If we check the root_domain reference count we can see if its been
used or not, use this observation to simplify some of the return
paths.
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Nick Piggin <npiggin@kernel.dk>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/r/20110407122942.298339503@chello.nlSigned-off-by: NIngo Molnar <mingo@elte.hu>

Instead of relying on static allocations for the sched_domain and
sched_group trees, dynamically allocate and RCU free them.

Allocating this dynamically also allows for some build_sched_groups()
simplification since we can now (like with other simplifications) rely
on the sched_domain tree instead of hard-coded knowledge.

One tricky to note is that detach_destroy_domains() needs to hold
rcu_read_lock() over the entire tear-down, per-cpu is not sufficient
since that can lead to partial sched_group existance (could possibly
be solved by doing the tear-down backwards but this is much more
robust).

A concequence of the above is that we can no longer print the
sched_domain debug stuff from cpu_attach_domain() since that might now
run with preemption disabled (due to classic RCU etc.) and
sched_domain_debug() does some GFP_KERNEL allocations.

Another thing to note is that we now fully rely on normal RCU and not
RCU-sched, this is because with the new and exiting RCU flavours we
grew over the years BH doesn't necessarily hold off RCU-sched grace
periods (-rt is known to break this). This would in fact already cause
us grief since we do sched_domain/sched_group iterations from softirq
context.

This patch is somewhat larger than I would like it to be, but I didn't
find any means of shrinking/splitting this.
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Nick Piggin <npiggin@kernel.dk>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/r/20110407122942.245307941@chello.nlSigned-off-by: NIngo Molnar <mingo@elte.hu>

Again, instead of relying on knowing the possible domains and their
order, simply rely on the sched_domain tree and whatever domains are
present in there to initialize the sched_group cpu_power.

Note: we need to iterate the CPU mask backwards because of the
cpumask_first() condition for iterating up the tree. By iterating the
mask backwards we ensure all groups of a domain are set-up before
starting on the parent groups that rely on its children to be
completely done.
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Nick Piggin <npiggin@kernel.dk>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/r/20110407122942.187335414@chello.nlSigned-off-by: NIngo Molnar <mingo@elte.hu>

Instead of relying on knowing the build order and various CONFIG_
flags simply remember the bottom most sched_domain when we created the
domain hierarchy.
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Nick Piggin <npiggin@kernel.dk>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/r/20110407122942.134511046@chello.nlSigned-off-by: NIngo Molnar <mingo@elte.hu>

Instead of calling build_sched_groups() for each possible sched_domain
we might have created, note that we can simply iterate the
sched_domain tree and call it for each sched_domain present.
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Nick Piggin <npiggin@kernel.dk>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/r/20110407122942.077862519@chello.nlSigned-off-by: NIngo Molnar <mingo@elte.hu>

Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Nick Piggin <npiggin@kernel.dk>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/r/20110407122942.025636011@chello.nlSigned-off-by: NIngo Molnar <mingo@elte.hu>

The NODE sched_domain is 'special' in that it allocates sched_groups
per CPU, instead of sharing the sched_groups between all CPUs.

While this might have some benefits on large NUMA and avoid remote
memory accesses when iterating the sched_groups, this does break
current code that assumes sched_groups are shared between all
sched_domains (since the dynamic cpu_power patches).

So refactor the NODE groups to behave like all other groups.

(The ALLNODES domain again shared its groups across the CPUs for some
reason).

If someone does measure a performance decrease due to this change we
need to revisit this and come up with another way to have both dynamic
cpu_power and NUMA work nice together.
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Nick Piggin <npiggin@kernel.dk>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/r/20110407122941.978111700@chello.nlSigned-off-by: NIngo Molnar <mingo@elte.hu>

Notice that the mask being computed is the same as the domain span we
just computed. By using the domain_span we can avoid some mask
allocations and computations.
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Nick Piggin <npiggin@kernel.dk>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/r/20110407122941.925028189@chello.nlSigned-off-by: NIngo Molnar <mingo@elte.hu>

The code in update_group_power() does what init_sched_groups_power()
does and more, so remove the special init_ code and call the generic
code instead.

