Some trace shows lots of bdi_dirty=0 lines where it's actually some
small value if w/o the accounting errors in the per-cpu bdi stats.

In this case the max pause time should really be set to the smallest
(non-zero) value to avoid IO queue underrun and improve throughput.
Signed-off-by: NWu Fengguang <fengguang.wu@intel.com>

On a system with 1 local mount and 1 NFS mount, if the NFS server
becomes not responding when dd to the NFS mount, the NFS dirty pages may
exceed the global dirty limit and _every_ task involving writing will be
blocked. The whole system appears unresponsive.

The workaround is to permit through the bdi's that only has a small
number of dirty pages. The number chosen (bdi_stat_error pages) is not
enough to enable the local disk to run in optimal throughput, however is
enough to make the system responsive on a broken NFS mount. The user can
then kill the dirtiers on the NFS mount and increase the global dirty
limit to bring up the local disk's throughput.

It risks allowing dirty pages to grow much larger than the global dirty
limit when there are 1000+ mounts, however that's very unlikely to happen,
especially in low memory profiles.
Signed-off-by: NWu Fengguang <fengguang.wu@intel.com>

We do "floating proportions" to let active devices to grow its target
share of dirty pages and stalled/inactive devices to decrease its target
share over time.

It works well except in the case of "an inactive disk suddenly goes
busy", where the initial target share may be too small. To mitigate
this, bdi_position_ratio() has the below line to raise a small
bdi_thresh when it's safe to do so, so that the disk be feed with enough
dirty pages for efficient IO and in turn fast rampup of bdi_thresh:

        bdi_thresh = max(bdi_thresh, (limit - dirty) / 8);

balance_dirty_pages() normally does negative feedback control which
adjusts ratelimit to balance the bdi dirty pages around the target.
In some extreme cases when that is not enough, it will have to block
the tasks completely until the bdi dirty pages drop below bdi_thresh.
Acked-by: NJan Kara <jack@suse.cz>
Acked-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: NWu Fengguang <fengguang.wu@intel.com>

Currently write(2) to a file is not interruptible by any signal.
Sometimes this is desirable, e.g. when you want to quickly kill a
process hogging your disk. Also, with commit 499d05ec ("mm: Make
task in balance_dirty_pages() killable"), it's necessary to abort the
current write accordingly to avoid it quickly dirtying lots more pages
at unthrottled rate.

This patch makes write interruptible by SIGKILL. We do not allow write
to be interruptible by any other signal because that has larger
potential of screwing some badly written applications.
Reported-by: NKazuya Mio <k-mio@sx.jp.nec.com>
Tested-by: NKazuya Mio <k-mio@sx.jp.nec.com>
Acked-by: NMatthew Wilcox <matthew.r.wilcox@intel.com>
Signed-off-by: NJan Kara <jack@suse.cz>
Signed-off-by: NWu Fengguang <fengguang.wu@intel.com>

Document the @reason parameter to make "make htmldocs" happy.
Acked-by: NRandy Dunlap <rdunlap@xenotime.net>
Signed-off-by: NMarcos Paulo de Souza <marcos.mage@gmail.com>
Signed-off-by: NWu Fengguang <fengguang.wu@intel.com>

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux:
  efivars: add missing parameter to efi_pstore_read()

In the case where CONFIG_PSTORE=n, the function efi_pstore_read() doesn't
have the correct list of parameters. This patch provides a definition
of efi_pstore_read() with 'char **buf' added to fix this warning:
"drivers/firmware/efivars.c:609: warning: initialization from".

problem introduced in commit f6f82851Signed-off-by: NChristoph Fritz <chf.fritz@googlemail.com>
Signed-off-by: NTony Luck <tony.luck@intel.com>

* 'for-3.2-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
  cgroup_freezer: fix freezing groups with stopped tasks

* 'for-3.2-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu:
  percpu: explain why per_cpu_ptr_to_phys() is more complicated than necessary
  percpu: fix chunk range calculation
  percpu: rename pcpu_mem_alloc to pcpu_mem_zalloc

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux:
  pstore: pass allocated memory region back to caller

