Now that range timers and deferred timers are common, I found a
problem with these using the "perf timechart" tool. Frans Pop also
reported high scheduler latencies via LatencyTop, when using
iwlagn.

It turns out that on x86, these two 'opportunistic' timers only get
checked when another "real" timer happens. These opportunistic
timers have the objective to save power by hitchhiking on other
wakeups, as to avoid CPU wakeups by themselves as much as possible.

The change in this patch runs this check not only at timer
interrupts, but at all (device) interrupts. The effect is that:

 1) the deferred timers/range timers get delayed less

 2) the range timers cause less wakeups by themselves because
    the percentage of hitchhiking on existing wakeup events goes up.

I've verified the working of the patch using "perf timechart", the
original exposed bug is gone with this patch. Frans also reported
success - the latencies are now down in the expected ~10 msec
range.
Signed-off-by: NArjan van de Ven <arjan@linux.intel.com>
Tested-by: NFrans Pop <elendil@planet.nl>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Mike Galbraith <efault@gmx.de>
LKML-Reference: <20091008064041.67219b13@infradead.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Commit f2e21c96 had unfortunate side
effects with cpufreq governors on some systems.

If the system did not switch into NOHZ mode ts->inidle is not set when
tick_nohz_stop_sched_tick() is called from the idle routine. Therefor
all subsequent calls from irq_exit() to tick_nohz_stop_sched_tick()
fail to call tick_nohz_start_idle(). This results in bogus idle
accounting information which is passed to cpufreq governors.

Set the inidle flag unconditionally of the NOHZ active state to keep
the idle time accounting correct in any case.

[ tglx: Added comment and tweaked the changelog ]
Reported-by: NSteven Noonan <steven@uplinklabs.net>
Signed-off-by: NEero Nurkkala <ext-eero.nurkkala@nokia.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Cc: Greg KH <greg@kroah.com>
Cc: Steven Noonan <steven@uplinklabs.net>
Cc: stable@kernel.org
LKML-Reference: <1254907901.30157.93.camel@eenurkka-desktop>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/ide-2.6:
  Revert "ide: try to use PIO Mode 0 during probe if possible"
  ide: use printk_once

* 'kvm-updates/2.6.32' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  KVM: add support for change_pte mmu notifiers
  KVM: MMU: add SPTE_HOST_WRITEABLE flag to the shadow ptes
  KVM: MMU: dont hold pagecount reference for mapped sptes pages
  KVM: Prevent overflow in KVM_GET_SUPPORTED_CPUID
  KVM: VMX: flush TLB with INVEPT on cpu migration
  KVM: fix LAPIC timer period overflow
  KVM: s390: fix memsize >= 4G
  KVM: SVM: Handle tsc in svm_get_msr/svm_set_msr correctly
  KVM: SVM: Fix tsc offset adjustment when running nested

* 'fixes-for-linus' of git://git.monstr.eu/linux-2.6-microblaze:
  microblaze: Clear sticky FSR register after saving it to func parametr
  microblaze: UMS is used only for MMU kernel

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc-2.6:
  sparc: using HZ needs an include of linux/param.h
  sparc32: convert to asm-generic/hardirq.h
  sparc64: Cache per-cpu %pcr register value in perf code.
  sparc64: Fix comment typo in perf_event.c
  sparc64: Minor coding style fixups in perf code.
  sparc64: Add a basic conflict engine in preparation for multi-counter support.
  sparc64: Increase vmalloc size to fix percpu regressions.
  sparc64: Add initial perf event conflict resolution and checks.
  sparc: Niagara1 perf event support.
  sparc: Add Niagara2 HW cache event support.
  sparc: Support all ultra3 and ultra4 derivatives.
  sparc: Support HW cache events.

In virtual environments (namely, Xen Dom0) virt <-> phys and
virt <-> isa-bus translations cannot be freely interchanged (and
even outside such environments it is not really correct to do so).
When looking at memory below 1M, the latter translations should
always be used.

iscsi_ibft_find.c part from: Martin Wilck <martin.wilck@ts.fujitsu.com>.
Signed-off-by: NJan Beulich <jbeulich@novell.com>
Signed-off-by: NPeter Jones <pjones@redhat.com>
Signed-off-by: NKonrad Rzeszutek Wilk <ketuzsezs@darnok.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