Also move the sd->span_weight initialization because
update_group_power() needs it.
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Nick Piggin <npiggin@kernel.dk>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/r/20110407122941.875856012@chello.nlSigned-off-by: NIngo Molnar <mingo@elte.hu>

Non weak static functions clearly are not arch specific, so remove the
arch_ prefix.
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Nick Piggin <npiggin@kernel.dk>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/r/20110407122941.820460566@chello.nlSigned-off-by: NIngo Molnar <mingo@elte.hu>

calc_delta_fair() checks NICE_0_LOAD already, delete duplicate check.

Signed-off-by: Shaohua Li<shaohua.li@intel.com>
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Link: http://lkml.kernel.org/r/1302238389.3981.92.camel@sli10-conroeSigned-off-by: NIngo Molnar <mingo@elte.hu>

The scheduler load balancer has specific code to deal with cases of
unbalanced system due to lots of unmovable tasks (for example because of
hard CPU affinity). In those situation, it excludes the busiest CPU that
has pinned tasks for load balance consideration such that it can perform
second 2nd load balance pass on the rest of the system.

This all works as designed if there is only one cgroup in the system.

However, when we have multiple cgroups, this logic has false positives and
triggers multiple load balance passes despite there are actually no pinned
tasks at all.

The reason it has false positives is that the all pinned logic is deep in
the lowest function of can_migrate_task() and is too low level:

load_balance_fair() iterates each task group and calls balance_tasks() to
migrate target load. Along the way, balance_tasks() will also set a
all_pinned variable. Given that task-groups are iterated, this all_pinned
variable is essentially the status of last group in the scanning process.
Task group can have number of reasons that no load being migrated, none
due to cpu affinity. However, this status bit is being propagated back up
to the higher level load_balance(), which incorrectly think that no tasks
were moved.  It kick off the all pinned logic and start multiple passes
attempt to move load onto puller CPU.

To fix this, move the all_pinned aggregation up at the iterator level.
This ensures that the status is aggregated over all task-groups, not just
last one in the list.
Signed-off-by: NKen Chen <kenchen@google.com>
Cc: stable@kernel.org
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/BANLkTi=ernzNawaR5tJZEsV_QVnfxqXmsQ@mail.gmail.comSigned-off-by: NIngo Molnar <mingo@elte.hu>

In function find_busiest_group(), the sched-domain avg_load isn't
calculated at all if there is a group imbalance within the domain. This
will cause erroneous imbalance calculation.

The reason is that calculate_imbalance() sees sds->avg_load = 0 and it
will dump entire sds->max_load into imbalance variable, which is used
later on to migrate entire load from busiest CPU to the puller CPU.

This has two really bad effect:

1. stampede of task migration, and they won't be able to break out
   of the bad state because of positive feedback loop: large load
   delta -> heavier load migration -> larger imbalance and the cycle
   goes on.

2. severe imbalance in CPU queue depth.  This causes really long
   scheduling latency blip which affects badly on application that
   has tight latency requirement.

The fix is to have kernel calculate domain avg_load in both cases. This
will ensure that imbalance calculation is always sensible and the target
is usually half way between busiest and puller CPU.
Signed-off-by: NKen Chen <kenchen@google.com>
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: <stable@kernel.org>
Link: http://lkml.kernel.org/r/20110408002322.3A0D812217F@elm.corp.google.comSigned-off-by: NIngo Molnar <mingo@elte.hu>

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound-2.6:
  ALSA: hda - Don't query connections for widgets have no connections
  ALSA: HDA: Fix single internal mic on ALC275 (Sony Vaio VPCSB1C5E)
  ALSA: hda - HDMI: Fix MCP7x audio infoframe checksums
  ALSA: usb-audio: define another USB ID for a buggy USB MIDI cable
  ALSA: HDA: Fix dock mic for Lenovo X220-tablet
  ASoC: format_register_str: Don't clip register values
  ASoC: PXA: Fix oops in __pxa2xx_pcm_prepare
  ASoC: zylonite: set .codec_dai_name in initializer

