* 'pm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/suspend-2.6:
  PM: Reintroduce dropped call to check_wakeup_irqs

* git://git.kernel.org/pub/scm/linux/kernel/git/sfrench/cifs-2.6:
  cifs: drop spinlock before calling cifs_put_tlink
  cifs: fix expand_dfs_referral
  cifs: move bdi_setup_and_register outside of CONFIG_CIFS_DFS_UPCALL
  cifs: factor smb_vol allocation out of cifs_setup_volume_info
  cifs: have cifs_cleanup_volume_info not take a double pointer
  cifs: fix build_unc_path_to_root to account for a prefixpath
  cifs: remove bogus call to cifs_cleanup_volume_info

* 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/davej/cpufreq:
  [CPUFREQ] fix cpumask memory leak in acpi-cpufreq on cpu hotplug.

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:
  hp-wmi: fix use after free
  dell-laptop - using buffer without mutex_lock
  Revert: "dell-laptop: Toggle the unsupported hardware killswitch"
  platform-drivers-x86: set backlight type to BACKLIGHT_PLATFORM
  thinkpad-acpi: handle HKEY 0x4010, 0x4011 events
  drivers/platform/x86: Fix memory leak
  thinkpad-acpi: handle some new HKEY 0x60xx events
  acer-wmi: fix bitwise bug when set device state
  acer-wmi: Only update rfkill status for associated hotkey events

* 'movieboard' of git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394/linux1394-2.6:
  firewire: ohci: do not bind to Pinnacle cards, avert panic

Signed-off-by: Joe Perches <joe@perches.com>
Acked-by: Pavel Roskin <proski@gnu.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Since we removed sti()/cli() and related, how about removing it from
Documentation/spinlocks.txt?
Signed-off-by: Muthukumar R <muthur@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

...as that function can sleep.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>

[  191.310008] WARNING: kmemcheck: Caught 32-bit read from freed memory (f0d25f14)
[  191.310011] c056d2f088000000105fd2f00000000050415353040000000000000000000000
[  191.310020]  i i i i f f f f f f f f f f f f f f f f f f f f f f f f f f f f
[  191.310027]                                          ^
[  191.310029]
[  191.310032] Pid: 737, comm: modprobe Not tainted 3.0.0-rc5+ #268 Hewlett-Packard HP Compaq 6005 Pro SFF PC/3047h
[  191.310036] EIP: 0060:[<f80b3104>] EFLAGS: 00010286 CPU: 0
[  191.310039] EIP is at hp_wmi_perform_query+0x104/0x150 [hp_wmi]
[  191.310041] EAX: f0d25601 EBX: f0d25f00 ECX: 000121cf EDX: 000121ce
[  191.310043] ESI: f0d25f10 EDI: f0f97ea8 EBP: f0f97ec4 ESP: c173f34c
[  191.310045]  DS: 007b ES: 007b FS: 00d8 GS: 0033 SS: 0068
[  191.310046] CR0: 8005003b CR2: f540c000 CR3: 30f30000 CR4: 000006d0
[  191.310048] DR0: 00000000 DR1: 00000000 DR2: 00000000 DR3: 00000000
[  191.310050] DR6: ffff4ff0 DR7: 00000400
[  191.310051]  [<f80b317b>] hp_wmi_dock_state+0x2b/0x40 [hp_wmi]
[  191.310054]  [<f80b6093>] hp_wmi_init+0x93/0x1a8 [hp_wmi]
[  191.310057]  [<c10011f0>] do_one_initcall+0x30/0x170
[  191.310061]  [<c107ab9f>] sys_init_module+0xef/0x1a60
[  191.310064]  [<c149f998>] sysenter_do_call+0x12/0x28
[  191.310067]  [<ffffffff>] 0xffffffff
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Matthew Garrett <mjg@redhat.com>

Using buffer->output[1] without mutex_lock()
Signed-off-by: Jose Alonso <joalonsof@gmail.com>
Signed-off-by: Matthew Garrett <mjg@redhat.com>

This reverts commit a3d77411,

as it causes a mess in the wireless rfkill status on some models.
It is probably a bad idea to toggle the rfkill for all dell models
without the respect to the claim that it is hardware-controlled.