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

* 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  perf tools: Run generate-cmdlist.sh properly
  perf_event: Clean up perf_event_init_task()
  perf_event: Fix event group handling in __perf_event_sched_*()
  perf timechart: Add a power-only mode
  perf top: Add poll_idle to the skip list

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

* 'timers-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  hrtimer: Remove overly verbose "switch to high res mode" message

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

* 'tracing-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  kmemtrace: Fix up tracer registration
  tracing: Fix infinite recursion in ftrace_update_pid_func()

Merge branch 'x86-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: Don't leak 64-bit kernel register values to 32-bit processes
  x86, SLUB: Remove unused CONFIG FAST_CMPXCHG_LOCAL
  x86: earlyprintk: Fix regression to handle serial,ttySn as 1 arg
  x86: Don't generate cmpxchg8b_emu if CONFIG_X86_CMPXCHG64=y
  x86: Fix csum_ipv6_magic asm memory clobber
  x86: Optimize cmpxchg64() at build-time some more

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/gerg/m68knommu:
  m68knommu: fix rename of pt_regs offset defines breakage
  m68knommu: remove duplicated #include
  m68knommu: show KiB rather than pages in "Freeing initrd memory:" message

Previous patch d63678d607d0e37ec7abe5ceb545d7e8aab956a4 clear
it for noMMU kernel. This one do it for MMU.

Correct noMMU version
Signed-off-by: NMichal Simek <monstr@monstr.eu>

Signed-off-by: NMichal Simek <monstr@monstr.eu>

Signed-off-by: NStephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This reverts commit 60293364.

Based upon a report by David Fries, wherein his system hangs
on bootup with sis5513 controller, right after the CDROM
is registered by ide-cd.c and the TOC is first read.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

I'm skipping -rc2 because the -rc1 Makefile mistakenly said -rc2, so in
order to avoid confusion, I'm jumping from -rc1 to -rc3.  That way, when
'uname' (or an oops report) says 2.6.32-rc2, there's no confusion about
whether people perhaps meant -rc1 or -rc2.

Signed-off-by: NAlexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

* 'acpi-pad' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux-acpi-2.6:
  acpi_pad: build only on X86
  ACPI: create Processor Aggregator Device driver

Fixup trivial conflicts in MAINTAINERS file.

* 'sfi-release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux-sfi-2.6:
  SFI: remove __init from sfi_verify_table
  SFI: fix section mismatch warnings in sfi_core.c

* 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux-acpi-2.6:
  ACPI: EC: Don't parse DSDT for EC early init on Compal
  ACPI: EC: Rewrite DMI checks
  ACPI: dock: fix "sibiling" typo
  ACPI: kill overly verbose "throttling states" log messages
  ACPI: Fix bound checks for copy_from_user in the acpi /proc code
  ACPI: fix bus scanning memory leaks
  ACPI: EC: Restart command even if no interrupts from EC
  sony-laptop: Don't unregister the SPIC driver if it wasn't registered
  sony-laptop: remove _INI call at init time
  sony-laptop: SPIC unset IRQF_SHARED, set IRQF_DISABLED
  sony-laptop: remove device_ctrl and the SPIC mini drivers

* 'i2c-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jdelvare/staging:
  macintosh: Don't assume i2c device probing always succeeds
  i2c: Hide probe errors caused by ACPI resource conflicts
  i2c: Minor documentation update
  mfd: AB3100 drop unused module parameters
  Staging: IIO: tsl2561: Drop unused module parameters
  leds: leds-pca9532 - Drop unused module parameters
  ltc4215/ltc4245: Discard obsolete detect methods
  ds2482: Discard obsolete detect method
  max6875: Discard obsolete detect method
  i2c: Move misc devices documentation

If i2c device probing fails, then there is no driver to dereference
after calling i2c_new_device(). Stop assuming that probing will always
succeed, to avoid NULL pointer dereferences. We have an easier access
to the driver anyway.
Signed-off-by: NJean Delvare <khali@linux-fr.org>
Tested-by: NTim Shepard <shep@alum.mit.edu>
Cc: Colin Leroy <colin@colino.net>

When an ACPI resource conflict is detected, error messages are already
printed by ACPI. There's no point in causing the driver core to print
more error messages, so return one of the error codes for which no
message is printed.