* git://git.infradead.org/mtd-2.6:
  mtd: atmel_nand: use CPU I/O when buffer is in vmalloc(ed) region
  mtd: atmel_nand: modify test case for using DMA operations
  mtd: atmel_nand: fix support for CPUs that do not support DMA access
  mtd: atmel_nand: trivial: change DMA usage information trace
  mtd: mtdswap: fix printk format warning

* 'bugfixes' of git://git.linux-nfs.org/projects/trondmy/nfs-2.6:
  NFS: Change initial mount authflavor only when server returns NFS4ERR_WRONGSEC
  NFS: Fix a signed vs. unsigned secinfo bug
  Revert "net/sunrpc: Use static const char arrays"

Fix erroneous syscall kernel-doc comments in kernel/signal.c.
Reported-by: NMatt Fleming <matt@console-pimps.org>
Signed-off-by: NRandy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

* 'for-linus' of git://git390.marist.edu/pub/scm/linux-2.6:
  [S390] compile fix for latest binutils
  [S390] cio: prevent purging of CCW devices in the online state
  [S390] qdio: fix init sequence
  [S390] Fix parameter passing for smp_switch_to_cpu()
  [S390] oprofile s390: prevent stack corruption

* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs-2.6:
  quota: Don't write quota info in dquot_commit()
  ext3: Fix writepage credits computation for ordered mode

* git://git.kernel.org/pub/scm/linux/kernel/git/wim/linux-2.6-watchdog:
  watchdog: mpc8xxx_wdt: fix build

Since 1c48a5c9 (dt: Eliminate of_platform_{,un}register_driver)
mpc8xxx_wdt no longer builds as it tries to refer to a 'match' variable
rather than ofdev->dev.of_match that it checks just before.
Signed-off-by: NPeter Korsgaard <jacmet@sunsite.dk>
Acked-by: NGrant Likely <grant.likely@secretlab.ca>
Signed-off-by: NWim Van Sebroeck <wim@iguana.be>

When attempting an initial mount, we should only attempt other
authflavors if AUTH_UNIX receives a NFS4ERR_WRONGSEC error.
This allows other errors to be passed back to userspace programs.
Signed-off-by: NBryan Schumaker <bjschuma@netapp.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Merge branch 'fbdev-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/lethal/fbdev-2.6

* 'fbdev-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/lethal/fbdev-2.6:
  efifb: Add override for 11" Macbook Air 3,1
  efifb: Support overriding fields FW tells us with the DMI data.
  fb: Reduce priority of resource conflict message
  savagefb: Remove obsolete else clause in savage_setup_i2c_bus
  savagefb: Set up I2C based on chip family instead of card id
  savagefb: Replace magic register address with define
  drivers/video/bfin-lq035q1-fb.c: introduce missing kfree
  video: s3c-fb: fix checkpatch errors and warning
  efifb: support AMD Radeon HD 6490
  s3fb: fix Virge/GX2
  fbcon: Remove unused 'display *p' variable from fb_flashcursor()
  fbdev: sh_mobile_lcdcfb: fix module lock acquisition
  fbdev: sh_mobile_lcdcfb: add blanking support
  viafb: initialize margins correct
  viafb: refresh rate bug collection
  sh: mach-ap325rxa: move backlight control code
  sh: mach-ecovec24: support for main lcd backlight

Merge branch 'rmobile-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/lethal/sh-2.6

* 'rmobile-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/lethal/sh-2.6:
  ARM: arch-shmobile: only run FSI init on respective boards
  ARM: arch-shmobile: only run HDMI init on respective boards
  ARM: mach-shmobile: Correctly check for CONFIG_MACH_MACKEREL

