungmin.park@samsung.com>
Acked-by: NKukjin Kim <kgene.kim@samsung.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Changhwan Youn <chaos.youn@samsung.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

bd2802_unregister_led_classdev() should unregister all registered
instances of led_classdev class that had registered by
bd2802_register_led_classdev().
Signed-off-by: NAxel Lin <axel.lin@gmail.com>
Acked-by: NKim Kyuwon <q1.kim@samsung.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Fix the following build errors:

  drivers/tty/serial/8250_early.c:160: error: 'BASE_BAUD' undeclared (first use in this function): 1 errors in 1 logs
  drivers/tty/serial/8250_early.c:37:24: error: asm/serial.h: No such file or directory: 1 errors in 1 logs

I am not sure if (1843200 / 16) is suitable for cris, but most other
arch's define it as this value.
Signed-off-by: NWANG Cong <xiyou.wangcong@gmail.com>
Cc: Mikael Starvik <starvik@axis.com>
Cc: Jesper Nilsson <jesper.nilsson@axis.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Since 43cc71ee ("platform: prefix MODALIAS with "platform:""), the
platform modalias is prefixed with "platform:".

This patch changes the MODULE_ALIAS to "platform:ab8500-pwm".
Signed-off-by: NAxel Lin <axel.lin@gmail.com>
Acked-by: NArun Murthy <arun.murthy@stericsson.com>
Cc: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Make sure we are passing the same cookie in all calls to
request_threaded_irq() and free_irq().
Signed-off-by: NAxel Lin <axel.lin@gmail.com>
Cc: Donggeun Kim <dg77.kim@samsung.com>
Cc: Minkyu Kang <mk7.kang@samsung.com>
Cc: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This is an i2c driver, not a platform driver, thus use "i2c" prefix for
the module alias.
Signed-off-by: NAxel Lin <axel.lin@gmail.com>
Acked-by: NMichael Hennerich <michael.hennerich@analog.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

We need a callback to do some things after pwm_enable, pwm_disable
and pwm_config.
Signed-off-by: NDilan Lee <dilee@nvidia.com>
Reviewed-by: NRobert Morell <rmorell@nvidia.com>
Reviewed-by: NArun Murthy <arun.murthy@stericsson.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Cc: Paul Mundt <lethal@linux-sh.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Commit 79dfdacc ("memcg: make oom_lock 0 and 1 based rather than
counter") tried to oom lock the hierarchy and roll back upon
encountering an already locked memcg.

The code is confused when it comes to detecting a locked memcg, though,
so it would fail and rollback after locking one memcg and encountering
an unlocked second one.

The result is that oom-locking hierarchies fails unconditionally and
that every oom killer invocation simply goes to sleep on the oom
waitqueue forever.  The tasks practically hang forever without anyone
intervening, possibly holding locks that trip up unrelated tasks, too.
Signed-off-by: NJohannes Weiner <jweiner@redhat.com>
Acked-by: NMichal Hocko <mhocko@suse.cz>
Acked-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add missing include of linux/module.h for drivers that use interfaces from
linux/module.h.  This patch fixes build errors.
Signed-off-by: NAxel Lin <axel.lin@gmail.com>
Cc: Jonathan McDowell <noodles@earth.li>
Acked-by: NKristoffer Ericson <kristoffer.ericson@gmail.com>
Cc: Magnus Damm <damm@opensource.se>
Cc: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

ep93xx_bl.c uses interfaces from linux/module.h, so it should include
that file.  This patch fixes build errors:

    CC [M]  drivers/video/backlight/ep93xx_bl.o
  drivers/video/backlight/ep93xx_bl.c:138: error: 'THIS_MODULE' undeclared here (not in a function)
  drivers/video/backlight/ep93xx_bl.c:158: error: expected declaration specifiers or '...' before string constant
  drivers/video/backlight/ep93xx_bl.c:158: warning: data definition has no type or storage class
  ...
Signed-off-by: NAxel Lin <axel.lin@gmail.com>
Acked-by: NH Hartley Sweeten <hsweeten@visionengravers.com>
Cc: Ryan Mallon <rmallon@gmail.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Replace/remove use of RIO v.1.2 registers/bits that are not
forward-compatible with newer versions of RapidIO specification.

RapidIO specification v.1.3 removed Write Port CSR, Doorbell CSR,
Mailbox CSR and Mailbox and Doorbell bits of the PEF CAR.

Use of removed (since RIO v.1.3) register bits affects users of
currently available 1.3 and 2.x compliant devices who may use not so
recent kernel versions.

Removing checks for unsupported bits makes corresponding routines
compatible with all versions of RapidIO specification.  Therefore,
backporting makes stable kernel versions compliant with RIO v.1.3 and
later as well.
Signed-off-by: NAlexandre Bounine <alexandre.bounine@idt.com>
Cc: Kumar Gala <galak@kernel.crashing.org>
Cc: Matt Porter <mporter@kernel.crashing.org>
Cc: Li Yang <leoli@freescale.com>
Cc: Thomas Moll <thomas.moll@sysgo.com>
Cc: Chul Kim <chul.kim@idt.com>
Cc: <stable@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

ZONE_CONGESTED is only cleared in kswapd, but pages can be freed in any
task.  It's possible ZONE_CONGESTED isn't cleared in some cases:

 1. the zone is already balanced just entering balance_pgdat() for
    order-0 because concurrent tasks free memory.  In this case, later
    check will skip the zone as it's balanced so the flag isn't cleared.