* 'drm-fixes' of git://people.freedesktop.org/~airlied/linux:
  drm/exynos: fixed wrong err ptr usage and destroy call in exeception
  drm/exynos: Add disable of manager
  drm/exynos: include linux/module.h
  drm/exynos: fix vblank bug.
  drm/exynos: changed buffer structure.
  drm/exynos: removed unnecessary variable.
  drm/exynos: use gem create function generically
  drm/exynos: checked for null pointer
  drm/exynos: added crtc dpms for disable crtc
  drm/exynos: removed meaningless parameter from fbdev update
  drm/exynos: restored kernel_fb_list when reiniting fb_helper
  drm/exynos: changed exynos_drm_display to exynos_drm_display_ops
  drm/exynos: added manager object to connector
  drm/exynos: fixed converting between display mode and timing
  drm/exynos: fixed connector flag with hpd and interlace scan for hdmi
  drm/exynos: added kms poll for handling hpd event

* 'bugfixes' of git://git.linux-nfs.org/projects/trondmy/linux-nfs:
  SUNRPC: Ensure we return EAGAIN in xs_nospace if congestion is cleared

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound: (28 commits)
  ALSA: hda - Fix jack-detection control of VT1708
  ALSA: hda - cut and paste typo in cs420x_models[]
  ALSA: hda/realtek - Minor cleanup
  ALSA: hda/realtek - Fix missing inits of item indices for auto-mic
  ALSA: hda - Fix invalid pin and GPIO for Apple laptops with CS codecs
  ALSA: hda - Check subdevice mask in snd_hda_check_board_codec_sid_config()
  ALSA: hda - fail ELD reading early
  ALSA: lx6464es - fix device communication via command bus
  ALSA: lx6464es - command buffer API cleanup
  ALSA: hda - repoll ELD content for multiple times
  ALSA: hdspm - Fix PCI ID for PCIe RME MADI cards
  ASoC: Ensure WM8731 register cache is synced when resuming from disabled
  ALSA: cs5535 - Fix an endianness conversion
  ASoC: cs4271: Fix wrong mask parameter in some snd_soc_update_bits calls
  ASoC: wm_hubs: fix DB_RANGE size
  ASoC: wm9090: fix DB_RANGE size
  ASoC: wm8993: fix DB_RANGE size
  ASoC: wm8962: fix DB_RANGE size
  ASoC: sgtl5000: fix DB_RANGE size
  ASoC: rt5631: fix DB_RANGE size
  ...

* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  hrtimer: Fix extra wakeups from __remove_hrtimer()
  timekeeping: add arch_offset hook to ktime_get functions
  clocksource: Avoid selecting mult values that might overflow when adjusted
  time: Improve documentation of timekeeeping_adjust()

* 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  genirq: Don't allow per cpu interrupts to be suspended

Commit fa27271b("genirq: Fixup poll handling") introduced a
regression that broke irqfixup/irqpoll for some hardware configurations.

Amidst reorganizing 'try_one_irq', that patch removed a test that
checked for 'action->handler' returning IRQ_HANDLED, before acting on
the interrupt.  Restoring this test back returns the functionality lost
since 2.6.39.  In the current set of tests, after 'action' is set, it
must precede '!action->next' to take effect.

With this and my previous patch to irq/spurious.c, c75d720f, all
IRQ regressions that I have encountered are fixed.
Signed-off-by: NEdward Donovan <edward.donovan@numble.net>
Reported-and-tested-by: NRogério Brito <rbrito@ime.usp.br>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@kernel.org (2.6.39+)
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

* 'exynos-drm' of git://git.infradead.org/users/kmpark/linux-samsung:
  drm/exynos: fixed wrong err ptr usage and destroy call in exeception
  drm/exynos: Add disable of manager
  drm/exynos: include linux/module.h
  drm/exynos: fix vblank bug.
  drm/exynos: changed buffer structure.
  drm/exynos: removed unnecessary variable.
  drm/exynos: use gem create function generically
  drm/exynos: checked for null pointer
  drm/exynos: added crtc dpms for disable crtc
  drm/exynos: removed meaningless parameter from fbdev update
  drm/exynos: restored kernel_fb_list when reiniting fb_helper
  drm/exynos: changed exynos_drm_display to exynos_drm_display_ops
  drm/exynos: added manager object to connector
  drm/exynos: fixed converting between display mode and timing
  drm/exynos: fixed connector flag with hpd and interlace scan for hdmi
  drm/exynos: added kms poll for handling hpd event

* 'fbdev-for-linus' of git://github.com/schandinat/linux-2.6:
  viafb: correct sync polarity for OLPC DCON
  video:da8xx-fb: Disable and reset sequence on version2 of LCDC
  OMAPDSS: DISPC: skip scaling calculations when not scaling
  OMAPFB: fix compilation warnings due to missing include
  OMAPDSS: HDMI: fix returned HDMI pixel clock

