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: cpu_init(): fix memory leak when using CPU hotplug
  x86: pda_init(): fix memory leak when using CPU hotplug
  x86, xen: Use native_pte_flags instead of native_pte_val for .pte_flags
  x86: move mtrr cpu cap setting early in early_init_xxxx
  x86: delay early cpu initialization until cpuid is done
  x86: use X86_FEATURE_NOPL in alternatives
  x86: add NOPL as a synthetic CPU feature bit
  x86: boot: stub out unimplemented CPU feature words

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:
  clocksource, acpi_pm.c: check for monotonicity
  clocksource, acpi_pm.c: use proper read function also in errata mode
  ntp: fix calculation of the next jiffie to trigger RTC sync
  x86: HPET: read back compare register before reading counter
  x86: HPET fix moronic 32/64bit thinko
  clockevents: broadcast fixup possible waiters
  HPET: make minimum reprogramming delta useful
  clockevents: prevent endless loop lockup
  clockevents: prevent multiple init/shutdown
  clockevents: enforce reprogram in oneshot setup
  clockevents: prevent endless loop in periodic broadcast handler
  clockevents: prevent clockevent event_handler ending up handler_noop

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound-2.6:
  Fix CONFIG_AC97_BUS dependency

* 'upstream' of git://ftp.linux-mips.org/pub/scm/upstream-linus:
  [MIPS] Probe initrd header only if explicitly specified
  [MIPS] TX39xx: Add missing local_flush_icache_range initialization
  [MIPS] TXx9: Fix txx9_pcode initialization
  [MIPS] Fix WARNING: at kernel/smp.c:290
  [MIPS] Fix data bus error recovery

Exception stacks are allocated each time a CPU is set online.
But the allocated space is never freed. Thus with one CPU hotplug
offline/online cycle there is a memory leak of 24K (6 pages) for
a CPU.

Fix is to allocate exception stacks only once -- when the CPU is
set online for the first time.
Signed-off-by: NAndreas Herrmann <andreas.herrmann3@amd.com>
Cc: akpm@linux-foundation.org
Signed-off-by: NIngo Molnar <mingo@elte.hu>

pda->irqstackptr is allocated whenever a CPU is set online.
But it is never freed. This results in a memory leak of 16K
for each CPU offline/online cycle.

Fix is to allocate pda->irqstackptr only once.
Signed-off-by: NAndreas Herrmann <andreas.herrmann3@amd.com>
Cc: akpm@linux-foundation.org
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Using native_pte_val triggers the BUG_ON() in the paravirt_ops
version of pte_flags().
Signed-off-by: NEduardo Habkost <ehabkost@redhat.com>
Acked-by: NJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Krzysztof Helt found MTRR is not detected on k6-2

root cause:
	we moved mtrr_bp_init() early for mtrr trimming,
and in early_detect we only read the CPU capability from cpuid,
so some cpu doesn't have that bit in cpuid.

So we need to add early_init_xxxx to preset those bit before mtrr_bp_init
for those earlier cpus.

this patch is for v2.6.27
Reported-by: NKrzysztof Helt <krzysztof.h1@wp.pl>
Signed-off-by: NYinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Move early cpu initialization after cpu early get cap so the
early cpu initialization can fix up cpu caps.
Signed-off-by: NKrzysztof Helt <krzysztof.h1@wp.pl>
Signed-off-by: NYinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

The current check for monotonicity is way too weak: Andreas Mohr reports (
http://lkml.org/lkml/2008/8/10/77 ) that on one of his test systems the
current check only triggers in 50% of all cases, leading to catastrophic
timer behaviour.  To fix this issue, expand the check for monotonicity by
doing ten consecutive tests instead of one.
Signed-off-by: NDominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

On all hardware (some Intel ICH4, PIIX4 and PIIX4E chipsets) affected by a
hardware errata there's about a 4.2% chance that initialization of the
ACPI PMTMR fails.  On those chipsets, we need to read out the timer value
at least three times to get a correct result, for every once in a while
(i.e.  within a 3 ns window every 69.8 ns) the read returns a bogus
result.  During normal operation we work around this issue, but during
initialization reading a bogus value may lead to -EINVAL even though the
hardware is usable.

Thanks to Andreas Mohr for spotting this issue.
Signed-off-by: NDominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

We have a bug in the calculation of the next jiffie to trigger the RTC
synchronisation.  The aim here is to run sync_cmos_clock() as close as
possible to the middle of a second.  Which means we want this function to
be called less than or equal to half a jiffie away from when now.tv_nsec
equals 5e8 (500000000).