* 'sh-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/lethal/sh-2.6:
  sh: select ARCH_NO_SYSDEV_OPS.
  sh: fix build error in board-sh7757lcr.c
  sh: landisk: Remove whitespace
  sh: landisk: Remove mv_nr_irqs
  sh: sh-sci: Fix double initialization by serial_console_setup
  serial: sh-sci: prevent setup of uninitialized serial console
  dma: shdma: add checking the DMAOR_AE in sh_dmae_err

Merge branches 'x86-fixes-for-linus', 'sched-fixes-for-linus', 'timers-fixes-for-linus', 'irq-fixes-for-linus' and 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86-32, fpu: Fix FPU exception handling on non-SSE systems
  x86, hibernate: Initialize mmu_cr4_features during boot
  x86-32, NUMA: Fix ACPI NUMA init broken by recent x86-64 change
  x86: visws: Fixup irq overhaul fallout

* 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  sched: Clean up rebalance_domains() load-balance interval calculation

* 'timers-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86/mrst/vrtc: Fix boot crash in mrst_rtc_init()
  rtc, x86/mrst/vrtc: Fix boot crash in rtc_read_alarm()

* 'irq-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  genirq: Fix cpumask leak in __setup_irq()

* 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  perf probe: Fix listing incorrect line number with inline function
  perf probe: Fix to find recursively inlined function
  perf probe: Fix multiple --vars options behavior
  perf probe: Fix to remove redundant close
  perf probe: Fix to ensure function declared file

* 'staging-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging-2.6: (28 commits)
  staging: usbip: bugfix for isochronous packets and optimization
  staging: usbip: bugfix add number of packets for isochronous frames
  staging: usbip: bugfixes related to kthread conversion
  staging: usbip: fix shutdown problems.
  staging: hv: Fix GARP not sent after Quick Migration
  staging: IIO: IMU: ADIS16400: Avoid using printk facility directly
  staging: IIO: IMU: ADIS16400: Fix product ID check, skip embedded revision number
  staging: IIO: IMU: ADIS16400: Make sure only enabled scan_elements are pushed into the ring
  staging: IIO: IMU: ADIS16400: Fix addresses of GYRO and ACCEL calibration offset
  staging: IIO: IMU: ADIS16400: Add delay after self test
  staging: IIO: IMU: ADIS16400: Fix up SPI messages cs_change behavior
  staging/rtl81*: build as loadable modules only
  staging: brcm80211: removed 'is_amsdu causing toss' log spam
  staging: brcm80211: fix for 'Short CCK' log spam
  staging: brcm80211: fix for 'AC_BE txop..' logs spammed problem
  staging: memrar: remove driver from tree
  staging: sep: remove last memrar remnants
  staging: fix hv_mouse build, needs delay.h
  staging: fix olpc_dcon build errors
  staging: sm7xx: fixed defines
  ...

Fix up trivial conflict in drivers/staging/memrar/memrar_handler.c
(deleted vs trivial spelling fixes)

* 'kvm-updates/2.6.39' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  KVM: move and fix substitue search for missing CPUID entries
  KVM: fix XSAVE bit scanning
  KVM: Enable async page fault processing
  KVM: fix crash on irqfd deassign

* 'for-linus' of git://git.infradead.org/ubifs-2.6:
  UBI: do not select KALLSYMS_ALL
  UBI: do not compare array with NULL
  UBI: check if we are in RO mode in the erase routine
  UBIFS: fix debugging failure in dbg_check_space_info
  UBIFS: fix error path in dbg_debugfs_init_fs
  UBIFS: unify error path dbg_debugfs_init_fs
  UBIFS: do not select KALLSYMS_ALL
  UBIFS: fix assertion warnings
  UBIFS: fix oops on error path in read_pnode
  UBIFS: do not read flash unnecessarily

* 'for-linus2' of git://git.profusion.mobi/users/lucas/linux-2.6:
  Fix common misspellings