Cc: stable@kernel.org
Signed-off-by: Keng-Yu Lin <kengyu@canonical.com>
Signed-off-by: Matthew Garrett <mjg@redhat.com>

Patch 2e711c04
(PM: Remove sysdev suspend, resume and shutdown operations)
deleted sysdev_suspend(), which was being relied on to call
check_wakeup_irqs() in suspend.  If check_wakeup_irqs() is not
called, wake interrupts that are pending when suspend is
entered may be lost.  It also breaks IRQCHIP_MASK_ON_SUSPEND,
which is handled in check_wakeup_irqs().

This patch adds a call to check_wakeup_irqs() in syscore_suspend(),
similar to what was deleted in sysdev_suspend().
Signed-off-by: Colin Cross <ccross@android.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>

I came across a memory leak during a cyclic cpu-online-offline test.
Signed-off-by: Yu Luming <luming.yu@intel.com>
Cc: Len Brown <lenb@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Dave Jones <davej@redhat.com>

* 'hwmon-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/staging:
  hwmon: (pmbus) Improve auto-detection of temperature status register
  hwmon: (lm95241) Fix negative temperature results
  hwmon: (lm95241) Fix chip detection code

It is possible that a PMBus device supports the READ_TEMPERATURE2 and/or
READ_TEMPERATURE3 registers but does not support READ_TEMPERATURE1.
Improve temperature status register detection to address this condition.
Reported-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Guenter Roeck <guenter.roeck@ericsson.com>
Acked-by: Jean Delvare <khali@linux-fr.org>
Cc: stable@kernel.org # 2.6.39+

Negative temperatures were returned in degrees C instead of milli-Degrees C.
Also, negative temperatures were reported for remote temperature sensors even
if the chip was configured for positive-only results.

Fix by detecting temperature modes, and by treating negative temperatures
similar to positive temperatures, with appropriate sign extension.
Signed-off-by: Guenter Roeck <guenter.roeck@ericsson.com>
Acked-by: Jean Delvare <khali@linux-fr.org>
Cc: stable@kernel.org # 2.6.30+

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound-2.6:
  ALSA: hda - Fix a copmile warning
  ASoC: ak4642: fixup snd_soc_update_bits mask for PW_MGMT2
  ALSA: hda - Change all ADCs for dual-adc switching mode for Realtek
  ASoC: Manage WM8731 ACTIVE bit as a supply widget
  ASoC: Don't set invalid name string to snd_card->driver field
  ASoC: Ensure we delay long enough for WM8994 FLL to lock when starting
  ASoC: Tegra: I2S: Ensure clock is enabled when writing regs
  ASoC: Fix Blackfin I2S _pointer() implementation return in bounds values
  ASoC: tlv320aic3x: Do soft reset to codec when going to bias off state
  ASoC: tlv320aic3x: Don't sync first two registers from register cache
  audio: tlv320aic26: fix PLL register configuration

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci-2.6:
  PCI: conditional resource-reallocation through kernel parameter pci=realloc

* 'fixes' of master.kernel.org:/home/rmk/linux-2.6-arm:
  ARM: 6994/1: smp_twd: Fix typo in 'twd_timer_rate' printing
  ARM: 6987/1: l2x0: fix disabling function to avoid deadlock
  ARM: 6966/1: ep93xx: fix inverted RTS/DTR signals on uart1
  ARM: 6980/1: mmci: use StartBitErr to detect bad connections
  ARM: 6979/1: mach-vt8500: add forgotten irq_data conversion
  ARM: move memory layout sanity checking before meminfo initialization
  ARM: 6990/1: MAINTAINERS: add entry for ARM PMU profiling and debugging
  ARM: 6989/1: perf: do not start the PMU when no events are present
  ARM: dmabounce: fix map_single() error return value

* 'drm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/airlied/drm-2.6:
  drm/radeon/kms: clean up multiple crtc handling for evergreen+ (v2)

When firewire-ohci is bound to a Pinnacle MovieBoard, eventually a
"Register access failure" is logged and an interrupt storm or a kernel
panic happens.  https://bugzilla.kernel.org/show_bug.cgi?id=36622

Until this is sorted out (if that is going to succeed at all), let's
just prevent firewire-ohci from touching these devices.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Cc: <stable@kernel.org>

Regression introduced in commit 724d9f1c.