If this is not the case for a given call to the function, for this purpose
instead of updating the RTC we calculate the offset in nanoseconds to the
next point in time where now.tv_nsec will be equal 5e8.  The calculated
offset is then converted to jiffies as these are the unit used by the
timer.

Hovewer timespec_to_jiffies() used here uses a ceil()-type rounding mode,
where the resulting value is rounded up.  As a result the range of
now.tv_nsec when the timer will trigger is from 5e8 to 5e8 + TICK_NSEC
rather than the desired 5e8 - TICK_NSEC / 2 to 5e8 + TICK_NSEC / 2.

As a result if for example sync_cmos_clock() happens to be called at the
time when now.tv_nsec is between 5e8 + TICK_NSEC / 2 and 5e8 to 5e8 +
TICK_NSEC, it will simply be rescheduled HZ jiffies later, falling in the
same range of now.tv_nsec again.  Similarly for cases offsetted by an
integer multiple of TICK_NSEC.

This change addresses the problem by subtracting TICK_NSEC / 2 from the
nanosecond offset to the next point in time where now.tv_nsec will be
equal 5e8, effectively shifting the following rounding in
timespec_to_jiffies() so that it produces a rounded-to-nearest result.
Signed-off-by: NMaciej W. Rozycki <macro@linux-mips.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

CONFIG_AC97_BUS is used from both sound and ucb1400 drivers.
The recent change in Kconfig introduced the exclusive dependency on
CONFIG_SOUND, and disabled the ucb1400 build without sound.
This patch makes CONFIG_AC97_BUS independent.
Signed-off-by: NTakashi Iwai <tiwai@suse.de>
Tested-by: NRandy Dunlap <randy.dunlap@oracle.com>

After fixing the u32 thinko I sill had occasional hickups on ATI chipsets
with small deltas. There seems to be a delay between writing the compare
register and the transffer to the internal register which triggers the
interrupt. Reading back the value makes sure, that it hit the internal
match register befor we compare against the counter value.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

We use the HPET only in 32bit mode because:
1) some HPETs are 32bit only
2) on i386 there is no way to read/write the HPET atomic 64bit wide

The HPET code unification done by the "moron of the year" did
not take into account that unsigned long is different on 32 and
64 bit.

This thinko results in a possible endless loop in the clockevents
code, when the return comparison fails due to the 64bit/332bit
unawareness. 

unsigned long cnt = (u32) hpet_read() + delta can wrap over 32bit.
but the final compare will fail and return -ETIME causing endless
loops.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

Until the C1E patches arrived there where no users of periodic broadcast
before switching to oneshot mode. Now we need to trigger a possible
waiter for a periodic broadcast when switching to oneshot mode.
Otherwise we can starve them for ever.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

Use X86_FEATURE_NOPL to determine if it is safe to use P6 NOPs in
alternatives.  Also, replace table and loop with simple if statement.
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>

The long noops ("NOPL") are supposed to be detected by family >= 6.
Unfortunately, several non-Intel x86 implementations, both hardware
and software, don't obey this dictum.  Instead, probe for NOPL
directly by executing a NOPL instruction and see if we get #UD.
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>

The CPU feature detection code in the boot code is somewhat minimal,
and doesn't include all possible CPUID words.  In particular, it
doesn't contain the code for CPU feature words 2 (Transmeta),
3 (Linux-specific), 5 (VIA), or 7 (scattered).  Zero them out, so we
can still set those bits as known at compile time; in particular, this
allows creating a Linux-specific NOPL flag and have it required (and
therefore resolvable at compile time) in 64-bit mode.
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>

mmc_block_open() increments md->usage although it returns with -EROFS when
default mounting a MMC/SD card with write protect switch on.  This
reference counting bug prevents /dev/mmcblkX from being released on card
removal, and situation worsen with reinsertion until the minor number
range runs out.

