Since the irqtime accounting is using non-atomic u64 and can be read
from remote cpus (writes are strictly cpu local, reads are not) we
have to deal with observing partial updates.

When we do observe partial updates the clock movement (in particular,
->clock_task movement) will go funny (in either direction), a
subsequent clock update (observing the full update) will make it go
funny in the oposite direction.

Since we rely on these clocks to be strictly monotonic we cannot
suffer backwards motion. One possible solution would be to simply
ignore all backwards deltas, but that will lead to accounting
artefacts, most notable: clock_task + irq_time != clock, this
inaccuracy would end up in user visible stats.

Therefore serialize the reads using a seqcount.
Reviewed-by: Venkatesh Pallipadi <venki@google.com>
Reported-by: Mikael Pettersson <mikpe@it.uu.se>
Tested-by: Mikael Pettersson <mikpe@it.uu.se>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1292242434.6803.200.camel@twins>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Some ARM systems have a short sched_clock() [ which needs to be fixed
too ], but this exposed a bug in the irq_time code as well, it doesn't
deal with wraps at all.

Fix the irq_time code to deal with u64 wraps by re-writing the code to
only use delta increments, which avoids the whole issue.
Reviewed-by: Venkatesh Pallipadi <venki@google.com>
Reported-by: Mikael Pettersson <mikpe@it.uu.se>
Tested-by: Mikael Pettersson <mikpe@it.uu.se>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1292242433.6803.199.camel@twins>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

This fixes a bug as seen on 2.6.32 based kernels where timers got
enqueued on offline cpus.

If a cpu goes offline it might still have pending timers. These will
be migrated during CPU_DEAD handling after the cpu is offline.
However while the cpu is going offline it will schedule the idle task
which will then call tick_nohz_stop_sched_tick().

That function in turn will call get_next_timer_intterupt() to figure
out if the tick of the cpu can be stopped or not. If it turns out that
the next tick is just one jiffy off (delta_jiffies == 1)
tick_nohz_stop_sched_tick() incorrectly assumes that the tick should
not stop and takes an early exit and thus it won't update the load
balancer cpu.

Just afterwards the cpu will be killed and the load balancer cpu could
be the offline cpu.

On 2.6.32 based kernel get_nohz_load_balancer() gets called to decide
on which cpu a timer should be enqueued (see __mod_timer()). Which
leads to the possibility that timers get enqueued on an offline cpu.
These will never expire and can cause a system hang.

This has been observed 2.6.32 kernels. On current kernels
__mod_timer() uses get_nohz_timer_target() which doesn't have that
problem. However there might be other problems because of the too
early exit tick_nohz_stop_sched_tick() in case a cpu goes offline.

The easiest and probably safest fix seems to be to let
get_next_timer_interrupt() just lie and let it say there isn't any
pending timer if the current cpu is offline.

I also thought of moving migrate_[hr]timers() from CPU_DEAD to
CPU_DYING, but seeing that there already have been fixes at least in
the hrtimer code in this area I'm afraid that this could add new
subtle bugs.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20101201091109.GA8984@osiris.boeblingen.de.ibm.com>
Cc: stable@kernel.org
Signed-off-by: Ingo Molnar <mingo@elte.hu>

idle_balance() drops/retakes rq->lock, leaving the previous task
vulnerable to set_tsk_need_resched().  Clear it after we return
from balancing instead, and in setup_thread_stack() as well, so
no successfully descheduled or never scheduled task has it set.

Need resched confused the skip_clock_update logic, which assumes
that the next call to update_rq_clock() will come nearly immediately
after being set.  Make the optimization robust against the waking
a sleeper before it sucessfully deschedules case by checking that
the current task has not been dequeued before setting the flag,
since it is that useless clock update we're trying to save, and
clear unconditionally in schedule() proper instead of conditionally
in put_prev_task().
Signed-off-by: Mike Galbraith <efault@gmx.de>
Reported-by: Bjoern B. Brandenburg <bbb.lst@gmail.com>
Tested-by: Yong Zhang <yong.zhang0@gmail.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: stable@kernel.org
LKML-Reference: <1291802742.1417.9.camel@marge.simson.net>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

There's a long-running regression that proved difficult to fix and
which is hitting certain people and is rather annoying in its effects.