Revert a hunk in drivers/net/wireless/ath/ath9k/hw.c introduced by
commit 2577c6e8 ("ath9k_hw: Add support for AR946/8x chipsets") that
caused a nasty regression to appear on my Acer Ferrari One (the box
locks up entirely at random times after the wireless has been started
without any way to get debug information out of it).
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>
Acked-by: NFelix Fietkau <nbd@openwrt.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

VT1708 has no support for unsolicited events per jack-plug, the driver
implements the workq for polling the jack-detection.  The mixer element
"Jack Detect" was supposed to control this behavior on/off, but this
doesn't work properly as is now.  The workq is always started and the
HP automute is always enabled.

This patch fixes the jack-detect control behavior by triggering / stopping
the work appropriately at the state change.  Also the work checks the
internal state to continue scheduling or not.

Cc: <stable@kernel.org> [v3.1]
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

The CS420X_IMAC27 was copied from the line before but CS420X_APPLE
was clearly intented.
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

Fix build failure in staging iio driver:

.../drivers/staging/iio/industrialio-core.c: In function 'iio_event_getfd':
.../drivers/staging/iio/industrialio-core.c:262:32: error:
			'ev_int' undeclared (first use in this function)

Also convert the rest of the function to use the new variable.
Signed-off-by: NAndy Whitcroft <apw@canonical.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

* 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc:
  powerpc/44x: Add mtd ndfc to the ppx44x defconfig
  powerpc: Fix compiliation with hugetlbfs enabled
  arch/powerpc/sysdev/ehv_pic.c: add missing kfree
  powerpc/fsl-lbc: Fix for fsl_upm
  drivers/edac/mpc85xx_edac.c: fix memory controller compatible for edac
  powerpc/qe: Fixup QE_General4 errata
  powerpc/85xx: Fix compile error on p3060_qds.c
  powerpc/p3060qds: Fix select of 'MPC8xxx_GPIO'
  powerpc/p1023: set IRQ[4:6,11] to active-high level sensitive for PCIe

* git://github.com/herbertx/crypto:
  crypto: mv_cesa - fix hashing of chunks > 1920 bytes

* 'gpio-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-stericsson:
  gpio: pca953x: Staticise pca953x_get_altdata()

Signed-off-by: NTony Breeds <tony@bakeyournoodle.com>
Acked-by: NJosh Boyer <jwboyer@gmail.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

arch/powerpc/mm/hugetlbpage.c: In function 'reserve_hugetlb_gpages':
arch/powerpc/mm/hugetlbpage.c:312:2: error: implicit declaration of function 'parse_args'
Signed-off-by: NKumar Gala <galak@kernel.crashing.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

2d3cbf8b (cgroup_freezer: update_freezer_state() does incorrect state
transitions) removed is_task_frozen_enough and replaced it with a simple
frozen call. This, however, breaks freezing for a group with stopped tasks
because those cannot be frozen and so the group remains in CGROUP_FREEZING
state (update_if_frozen doesn't count stopped tasks) and never reaches
CGROUP_FROZEN.

Let's add is_task_frozen_enough back and use it at the original locations
(update_if_frozen and try_to_freeze_cgroup). Semantically we consider
stopped tasks as frozen enough so we should consider both cases when
testing frozen tasks.

Testcase:
mkdir /dev/freezer
mount -t cgroup -o freezer none /dev/freezer
mkdir /dev/freezer/foo
sleep 1h &
pid=$!
kill -STOP $pid
echo $pid > /dev/freezer/foo/tasks
echo FROZEN > /dev/freezer/foo/freezer.state
while true
do
	cat /dev/freezer/foo/freezer.state
	[ "`cat /dev/freezer/foo/freezer.state`" = "FROZEN" ] && break
	sleep 1
done
echo OK
Signed-off-by: NMichal Hocko <mhocko@suse.cz>
Acked-by: NLi Zefan <lizf@cn.fujitsu.com>
Cc: Tomasz Buchert <tomasz.buchert@inria.fr>
Cc: Paul Menage <paul@paulmenage.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: stable@kernel.org
Signed-off-by: NTejun Heo <htejun@gmail.com>

At this point, ehv_pic has been allocated but not stored anywhere, so it
should be freed before leaving the function.