Reported-by: <sasin@solomon-systech.com>
Acked-by: NPierre Ossman <drzeus-list@drzeus.cx>
Cc: <stable@kernel.org>		[2.6.25.x, 2.6.26.x]
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Fix some pasto's in comments in the new linux/tracehook.h and
asm-generic/syscall.h files.
Reported-by: NWenji Huang <wenji.huang@oracle.com>
Signed-off-by: NRoland McGrath <roland@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

If framebuffer registration failed in platform driver ->probe() callback,
dev_get_drvdata() points to freed memory region, but ->remove() function
try to use it and the following oops occurs:

Unable to handle kernel NULL pointer dereference at virtual address 00000228
pgd = c3a20000
[00000228] *pgd=23a2b031, *pte=00000000, *ppte=00000000
Internal error: Oops: 17 [#1]
Modules linked in: atmel_lcdfb(-) cfbcopyarea cfbimgblt cfbfillrect [last unloaded: atmel_lcdfb]
CPU: 0    Not tainted  (2.6.27-rc2 #116)
PC is at atmel_lcdfb_remove+0x14/0xf8 [atmel_lcdfb]
LR is at platform_drv_remove+0x20/0x24
pc : [<bf006bc4>]    lr : [<c0157d28>]    psr: a0000013
sp : c3a45e84  ip : c3a45ea0  fp : c3a45e9c
r10: 00000002  r9 : c3a44000  r8 : c0026c04
r7 : 00000880  r6 : c02bb228  r5 : 00000000  r4 : c02bb230
r3 : bf007e3c  r2 : c02bb230  r1 : 00000004  r0 : c02bb228
Flags: NzCv  IRQs on  FIQs on  Mode SVC_32  ISA ARM  Segment user
Control: 0005317f  Table: 23a20000  DAC: 00000015
Process rmmod (pid: 6799, stack limit = 0xc3a44260)
Stack: (0xc3a45e84 to 0xc3a46000)
5e80:          c02bb230 bf007e3c bf007e3c c3a45eac c3a45ea0 c0157d28 bf006bc0
5ea0: c3a45ec4 c3a45eb0 c0156d20 c0157d18 c02bb230 c02bb2d8 c3a45ee0 c3a45ec8
5ec0: c0156da8 c0156cb8 bf007e3c bf007ee0 c02c8e14 c3a45efc c3a45ee4 c0156018
5ee0: c0156d50 bf007e3c bf007ee0 00000000 c3a45f18 c3a45f00 c0157220 c0155f9c
5f00: 00000000 bf007ee0 bf008000 c3a45f28 c3a45f1c c0157e34 c01571ec c3a45f38
5f20: c3a45f2c bf006ba8 c0157e30 c3a45fa4 c3a45f3c c005772c bf006ba4 656d7461
5f40: 636c5f6c 00626664 c004c988 c3a45f80 c3a45f5c 00000000 c3a45fb0 00000000
5f60: ffffffff becaccd8 00000880 00000000 000a5e80 00000001 bf007ee0 00000880
5f80: c3a45f84 00000000 becaccd4 00000002 000003df 00000081 00000000 c3a45fa8
5fa0: c0026a60 c0057584 00000002 000003df 00900081 000a5e80 00000880 00000000
5fc0: becaccd4 00000002 000003df 00000000 000a5e80 00000001 00000002 0000005f
5fe0: 4004f5ec becacbe8 0001a158 4004f5fc 20000010 00900081 f9ffbadf 7bbfb2bb
Backtrace:
[<bf006bb0>] (atmel_lcdfb_remove+0x0/0xf8 [atmel_lcdfb]) from [<c0157d28>] (platform_drv_remove+0x20/0x24)
 r6:bf007e3c r5:bf007e3c r4:c02bb230
[<c0157d08>] (platform_drv_remove+0x0/0x24) from [<c0156d20>] (__device_release_driver+0x78/0x98)
[<c0156ca8>] (__device_release_driver+0x0/0x98) from [<c0156da8>] (driver_detach+0x68/0x90)
 r5:c02bb2d8 r4:c02bb230
[<c0156d40>] (driver_detach+0x0/0x90) from [<c0156018>] (bus_remove_driver+0x8c/0xb4)
 r6:c02c8e14 r5:bf007ee0 r4:bf007e3c
[<c0155f8c>] (bus_remove_driver+0x0/0xb4) from [<c0157220>] (driver_unregister+0x44/0x48)
 r6:00000000 r5:bf007ee0 r4:bf007e3c
[<c01571dc>] (driver_unregister+0x0/0x48) from [<c0157e34>] (platform_driver_unregister+0x14/0x18)
 r6:bf008000 r5:bf007ee0 r4:00000000
[<c0157e20>] (platform_driver_unregister+0x0/0x18) from [<bf006ba8>] (atmel_lcdfb_exit+0x14/0x1c [atmel_lcdfb])
[<bf006b94>] (atmel_lcdfb_exit+0x0/0x1c [atmel_lcdfb]) from [<c005772c>] (sys_delete_module+0x1b8/0x22c)
[<c0057574>] (sys_delete_module+0x0/0x22c) from [<c0026a60>] (ret_fast_syscall+0x0/0x2c)
 r7:00000081 r6:000003df r5:00000002 r4:becaccd4
Code: e92dd870 e24cb004 e59050c4 e1a06000 (e5954228)
---[ end trace 85476b184d9e68d8 ]---