Damien reported that after 74f5187a (sched: Cure load average vs
NO_HZ woes) his load average is unnaturally high, he also noted that
even with that patch reverted the load avgerage numbers are not
correct.

The problem is that the previous patch only solved half the NO_HZ
problem, it addressed the part of going into NO_HZ mode, not of
comming out of NO_HZ mode. This patch implements that missing half.

When comming out of NO_HZ mode there are two important things to take
care of:

 - Folding the pending idle delta into the global active count.
 - Correctly aging the averages for the idle-duration.

So with this patch the NO_HZ interaction should be complete and
behaviour between CONFIG_NO_HZ=[yn] should be equivalent.

Furthermore, this patch slightly changes the load average computation
by adding a rounding term to the fixed point multiplication.
Reported-by: Damien Wyart <damien.wyart@free.fr>
Reported-by: Tim McGrath <tmhikaru@gmail.com>
Tested-by: Damien Wyart <damien.wyart@free.fr>
Tested-by: Orion Poplawski <orion@cora.nwra.com>
Tested-by: Kyle McMartin <kyle@mcmartin.ca>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: stable@kernel.org
Cc: Chase Douglas <chase.douglas@canonical.com>
LKML-Reference: <1291129145.32004.874.camel@laptop>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Merge branches 'x86-fixes-for-linus', 'perf-fixes-for-linus' and 'sched-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/pvclock: Zero last_value on resume

* 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  perf record: Fix eternal wait for stillborn child
  perf header: Don't assume there's no attr info if no sample ids is provided
  perf symbols: Figure out start address of kernel map from kallsyms
  perf symbols: Fix kallsyms kernel/module map splitting

* 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  nohz: Fix printk_needs_cpu() return value on offline cpus
  printk: Fix wake_up_klogd() vs cpu hotplug

* 'drm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/airlied/drm-2.6:
  drm/i915: i915 cannot provide switcher services.
  drm/radeon/kms: fix vram base calculation on rs780/rs880
  drm/radeon/kms: fix formatting of vram and gtt info
  drm/radeon/kms: forbid big bo allocation (fdo 31708) v3
  drm: Don't try and disable an encoder that was never enabled
  drm: Add missing drm_vblank_put() along queue vblank error path
  drm/i915/dp: Only apply the workaround if the select is still active
  drm/i915: Emit a request to clear a flushed and idle ring for unbusy bo
  drm/i915/lvds: Always restore panel-fitter when enabling the LVDS
  drm/i915/ringbuffer: Only print an error on the second attempt to reset head
  drm/i915: announce to userspace that the bsd ring is coherent
  agp/intel: Fix wrong kunmap in i830_cleanup()
  drm/i915: Factor in pixel-repeat in FDI M/N calculation
  drm/i915: Death to the unnecessary 64bit divide
  drm/i915: Clean conflicting modesetting registers upon init
  drm/i915: Apply a workaround for transitioning from DP on pipe B to HDMI.
  drm/i915: Always set the DP transcoder config to 8BPC.

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input:
  Input: wacom - add new Bamboo PT (0xdb)
  Input: add input driver for polled GPIO buttons
  Input: turbografx - fix reference counting
  Input: synaptics - fix handling of 2-button ClickPads
  Input: wacom - add IDs for two new Bamboo PTs
  Input: document struct input_absinfo
  Input: add keycodes for touchpad on/off keys
  Input: usbtouchscreen - add support for LG Flatron T1710B

it has a DSM but the switcher is done via WMI.
Signed-off-by: Dave Airlie <airlied@redhat.com>

Adds new Bamboo Pen & Touch model - Bamboo P & T Special Edition
Medium (CTH661/L; Product ID = 0xdb).
Tested-by: Tobias Verbeke <tobias.verbeke@gmail.com>
Signed-off-by: David Foley <favux.is@gmail.com>
Acked-by: Ping Cheng <pingc@wacom.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