Prior to that, expand_dfs_referral would regenerate the mount data string
and then call cifs_parse_mount_options to re-parse it (klunky, but it
worked). The above commit moved cifs_parse_mount_options out of cifs_mount,
so the re-parsing of the new mount options no longer occurred. Fix it by
making expand_dfs_referral re-parse the mount options.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>

This needs to be done regardless of whether that KConfig option is set
or not.
Reported-by: Sven-Haegar Koch <haegar@sdinet.de>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>

It's harmless but annyoing.
  sound/pci/hda/patch_realtek.c: In function ‘alc_cap_getput_caller’:
  sound/pci/hda/patch_realtek.c:2722:9: warning: ‘err’ may be used uninitialized in this function
Signed-off-by: Takashi Iwai <tiwai@suse.de>

Merge branch 'for-3.0' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound-2.6 into fix/asoc

Merge branch 's5p-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/kgene/linux-samsung

* 's5p-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/kgene/linux-samsung:
  ARM: S3C2440: fix section mismatch on mini2440
  ARM: S3C24XX: drop return codes in void function of dma.c
  ARM: S3C24XX: don't use uninitialized variable in dma.c
  ARM: EXYNOS4: Set appropriate I2C device variant
  ARM: S5PC100: Fix for compilation error
  spi/s3c64xx: Bug fix for SPI with different FIFO level
  ARM: SAMSUNG: Add tx_st_done variable
  ARM: EXYNOS4: Address a section mismatch w/ suspend issue.
  ARM: S5P: Fix bug on init of PWMTimers for HRTimer
  ARM: SAMSUNG: header file revised to prevent declaring duplicated
  ARM: EXYNOS4: fix improper gpio configuration
  ARM: EXYNOS4: Fix card detection for sdhci 0 and 2

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/lrg/voltage-2.6:
  regulator: max8997: Fix setting inappropriate value for ramp_delay variable
  regulator: db8500-prcmu: small fixes
  regulator: max8997: remove dependency on platform_data pointer
  regulator: MAX8997: Fix for divide by zero error
  regulator: max8952 - fix wrong gpio valid check

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable:
  btrfs: fix oops when doing space balance
  Btrfs: don't panic if we get an error while balancing V2
  btrfs: add missing options displayed in mount output

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

This driver handles the variants pca9530-pca9533, so it chose the name
"pca953x".  However, there is a gpio driver which decided on the same
name.  As a result, those two can't be loaded at the same time.  Add a
subsystem prefix to make the driver name unique.  Device matching will not
suffer, because both are I2C drivers which match using a
i2c_device_id-table which is not altered.
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
Acked-by: Jean Delvare <khali@linux-fr.org>
Cc: Richard Purdie <richard.purdie@linuxfoundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

remap_pfn_range() means map physical address pfn<<PAGE_SHIFT to user addr.

For nommu arch it's implemented by vma->vm_start = pfn << PAGE_SHIFT which
is wrong acroding the original meaning of this function.  And some driver
developer using remap_pfn_range() with correct parameter will get
unexpected result because vm_start is changed.  It should be implementd
like addr = pfn << PAGE_SHIFT but which is meanless on nommu arch, this
patch just make it simply return.

Parameter name and setting of vma->vm_flags also be fixed.
Signed-off-by: Bob Liu <lliubbo@gmail.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: David Howells <dhowells@redhat.com>
Acked-by: Greg Ungerer <gerg@uclinux.org>
Cc: Mike Frysinger <vapier@gentoo.org>
Cc: Bob Liu <lliubbo@gmail.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

This fixes a regression in 3.0 reported by Paul Parsons regarding the
removal of the msleep(1) in the ds1wm_reset() function:

: The linux-3.0-rc4 DS1WM 1-wire driver is logging "bus error, retrying"
: error messages on an HP iPAQ hx4700 PDA (XScale-PXA270):
:
: <snip>
: Driver for 1-wire Dallas network protocol.
: DS1WM w1 busmaster driver - (c) 2004 Szabolcs Gyurko
: 1-Wire driver for the DS2760 battery monitor  chip  - (c) 2004-2005, Szabolcs Gyurko
: ds1wm ds1wm: pass: 1 bus error, retrying
: ds1wm ds1wm: pass: 2 bus error, retrying
: ds1wm ds1wm: pass: 3 bus error, retrying
: ds1wm ds1wm: pass: 4 bus error, retrying
: ds1wm ds1wm: pass: 5 bus error, retrying
: ...
:
: The visible result is that the battery charging LED is erratic; sometimes
: it works, mostly it doesn't.
:
: The linux-2.6.39 DS1WM 1-wire driver worked OK.  I haven't tried 3.0-rc1,
: 3.0-rc2, or 3.0-rc3.