This patch fixes the oops.
Signed-off-by: NStanislaw Gruszka <stf_xl@wp.pl>
Acked-by: NNicolas Ferre <nicolas.ferre@atmel.com>
Acked-by: NKrzysztof Helt <krzysztof.h1@wp.pl>
Cc: Haavard Skinnemoen <hskinnemoen@atmel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Fix regression tracked as http://bugzilla.kernel.org/show_bug.cgi?id=11361
and caused by commit f735a2a1 ("[netdrvr]
forcedeth: setup wake-on-lan before shutting down") that makes network
adapters integrated into the NVidia MCP55 chipsets fail to work in kexeced
kernels.  The problem appears to be that if the adapter is put into D3_hot
during ->shutdown(), it cannot be brought back into D0 after kexec (ref.
http://marc.info/?l=linux-kernel&m=121900062814967&w=4).  Therefore, only
put forcedeth into D3 during ->shutdown() if the system is to be powered
off.
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>
Tested-by: NYinghai Lu <yhlu.kernel@gmail.com>
Cc: Ayaz Abdulla <aabdulla@nvidia.com>
Acked-by: NJeff Garzik <jeff@garzik.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

I found we can no longer set limit to 0 with 2.6.27-rcX:
 # mount -t cgroup -omemory xxx /mnt
 # mkdir /mnt/0
 # echo 0 > /mnt/0/memory.limit_in_bytes
 bash: echo: write error: Device or resource busy

It turned out 'limit' can't be set to 'usage', which is wrong IMO.
Signed-off-by: NLi Zefan <lizf@cn.fujitsu.com>
Acked-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: NBalbir Singh <balbir@linux.vnet.ibm.com>
Acked-by: NPavel Emelyanov <xemul@openvz.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

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

* 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  sched: fix process time monotonicity
  sched_clock: fix NOHZ interaction

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: add io delay quirk for Presario F700

* 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/djbw/async_tx:
  async_tx: fix the bug in async_tx_run_dependencies

* git://git.infradead.org/~dwmw2/dwmw2-2.6.27:
  Revert "[ARM] use the new byteorder headers"
  Fix conditional export of kvh.h and a.out.h to userspace.
  [MTD] [NAND] tmio_nand: fix base address programming

* 'sh/for-2.6.27' of git://git.kernel.org/pub/scm/linux/kernel/git/lethal/sh-2.6:
  i2c: fix i2c-sh_mobile timing issues
  sh64: resume_kernel fix for kernel oops built with CONFIG_BKL_PREEMPT=y.
  sh: resume_kernel fix for kernel oops built with CONFIG_BKL_PREEMPT=y.
  sh: fix semtimedop syscall
  sh: update AP325RXA defconfig
  sh: update Migo-R defconfig
  sh: fix platform_resource_setup_memory() section mismatch
  sh: fix kexec entry point for crash kernels
  sh: crash kernel resource fix
  sh: fix ptrace_64.c:user_disable_single_step()
  sh64: re-add the __strnlen_user() prototype

* 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/v4l-dvb: (98 commits)
  V4L/DVB (8881): gspca: After 'while (retry--) {...}', retry will be -1 but not 0.
  V4L/DVB (8880): PATCH: Fix parents on some webcam drivers
  V4L/DVB (8877): b2c2 and bt8xx: udelay to mdelay
  V4L/DVB (8876): budget: udelay changed to mdelay
  V4L/DVB (8874): gspca: Adjust hstart for sn9c103/ov7630 and update usb-id's.
  V4L/DVB (8873): gspca: Bad image offset with rev012a of spca561 and adjust exposure.
  V4L/DVB (8872): gspca: Bad image format and offset with rev072a of spca561.
  V4L/DVB (8870): gspca: Fix dark room problem with sonixb.
  V4L/DVB (8869): gspca: Move the Sonix webcams with TAS5110C1B from sn9c102 to gspca.
  V4L/DVB (8868): gspca: Support for vga modes with sif sensors in sonixb.
  V4L/DVB (8844): dabusb_fpga_download(): fix a memory leak
  V4L/DVB (8843): tda10048_firmware_upload(): fix a memory leak
  V4L/DVB (8842): vivi_release(): fix use-after-free
  V4L/DVB (8840): dib0700: add basic support for Hauppauge Nova-TD-500 (84xxx)
  V4L/DVB (8839): dib0700: add comment to identify 35th USB id pair
  V4L/DVB (8837): dvb: fix I2C adapters name size
  V4L/DVB (8835): gspca: Same pixfmt as the sn9c102 driver and raw Bayer added in sonixb.
  V4L/DVB (8834): gspca: Have a bigger buffer for sn9c10x compressed images.
  V4L/DVB (8833): gspca: Cleanup the sonixb code.
  V4L/DVB (8832): gspca: Bad pixelformat of vc0321 webcams.
  ...