* 'fixes/2637-rc5/s3c24xx' of git://git.fluff.org/bjdooks/linux:
  ARM: S3C24XX: Fix mess with gpio {set,get}_pull callbacks
  ARM: mini2440: Fix Kconfig to allow kernel to build
  ARM: S3C2412: Fix typo in CONFIG_CPU_S3C2412_ONLY definition
  ARM: S3C2443: Select properly ARM core type
  ARM: SMDK2416: Select MACH_SMDK, S3C_DEV_NAND, S3C_DEV_USB_HOST

Currently the {set,get}_pull callbacks of the s3c24xx_gpiocfg_default structure
are initalized via s3c_gpio_{get,set}pull_1up. This results in a linker
error when only CONFIG_CPU_S3C2442 is selected:

arch/arm/plat-s3c24xx/built-in.o:(.data+0x13f4): undefined reference to
`s3c_gpio_getpull_1up'
arch/arm/plat-s3c24xx/built-in.o:(.data+0x13f8): undefined reference to
`s3c_gpio_setpull_1up'

The s3c2442 has pulldowns instead of pullups compared to the s3c2440.
The method of controlling them is the same though.
So this patch modifies the existing s3c_gpio_{get,set}pull_1up helper functions
to take an additional parameter deciding whether the pin has a pullup or pulldown.
The s3c_gpio_{get,set}pull_1{down,up} functions then wrap that functions passing
either S3C_GPIO_PULL_UP or S3C_GPIO_PULL_DOWN.

Furthermore this patch sets up the s3c24xx_gpiocfg_default.{get,set}_pull fields
in the s3c244{0,2}_map_io function to the new pulldown helper functions.

Based on patch from "Lars-Peter Clausen" <lars@metafoo.de>
Signed-off-by: Vasily Khoruzhick <anarsoul@gmail.com>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>

Avoid overflowing a 32 bit value.
Signed-off-by: Alex Deucher <alexdeucher@gmail.com>
Cc: stable@kernel.org
Signed-off-by: Dave Airlie <airlied@redhat.com>

print the full 64 bit values.
Signed-off-by: Alex Deucher <alexdeucher@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

Forbid allocating buffer bigger than visible VRAM or GTT, also
properly set lpfn field.

v2 - use max macro
   - silence warning
v3 - don't explicitly set range limit
   - use min macro

Cc: stable <stable@kernel.org>
Signed-off-by: Jerome Glisse <jglisse@redhat.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

Prevents code that assumes that the encoder is active when asked to be
disabled from dying a horrible death.
Reported-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Dave Airlie <airlied@redhat.com>

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Kristian Høgsberg <krh@bitplanet.net>
Acked-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Dave Airlie <airlied@redhat.com>

Merge branch 'drm-intel-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/ickle/drm-intel into drm-fixes

As we may try to power down the link at various times, it is not
necessarily still coupled with an encoder and so we must be careful not
to depend upon an operation that is only valid when the link is still
attached to a pipe.

Fixes regression in 5bddd17f.
Reported-and-tested-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: stable@kernel.org [after applying 5bddd17f]

Fix the name of interrupt mask alteration function (ie the
local_change_intr_mask_level() fn) called in gdbstub to have an arch_
prefix to match the definition in asm/irqflags.h.
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

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

* 'irq-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  genirq: Fix incorrect proc spurious output

Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mjg59/platform-drivers-x86

* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mjg59/platform-drivers-x86:
  wmi: use memcmp instead of strncmp to compare GUIDs
  ACPI, hp-wmi: Fix memory leak in acpi query
  msi-wmi: fix semantically incorrect use of keycode instead of scancode
  msi-wmi: Add mute key support
  asus-laptop: add wimax and wwan support
  eeepc-wmi: fix compiler warning
  ibm_rtl: _RTL_ is not available in UEFI mode
  ibm_rtl: Loosen the DMI criteria to all IBM machines
  drivers/platform/x86/thinkpad_acpi.c: delete double assignment
  eeepc-wmi: add cpufv sysfs documentation
  toshiba_acpi.c: Add key_entry for a lone FN keypress
  ibm_rtl: fix printk format warning