This fixes bug #14293:
http://bugzilla.kernel.org/show_bug.cgi?id=14293Signed-off-by: NJean Delvare <khali@linux-fr.org>

The sysfs path to i2c adapters has changed recently, update the
documentation to reflect that change.
Signed-off-by: NJean Delvare <khali@linux-fr.org>

The I2C_CLIENT_INSMOD_1 macro is only useful for i2c drivers which
implement device detection. The ab3100 driver doesn't, so there is no
point in calling it.
Signed-off-by: NJean Delvare <khali@linux-fr.org>
Acked-by: NLinus Walleij <linus.walleij@stericsson.com>
Cc: Samuel Ortiz <sameo@linux.intel.com>

The I2C_CLIENT_INSMOD macro is only useful for i2c drivers which
implement device detection. The tsl2561 driver doesn't, so there
is no point in calling it.
Signed-off-by: NJean Delvare <khali@linux-fr.org>
Cc: Jonathan Cameron <jic23@cam.ac.uk>

The I2C_CLIENT_INSMOD_1 macro is only useful for i2c drivers which
implement device detection. The leds-pca9532 driver doesn't, so there
is no point in calling it.
Signed-off-by: NJean Delvare <khali@linux-fr.org>
Cc: Richard Purdie <rpurdie@rpsys.net>
Cc: Riku Voipio <riku.voipio@iki.fi>

There is no point in implementing a detect callback for the LTC4215
and LTC4245, as these devices can't be detected. It was there solely
to handle "force" module parameters to instantiate devices, but now
we have a better sysfs interface that can do the same.

So we can get rid of the ugly module parameters and the detect
callbacks. This shrinks the binary module sizes by 36% and 46%,
respectively.
Signed-off-by: NJean Delvare <khali@linux-fr.org>
Cc: Ira W. Snyder <iws@ovro.caltech.edu>

There is no point in implementing a detect callback for the DS2482, as
this device can't be detected. It was there solely to handle "force"
module parameters to instantiate devices, but now we have a better sysfs
interface that can do the same.

So we can get rid of the ugly module parameters and the detect callback.
This shrinks the binary module size by 21%.
Signed-off-by: NJean Delvare <khali@linux-fr.org>
Acked-by: NBen Gardner <gardner.ben@gmail.com>

There is no point in implementing a detect callback for the MAX6875, as
this device can't be detected. It was there solely to handle "force"
module parameters to instantiate devices, but now we have a better sysfs
interface that can do the same.

So we can get rid of the ugly module parameters and the detect callback.
This basically divides the binary module size by 2.
Signed-off-by: NJean Delvare <khali@linux-fr.org>
Acked-by: NWolfram Sang <w.sang@pengutronix.de>
Acked-by: NBen Gardner <gardner.ben@gmail.com>

Some times ago the eeprom and max6875 drivers moved to
drivers/misc/eeprom, but their documentation did not follow. It's
finally time to get rid of Documentation/i2c/chips.
Signed-off-by: NJean Delvare <khali@linux-fr.org>
Cc: Ben Gardner <gardner.ben@gmail.com>
Acked-by: NWolfram Sang <w.sang@pengutronix.de>

* 'for-linus' of git://git.kernel.dk/linux-2.6-block: (41 commits)
  Revert "Seperate read and write statistics of in_flight requests"
  cfq-iosched: don't delay async queue if it hasn't dispatched at all
  block: Topology ioctls
  cfq-iosched: use assigned slice sync value, not default
  cfq-iosched: rename 'desktop' sysfs entry to 'low_latency'
  cfq-iosched: implement slower async initiate and queue ramp up
  cfq-iosched: delay async IO dispatch, if sync IO was just done
  cfq-iosched: add a knob for desktop interactiveness
  Add a tracepoint for block request remapping
  block: allow large discard requests
  block: use normal I/O path for discard requests
  swapfile: avoid NULL pointer dereference in swapon when s_bdev is NULL
  fs/bio.c: move EXPORT* macros to line after function
  Add missing blk_trace_remove_sysfs to be in pair with blk_trace_init_sysfs
  cciss: fix build when !PROC_FS
  block: Do not clamp max_hw_sectors for stacking devices
  block: Set max_sectors correctly for stacking devices
  cciss: cciss_host_attr_groups should be const
  cciss: Dynamically allocate the drive_info_struct for each logical drive.
  cciss: Add usage_count attribute to each logical drive in /sys
  ...

This reverts commit a9327cac.