* 'core/debugobjects' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  debugobjects: fix lockdep warning

* 'release-2.6.27' of git://git.kernel.org/pub/scm/linux/kernel/git/ak/linux-acpi-2.6:
  acer-wmi: remove debugfs entries upon unloading
  ACPI: Avoid bogus timeout about SMbus check
  fujitsu-laptop: fix regression for P8010 in 2.6.27-rc
  ACPI: Make Len Brown the ACPI maintainer again
  ACPI: thinkpad-acpi: wan radio control is not experimental
  PNPACPI: ignore the producer/consumer bit for extended IRQ descriptors
  acpi: add checking for NULL early param
  ACPI: Fix typo in "Disable MWAIT via DMI on broken Compal board"
  ACPI: Fix now signed module parameter.
  ACPI: Change package length error to warning
  ACPI: Fix now signed module parameter.

Currently init_initrd() probes initrd header at the last page of kernel
image, but it is valid only if addinitrd was used.  If addinitrd was not
used, the area contains garbage so probing there might misdetect initrd
header (magic number is not strictly robust).

This patch introduces CONFIG_PROBE_INITRD_HEADER to explicitly enable this
probing.
Signed-off-by: NAtsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Commmit 59e39ecd933ba49eb6efe84cbfa5597a6c9ef18a ("Fix WARNING: at
kernel/smp.c:290") introduced local_flush_icache_range but lacks
initialization for some TX39 case.
Signed-off-by: NAtsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

The txx9_pcode variable was introduced in commit
fe1c2bc64f65003b39f331a8e4b0d15b235a4afd ("TXx9: Add 64-bit support")
but was not initialized properly.
Signed-off-by: NAtsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

trap_init issues flush_icache_range(), which uses ipi functions to
get icache flushing done on all cpus. But this is done before interrupts
are enabled and caused WARN_ON messages. This changeset introduces
a new local_flush_icache_range() and uses it before interrupts (and
additional CPUs) are enabled to avoid this problem.
Signed-off-by: NThomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

With -ffunction-section the entries in __dbe_table aren't no longer
sorted, so the lookup of exception addresses in do_be() failed for
some addresses. To avoid this we now sort __dbe_table.
Signed-off-by: NThomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

This reverts commit 087d833e, which was
reported to break wireless at least in some combinations with 32bit user
space and a 64bit kernel.  Alex Williamnson bisected it to this commit.
Reported-and-bisected-by: NAlex Williamson <alex.williamson@hp.com>
Acked-by: NJohn W. Linville <linville@tuxdriver.com>
Cc: David Miller <davem@davemloft.net>
Cc: Jouni Malinen <jouni.malinen@atheros.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Spencer reported a problem where utime and stime were going negative despite
the fixes in commit b27f03d4. The suspected
reason for the problem is that signal_struct maintains it's own utime and
stime (of exited tasks), these are not updated using the new task_utime()
routine, hence sig->utime can go backwards and cause the same problem
to occur (sig->utime, adds tsk->utime and not task_utime()). This patch
fixes the problem

TODO: using max(task->prev_utime, derived utime) works for now, but a more
generic solution is to implement cputime_max() and use the cputime_gt()
function for comparison.

Reported-by: spencer@bluehost.com
Signed-off-by: NBalbir Singh <balbir@linux.vnet.ibm.com>
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

If HLT stops the TSC, we'll fail to account idle time, thereby inflating the
actual process times. Fix this by re-calibrating the clock against GTOD when
leaving nohz mode.
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Tested-by: NAvi Kivity <avi@qumranet.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>