This sleep should not be required on normal circuitry provided the
pull-ups on the bus are correctly adapted to the slaves.  Unfortunately,
this is not always the case.  The sleep is restored but as a parameter to
the probe function in the pdata.

[akpm@linux-foundation.org: coding-style fixes]
Reported-by: Paul Parsons <lost.distance@yahoo.com>
Tested-by: Paul Parsons <lost.distance@yahoo.com>
Signed-off-by: Jean-François Dagenais <dagenaisj@sonatest.com>
Cc: Evgeniy Polyakov <johnpol@2ka.mipt.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

commit 889976db ("memcg: reclaim memory from nodes in round-robin
order") adds an numa node round-robin for memcg.  But the information is
updated once per 10sec.

This patch changes the update trigger from jiffies to memcg's event count.
 After this patch, numa scan information will be updated when we see 1024
events of pagein/pageout under a memcg.

[akpm@linux-foundation.org: attempt to repair code layout]
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Ying Han <yinghan@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Now, in mem_cgroup_hierarchical_reclaim(), mem_cgroup_local_usage() is
used for checking whether the memcg contains reclaimable pages or not.  If
no pages in it, the routine skips it.

But, mem_cgroup_local_usage() contains Unevictable pages and cannot handle
"noswap" condition correctly.  This doesn't work on a swapless system.

This patch adds test_mem_cgroup_reclaimable() and replaces
mem_cgroup_local_usage().  test_mem_cgroup_reclaimable() see LRU counter
and returns correct answer to the caller.  And this new function has
"noswap" argument and can see only FILE LRU if necessary.

[akpm@linux-foundation.org: coding-style fixes]
[akpm@linux-foundation.org: fix kerneldoc layout]
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Ying Han <yinghan@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

__tlb_remove_page() switches to a new batch page, but still checks space
in the old batch.  This check always fails, and causes a forced tlb flush.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

During allocator-intensive workloads, kswapd will be woken frequently
causing free memory to oscillate between the high and min watermark.  This
is expected behaviour.  Unfortunately, if the highest zone is small, a
problem occurs.

When balance_pgdat() returns, it may be at a lower classzone_idx than it
started because the highest zone was unreclaimable.  Before checking if it
should go to sleep though, it checks pgdat->classzone_idx which when there
is no other activity will be MAX_NR_ZONES-1.  It interprets this as it has
been woken up while reclaiming, skips scheduling and reclaims again.  As
there is no useful reclaim work to do, it enters into a loop of shrinking
slab consuming loads of CPU until the highest zone becomes reclaimable for
a long period of time.

There are two problems here.  1) If the returned classzone or order is
lower, it'll continue reclaiming without scheduling.  2) if the highest
zone was marked unreclaimable but balance_pgdat() returns immediately at
DEF_PRIORITY, the new lower classzone is not communicated back to kswapd()
for sleeping.

This patch does two things that are related.  If the end_zone is
unreclaimable, this information is communicated back.  Second, if the
classzone or order was reduced due to failing to reclaim, new information
is not read from pgdat and instead an attempt is made to go to sleep.  Due
to this, it is also necessary that pgdat->classzone_idx be initialised
each time to pgdat->nr_zones - 1 to avoid re-reads being interpreted as
wakeups.
Signed-off-by: Mel Gorman <mgorman@suse.de>
Reported-by: Pádraig Brady <P@draigBrady.com>
Tested-by: Pádraig Brady <P@draigBrady.com>
Tested-by: Andrew Lutomirski <luto@mit.edu>
Acked-by: Rik van Riel <riel@redhat.com>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

When deciding if kswapd is sleeping prematurely, the classzone is taken
into account but this is different to what balance_pgdat() and the
allocator are doing.  Specifically, the DMA zone will be checked based on
the classzone used when waking kswapd which could be for a GFP_KERNEL or
GFP_HIGHMEM request.  The lowmem reserve limit kicks in, the watermark is
not met and kswapd thinks it's sleeping prematurely keeping kswapd awake in
error.
Signed-off-by: Mel Gorman <mgorman@suse.de>
Reported-by: Pádraig Brady <P@draigBrady.com>
Tested-by: Pádraig Brady <P@draigBrady.com>
Tested-by: Andrew Lutomirski <luto@mit.edu>
Acked-by: Rik van Riel <riel@redhat.com>
Reviewed-by: Minchan Kim <minchan.kim@gmail.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

During allocator-intensive workloads, kswapd will be woken frequently
causing free memory to oscillate between the high and min watermark.  This
is expected behaviour.