Corrado Zoccolo <czoccolo@gmail.com> reports:

"with 2.6.32-rc1 I started getting the following strange output from
"iostat -kx 2":
Linux 2.6.31bisect (et2) 	04/10/2009 	_i686_	(2 CPU)

avg-cpu:  %user   %nice %system %iowait  %steal   %idle
          10,70    0,00    3,16   15,75    0,00   70,38

Device:         rrqm/s   wrqm/s     r/s     w/s    rkB/s    wkB/s
avgrq-sz avgqu-sz   await  svctm  %util
sda              18,22     0,00    0,67    0,01    14,77     0,02
43,94     0,01   10,53 39043915,03 2629219,87
sdb              60,89     9,68   50,79    3,04  1724,43    50,52
65,95     0,70   13,06 488437,47 2629219,87

avg-cpu:  %user   %nice %system %iowait  %steal   %idle
           2,72    0,00    0,74    0,00    0,00   96,53

Device:         rrqm/s   wrqm/s     r/s     w/s    rkB/s    wkB/s
avgrq-sz avgqu-sz   await  svctm  %util
sda               0,00     0,00    0,00    0,00     0,00     0,00
0,00     0,00    0,00   0,00 100,00
sdb               0,00     0,00    0,00    0,00     0,00     0,00
0,00     0,00    0,00   0,00 100,00

avg-cpu:  %user   %nice %system %iowait  %steal   %idle
           6,68    0,00    0,99    0,00    0,00   92,33

Device:         rrqm/s   wrqm/s     r/s     w/s    rkB/s    wkB/s
avgrq-sz avgqu-sz   await  svctm  %util
sda               0,00     0,00    0,00    0,00     0,00     0,00
0,00     0,00    0,00   0,00 100,00
sdb               0,00     0,00    0,00    0,00     0,00     0,00
0,00     0,00    0,00   0,00 100,00

avg-cpu:  %user   %nice %system %iowait  %steal   %idle
           4,40    0,00    0,73    1,47    0,00   93,40

Device:         rrqm/s   wrqm/s     r/s     w/s    rkB/s    wkB/s
avgrq-sz avgqu-sz   await  svctm  %util
sda               0,00     0,00    0,00    0,00     0,00     0,00
0,00     0,00    0,00   0,00 100,00
sdb               0,00     4,00    0,00    3,00     0,00    28,00
18,67     0,06   19,50 333,33 100,00

Global values for service time and utilization are garbage. For
interval values, utilization is always 100%, and service time is
higher than normal.

I bisected it down to:
[a9327cac] Seperate read and write
statistics of in_flight requests
and verified that reverting just that commit indeed solves the issue
on 2.6.32-rc1."

So until this is debugged, revert the bad commit.
Signed-off-by: NJens Axboe <jens.axboe@oracle.com>

We cannot delay for the first dispatch of the async queue if it
hasn't dispatched at all, since that could present a local user
DoS attack vector using an app that just did slow timed sync reads
while filling memory.
Signed-off-by: NJens Axboe <jens.axboe@oracle.com>

this is needed for kvm if it want ksm to directly map pages into its
shadow page tables.

[marcelo: cast pfn assignment to u64]
Signed-off-by: NIzik Eidus <ieidus@redhat.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

this flag notify that the host physical page we are pointing to from
the spte is write protected, and therefore we cant change its access
to be write unless we run get_user_pages(write = 1).

(this is needed for change_pte support in kvm)
Signed-off-by: NIzik Eidus <ieidus@redhat.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

When using mmu notifiers, we are allowed to remove the page count
reference tooken by get_user_pages to a specific page that is mapped
inside the shadow page tables.

This is needed so we can balance the pagecount against mapcount
checking.

(Right now kvm increase the pagecount and does not increase the
mapcount when mapping page into shadow page table entry,
so when comparing pagecount against mapcount, you have no
reliable result.)
Signed-off-by: NIzik Eidus <ieidus@redhat.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

The number of entries is multiplied by the entry size, which can
overflow on 32-bit hosts.  Bound the entry count instead.
Reported-by: NDavid Wagner <daw@cs.berkeley.edu>
Cc: stable@kernel.org
Signed-off-by: NAvi Kivity <avi@redhat.com>

It is possible that stale EPTP-tagged mappings are used, if a
vcpu migrates to a different pcpu.

Set KVM_REQ_TLB_FLUSH in vmx_vcpu_load, when switching pcpus, which
will invalidate both VPID and EPT mappings on the next vm-entry.

Cc: stable@kernel.org
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>