* 'for-linus' of git://git390.marist.edu/pub/scm/linux-2.6:
  [S390] css: fix rsid evaluation for 2nd crw
  [S390] nohz/s390: fix arch_needs_cpu() return value on offline cpus

With the recent changes to remove the BKL a mutex was added to the
ioctl entry point for calls to the old ioctl interface. This mutex
needs to be removed because of the need for the expire ioctl to call
back to the daemon to perform a umount and receive a completion
status (via another ioctl).

This should be fine as the new ioctl interface uses much of the same
code and it has been used without a mutex for around a year without
issue, as was the original intention.

Ref: Bugzilla bug 23142
Signed-off-by: Ian Kent <raven@themaw.net>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

In order for bos to retire eventually, a request must be sent down the
ring. This is expected, for example, by occlusion queries for which mesa
will wait upon (whilst running glean) before issuing more batches and so
the normal activity upon the ring is suspended and we need to emit a
request to clear the idle ring.
Reported-by: Jinjin, Wang <jinjin.wang@intel.com>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=30380Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

* 'upstream-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jlbec/ocfs2:
  ocfs2_connection_find() returns pointer to bad structure
  ocfs2: char is not always signed
  Ocfs2: Stop tracking a negative dentry after dentry_iput().
  ocfs2: fix memory leak
  fs/ocfs2/dlm: Use GFP_ATOMIC under spin_lock

Commit 0ea12930 ("arm: return both physical and virtual addresses
from addruart") took out the test for MMU on/off but didn't switch the
ldr instructions to no longer be conditionals based on said test.

Fix that.
Signed-off-by: Olof Johansson <olof@lixom.net>
Acked-by: Colin Cross <ccross@android.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

The existing gpio-keys driver can be usable only for GPIO lines with
interrupt support. Several devices have buttons connected to a GPIO
line which is not capable to generate interrupts. This patch adds a
new input driver using the generic GPIO layer and the input-polldev
to support such buttons.

[Ben Gardiner <bengardiner@nanometrics.ca: fold code to use more
 of the original gpio_keys infrastructure; cleanups and other
 improvements.]
Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
Signed-off-by: Ben Gardiner <bengardiner@nanometrics.ca>
Tested-by: Ben Gardiner <bengardiner@nanometrics.ca>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

* 'pm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/suspend-2.6:
  PM / Hibernate: Fix memory corruption related to swap
  PM / Hibernate: Use async I/O when reading compressed hibernation image

There is a problem that swap pages allocated before the creation of
a hibernation image can be released and used for storing the contents
of different memory pages while the image is being saved.  Since the
kernel stored in the image doesn't know of that, it causes memory
corruption to occur after resume from hibernation, especially on
systems with relatively small RAM that need to swap often.

This issue can be addressed by keeping the GFP_IOFS bits clear
in gfp_allowed_mask during the entire hibernation, including the
saving of the image, until the system is finally turned off or
the hibernation is aborted.  Unfortunately, for this purpose
it's necessary to rework the way in which the hibernate and
suspend code manipulates gfp_allowed_mask.

This change is based on an earlier patch from Hugh Dickins.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Reported-by: Ondrej Zary <linux@rainbow-software.org>
Acked-by: Hugh Dickins <hughd@google.com>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: stable@kernel.org