 2. high order balance fallbacks to order-0.  quote from Mel: At the
    end of balance_pgdat(), kswapd uses the following logic;

	If reclaiming at high order {
		for each zone {
			if all_unreclaimable
				skip
			if watermark is not met
				order = 0
				loop again

			/* watermark is met */
			clear congested
		}
	}

    i.e. it clears ZONE_CONGESTED if it the zone is balanced.  if not,
    it restarts balancing at order-0.  However, if the higher zones are
    balanced for order-0, kswapd will miss clearing ZONE_CONGESTED as
    that only happens after a zone is shrunk.  This can mean that
    wait_iff_congested() stalls unnecessarily.

This patch makes kswapd clear ZONE_CONGESTED during its initial
highmem->dma scan for zones that are already balanced.
Signed-off-by: NShaohua Li <shaohua.li@intel.com>
Acked-by: NMel Gorman <mgorman@suse.de>
Reviewed-by: NMinchan Kim <minchan.kim@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

It seems that 7bf69395 ("console: allow to retain boot console via
boot option keep_bootcon") doesn't always achieve what it aims, as when
printk_late_init() runs it unconditionally turns off all boot consoles.
With this patch, I am able to see more messages on the boot console in
KVM guests than I can without, when keep_bootcon is specified.

I think it is appropriate for the relevant -stable trees.  However, it's
more of an annoyance than a serious bug (ideally you don't need to keep
the boot console around as console handover should be working -- I was
encountering a situation where the console handover wasn't working and
not having the boot console available meant I couldn't see why).
Signed-off-by: NNishanth Aravamudan <nacc@us.ibm.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Greg KH <gregkh@suse.de>
Acked-by: NFabio M. Di Nitto <fdinitto@redhat.com>
Cc: <stable@kernel.org>		[2.6.39.x, 3.0.x]
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Paul said: I left Google at the end of last week - if it's not bouncing
already, menage@google.com isn't going to work for much longer.
Signed-off-by: NWanlong Gao <gaowanlong@cn.fujitsu.com>
Acked-by: NPaul Menage <paul@paulmenage.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

I get the below warning:

  BUG: using smp_processor_id() in preemptible [00000000] code: bash/746
  caller is native_sched_clock+0x37/0x6e
  Pid: 746, comm: bash Tainted: G        W   3.0.0+ #254
  Call Trace:
   [<ffffffff813435c6>] debug_smp_processor_id+0xc2/0xdc
   [<ffffffff8104158d>] native_sched_clock+0x37/0x6e
   [<ffffffff81116219>] try_to_free_mem_cgroup_pages+0x7d/0x270
   [<ffffffff8114f1f8>] mem_cgroup_force_empty+0x24b/0x27a
   [<ffffffff8114ff21>] ? sys_close+0x38/0x138
   [<ffffffff8114ff21>] ? sys_close+0x38/0x138
   [<ffffffff8114f257>] mem_cgroup_force_empty_write+0x17/0x19
   [<ffffffff810c72fb>] cgroup_file_write+0xa8/0xba
   [<ffffffff811522d2>] vfs_write+0xb3/0x138
   [<ffffffff8115241a>] sys_write+0x4a/0x71
   [<ffffffff8114ffd9>] ? sys_close+0xf0/0x138
   [<ffffffff8176deab>] system_call_fastpath+0x16/0x1b

sched_clock() can't be used with preempt enabled.  And we don't need
fast approach to get clock here, so let's use ktime API.
Signed-off-by: NShaohua Li <shaohua.li@intel.com>
Acked-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Tested-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The various basic memory allocation function return NULL, not an
ERR_PTR.

The semantic patch that makes this change is available in
scripts/coccinelle/null/eno.cocci.

More information about semantic patching is available at
http://coccinelle.lip6.fr/Signed-off-by: NThomas Meyer <thomas@m3y3r.de>
Cc: Niranjana Vishwanathapura <nvishwan@codeaurora.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The test for bad usage of min_t() and max_t() is missing the --ignore
type.  Add it.
Signed-off-by: NHui Zhu <teawater@gmail.com>
Signed-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Change to new git tree -
(git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git).
Signed-off-by: NRalf Thielow <ralf.thielow@googlemail.com>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Commit d1a05b69 ("memcg do not try to drain per-cpu caches without
pages") added a drain_local_stock() call to a preemptible section.

The draining task looks up the cpu-local stock twice to set the
draining-flag, then to drain the stock and clear the flag again.  If the
task is migrated to a different CPU in between, noone will clear the
flag on the first stock and it will be forever undrainable.  Its charge
can not be recovered and the cgroup can not be deleted anymore.

Properly pin the task to the executing CPU while draining stocks.
Signed-off-by: NJohannes Weiner <jweiner@redhat.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com
Acked-by: NMichal Hocko <mhocko@suse.cz>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>