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/hid:
  HID: Add support for CH Pro Throttle
  HID: hid-magicmouse: Increase evdev buffer size
  HID: add FF support for Logitech G25/G27
  HID: roccat: Add support for wireless variant of Pyra
  HID: Fix typo Keyoutch -> Keytouch
  HID: add support for Skycable 0x3f07 wireless presenter

Fix build failure issue for hv_mouse
When build 2.6.39-rc1 kernel, it will be blocked at build hv_mouse.

  drivers/staging/hv/hv_mouse.c: In function ‘ReleaseInputDevice’:
  drivers/staging/hv/hv_mouse.c:293: error: implicit declaration of function ‘udelay’
Signed-off-by: NYouquan Song <youquan.song@intel.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The normal mmap paths all avoid creating a mapping where the pgoff
inside the mapping could wrap around due to overflow.  However, an
expanding mremap() can take such a non-wrapping mapping and make it
bigger and cause a wrapping condition.

Noticed by Robert Swiecki when running a system call fuzzer, where it
caused a BUG_ON() due to terminally confusing the vma_prio_tree code.  A
vma dumping patch by Hugh then pinpointed the crazy wrapped case.
Reported-and-tested-by: NRobert Swiecki <robert@swiecki.net>
Acked-by: NHugh Dickins <hughd@google.com>
Cc: stable@kernel.org
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Fixes the kernel warnings with IDT codecs like
    hda_codec: connection list not available for 0x1e
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

In cases where there is only one internal mic connected to ADC 0x11,
alc275_setup_dual_adc won't handle the case, so we need to add the
ADC node to the array of candidates.

Cc: stable@kernel.org
BugLink: http://bugs.launchpad.net/bugs/752792
Reported-by: Vincenzo Pii
Signed-off-by: NDavid Henningsson <david.henningsson@canonical.com>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

The MCP7x hardware computes the audio infoframe channel count
automatically, but requires the audio driver to set the audio
infoframe checksum manually via the Nv_VERB_SET_Info_Frame_Checksum
control verb.

When audio starts playing, nvhdmi_8ch_7x_pcm_prepare sets the checksum
to (0x71 - chan - chanmask).  For example, for 2ch audio, chan == 1
and chanmask == 0 so the checksum is set to 0x70.  When audio playback
finishes and the device is closed, nvhdmi_8ch_7x_pcm_close resets the
channel formats, causing the channel count to revert to 8ch.  Since
the checksum is not reset, the hardware starts generating audio
infoframes with invalid checksums.  This causes some displays to blank
the video.

Fix this by updating the checksum and channel mask when the device is
closed and also when it is first initialized.  In addition, make sure
that the channel mask is appropriate for an 8ch infoframe by setting
it to 0x13 (FL FR LFE FC RL RR RLC RRC).
Signed-off-by: NAaron Plattner <aplattner@nvidia.com>
Acked-by: NStephen Warren <swarren@nvidia.com>
Cc: <stable@kernel.org>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

The sfi_mrtc_array[] only gets initialized when the sfi mrtc
table is parsed, so the vrtc_paddr should be initalized after it
too.
Signed-off-by: NFeng Tang <feng.tang@intel.com>
Signed-off-by: NAlan Cox <alan@linux.intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/1302140389-27603-1-git-send-email-feng.tang@intel.comSigned-off-by: NIngo Molnar <mingo@elte.hu>

Commit f44f7f96 ("RTC: Initialize kernel state from RTC") caused a
boot regression on the MRST platform.

The reason is that rtc_device_register() calls rtc_read_alarm() after
that change, which function does not have all driver data set up yet.

The rtc-mrst driver needs to call dev_set_drvdata() before rtc_device_register()
gets called.
Signed-off-by: NFeng Tang <feng.tang@intel.com>
Signed-off-by: NAlan Cox <alan@linux.intel.com>
Acked-by: NJohn Stultz <john.stultz@linaro.org>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/1302140384-27571-1-git-send-email-feng.tang@intel.comSigned-off-by: NIngo Molnar <mingo@elte.hu>