* master.kernel.org:/home/rmk/linux-2.6-arm:
  ARM: 6524/1: GIC irq desciptor bug fix
  ARM: 6523/1: iop: ensure sched_clock() is notrace
  ARM: 6456/1: Fix for building DEBUG with sa11xx_base.c as a module.
  ARM: 6519/1: kuser: Fix incorrect cmpxchg syscall in kuser helpers
  ARM: 6505/1: kprobes: Don't HAVE_KPROBES when CONFIG_THUMB2_KERNEL is selected
  ARM: 6508/1: vexpress: Correct data alignment in headsmp.S for CONFIG_THUMB2_KERNEL
  ARM: 6507/1: RealView: Correct data alignment in headsmp.S for CONFIG_THUMB2_KERNEL
  ARM: 6504/1: Thumb-2: Fix long-distance conditional branches in head.S for Thumb-2.
  ARM: 6503/1: Thumb-2: Restore sensible zImage header layout for CONFIG_THUMB2_KERNEL
  ARM: 6502/1: Thumb-2: Fix CONFIG_THUMB2_KERNEL breakage in compressed/head.S
  ARM: 6501/1: Thumb-2: Correct data alignment for CONFIG_THUMB2_KERNEL in mm/proc-v7.S
  ARM: 6500/1: Thumb-2: Correct data alignment for CONFIG_THUMB2_KERNEL in kernel/head.S
  ARM: 6499/1: Thumb-2: Correct data alignment for CONFIG_THUMB2_KERNEL in bootp/init.S
  ARM: 6498/1: vfp: Correct data alignment for CONFIG_THUMB2_KERNEL
  ARM: 6497/1: kexec: Correct data alignment for CONFIG_THUMB2_KERNEL
  ARM: 6496/1: GIC: Do not try to register more then NR_IRQS interrupts
  ARM: cns3xxx: Fix build with CONFIG_PCI=y

This is a fix for reading LZO compressed image using async I/O.
Essentially, instead of having just one page into which we keep
reading blocks from swap, we allocate enough of them to cover the
largest compressed size and then let block I/O pick them all up. Once
we have them all (and here we wait), we decompress them, as usual.
Obviously, the very first block we still pick up synchronously,
because we need to know the size of the lot before we pick up the
rest.

Also fixed the copyright line, which I've forgotten before.
Signed-off-by: Bojan Smojver <bojan@rexursive.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>

While looking for the duplicates in /sys/class/wmi/, I couldn't find
them. The code that looks for duplicates uses strncmp in a binary GUID,
which may contain zero bytes. The right function is memcmp, which is
also used in another section of wmi code.

It was finding 49142400-C6A3-40FA-BADB-8A2652834100 as a duplicate of
39142400-C6A3-40FA-BADB-8A2652834100. Since the first byte is the fourth
printed, they were found as equal by strncmp.
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@holoscopio.com>
Signed-off-by: Matthew Garrett <mjg@redhat.com>
Cc: stable@kernel.org

When execvp fails to find the specified command on the path we won't get
SIGCHLD, so send a SIGUSR1 and exit right away.

Current situation would require a SIGINT performed by the user and would
produce meaningless summary.

Now:

[acme@emilia linux]$ ./foo
-bash: ./foo: No such file or directory
[acme@emilia linux]$ perf record ./foo
./foo: No such file or directory
[acme@emilia linux]$
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Tom Zanussi <tzanussi@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
LKML-Reference: <new-submission>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

gic_set_cpu will directly use irq_desc[]. If CONFIG_SPARSE_IRQ is
enabled, there is no irq_desc[]. So we need use irq_to_desc(irq) to
get the descriptor for irq.
Signed-off-by: Chao Xie <chao.xie@marvell.com>
Acked-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

* 'slab/urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg/slab-2.6:
  slub: Fix a crash during slabinfo -v

* 'rc-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild-2.6:
  initramfs: Really fix build break on symbol-prefixed archs
  [media] Fix Kconfig errors due to two visible menus
  i2c/algos: convert Kconfig to use the menu's `visible' keyword
  media/video: convert Kconfig to use the menu's `visible' keyword
  Revert "i2c: Fix Kconfig dependencies"
  kconfig: regen parser
  kconfig: add an option to determine a menu's visibility

* 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/kyle/parisc-2.6:
  parisc: Fix GSC PS/2 driver name for keyboard and mouse
  parisc: KittyHawk LCD fix
  parisc: convert the rest of the irq handlers to simple/percpu
  parisc: fix dino/gsc interrupts
  parisc: remove redundant initialization in sigsegv path of sys_rt_sigreturn