When kswapd applies pressure to zones during node balancing, it checks if
the zone is above a high+balance_gap threshold.  If it is, it does not
apply pressure but it unconditionally shrinks slab on a global basis which
is excessive.  In the event kswapd is being kept awake due to a high small
unreclaimable zone, it skips zone shrinking but still calls shrink_slab().

Once pressure has been applied, the check for zone being unreclaimable is
being made before the check is made if all_unreclaimable should be set.
This miss of unreclaimable can cause has_under_min_watermark_zone to be
set due to an unreclaimable zone preventing kswapd backing off on
congestion_wait().
Signed-off-by: Mel Gorman <mgorman@suse.de>
Reported-by: Pádraig Brady <P@draigBrady.com>
Tested-by: Pádraig Brady <P@draigBrady.com>
Tested-by: Andrew Lutomirski <luto@mit.edu>
Acked-by: Rik van Riel <riel@redhat.com>
Reviewed-by: Minchan Kim <minchan.kim@gmail.com>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

During allocator-intensive workloads, kswapd will be woken frequently
causing free memory to oscillate between the high and min watermark.  This
is expected behaviour.  Unfortunately, if the highest zone is small, a
problem occurs.

This seems to happen most with recent sandybridge laptops but it's
probably a co-incidence as some of these laptops just happen to have a
small Normal zone.  The reproduction case is almost always during copying
large files that kswapd pegs at 100% CPU until the file is deleted or
cache is dropped.

The problem is mostly down to sleeping_prematurely() keeping kswapd awake
when the highest zone is small and unreclaimable and compounded by the
fact we shrink slabs even when not shrinking zones causing a lot of time
to be spent in shrinkers and a lot of memory to be reclaimed.

Patch 1 corrects sleeping_prematurely to check the zones matching
	the classzone_idx instead of all zones.

Patch 2 avoids shrinking slab when we are not shrinking a zone.

Patch 3 notes that sleeping_prematurely is checking lower zones against
	a high classzone which is not what allocators or balance_pgdat()
	is doing leading to an artifical belief that kswapd should be
	still awake.

Patch 4 notes that when balance_pgdat() gives up on a high zone that the
	decision is not communicated to sleeping_prematurely()

This problem affects 2.6.38.8 for certain and is expected to affect 2.6.39
and 3.0-rc4 as well.  If accepted, they need to go to -stable to be picked
up by distros and this series is against 3.0-rc4.  I've cc'd people that
reported similar problems recently to see if they still suffer from the
problem and if this fixes it.

This patch: correct the check for kswapd sleeping in sleeping_prematurely()

During allocator-intensive workloads, kswapd will be woken frequently
causing free memory to oscillate between the high and min watermark.  This
is expected behaviour.

A problem occurs if the highest zone is small.  balance_pgdat() only
considers unreclaimable zones when priority is DEF_PRIORITY but
sleeping_prematurely considers all zones.  It's possible for this sequence
to occur

  1. kswapd wakes up and enters balance_pgdat()
  2. At DEF_PRIORITY, marks highest zone unreclaimable
  3. At DEF_PRIORITY-1, ignores highest zone setting end_zone
  4. At DEF_PRIORITY-1, calls shrink_slab freeing memory from
        highest zone, clearing all_unreclaimable. Highest zone
        is still unbalanced
  5. kswapd returns and calls sleeping_prematurely
  6. sleeping_prematurely looks at *all* zones, not just the ones
     being considered by balance_pgdat. The highest small zone
     has all_unreclaimable cleared but the zone is not
     balanced. all_zones_ok is false so kswapd stays awake

This patch corrects the behaviour of sleeping_prematurely to check the
zones balance_pgdat() checked.
Signed-off-by: Mel Gorman <mgorman@suse.de>
Reported-by: Pádraig Brady <P@draigBrady.com>
Tested-by: Pádraig Brady <P@draigBrady.com>
Tested-by: Andrew Lutomirski <luto@mit.edu>
Acked-by: Rik van Riel <riel@redhat.com>
Reviewed-by: Minchan Kim <minchan.kim@gmail.com>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>