A simplified version of the semantic match that finds this problem is as
follows: (http://coccinelle.lip6.fr/)

// <smpl>
@exists@
local idexpression x;
statement S,S1;
expression E;
identifier fl;
expression *ptr != NULL;
@@

x = \(kmalloc\|kzalloc\|kcalloc\)(...);
...
if (x == NULL) S
<... when != x
     when != if (...) { <+...kfree(x)...+> }
     when any
     when != true x == NULL
x->fl
...>
(
if (x == NULL) S1
|
if (...) { ... when != x
               when forall
(
 return \(0\|<+...x...+>\|ptr\);
|
* return ...;
)
}
)
// </smpl>
Signed-off-by: NJulia Lawall <julia@diku.dk>
Acked-by: NTimur Tabi <timur@freescale.com>
Signed-off-by: NKumar Gala <galak@kernel.crashing.org>

If Freescale LBC driver fails to initialise itself from device tree, then
internal structure is freed only but not NULL-fied.  As result functions
fsl_lbc_find() after checking the structure is not NULL are trying to
access device registers.
Signed-off-by: NAlexandre Rusev <arusev@dev.rtsoft.ru>
Signed-off-by: NKumar Gala <galak@kernel.crashing.org>

compatible in dts has been changed, so the driver needs to be updated
accordingly.
Signed-off-by: NShaohui Xie <Shaohui.Xie@freescale.com>
Cc: Grant Likely <grant.likely@secretlab.ca>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NKumar Gala <galak@kernel.crashing.org>

QE_General4 should only round up the divisor iff divisor is > 3.
Rounding up lower divisors makes the error too big, causing USB
on MPC832x to fail.
Signed-off-by: NJoakim Tjernlund <Joakim.Tjernlund@transmode.se>
Acked-by: NTimur Tabi <timur@freescale.com>
Signed-off-by: NKumar Gala <galak@kernel.crashing.org>

arch/powerpc/platforms/85xx/p3060_qds.c: In function '__machine_initcall_p3060_qds_declare_of_platform_devices':
arch/powerpc/platforms/85xx/p3060_qds.c:73:1: error: implicit declaration of function 'declare_of_platform_devices'

declare_of_platform_devices should have been corenet_ds_publish_devices.
Signed-off-by: NKumar Gala <galak@kernel.crashing.org>

The driver for the Freescale P3060 QDS got added by commit 96cc017c
("[...] Add support for P3060QDS board"). Its Kconfig entry selects
MPC8xxx_GPIO. But at the time that driver got added MPC8xxx_GPIO was
already renamed to GPIO_MPC8XXX, by commit c68308dd ("gpio: move
mpc8xxx/512x gpio driver to drivers/gpio").

So make this driver select GPIO_MPC8XXX.
Signed-off-by: NPaul Bolle <pebolle@tiscali.nl>
Acked-by: NWolfram Sang <w.sang@pengutronix.de>
Signed-off-by: NKumar Gala <galak@kernel.crashing.org>

P1023 external IRQ[4:6, 11] are not pin out, but the interrupts are
utilized by the PCIe controllers.  As they are not exposed as pins we
need to set them as active-high (internal to the SoC these interrupts
are pulled down).

IRQs[0:3,7:10] are pulled up on the board so we have them set as
active-low.
Signed-off-by: NRoy Zang <tie-fei.zang@freescale.com>
Signed-off-by: NKumar Gala <galak@kernel.crashing.org>

* git://github.com/rustyrussell/linux:
  virtio-pci: make reset operation safer
  virtio-mmio: Correct the name of the guest features selector
  virtio: add HAS_IOMEM dependency to MMIO platform bus driver

virtio pci device reset actually just does an I/O
write, which in PCI is really posted, that is it
can complete on CPU before the device has received it.

Further, interrupts might have been pending on
another CPU, so device callback might get invoked after reset.

This conflicts with how drivers use reset, which is typically:
	reset
	unregister
a callback running after reset completed can race with
unregister, potentially leading to use after free bugs.

Fix by flushing out the write, and flushing pending interrupts.

This assumes that device is never reset from
its vq/config callbacks, or in parallel with being
added/removed, document this assumption.
Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

Guest features selector spelling mistake.

Cc: Pawel Moll <pawel.moll@arm.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: virtualization@lists.linux-foundation.org
Signed-off-by: NSasha Levin <levinsasha928@gmail.com>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>