the slack estimator used unsigned math; however for very short delay it's
possible that by the time you calculate the timeout, it's already passed and
you get a negative time/slack... in an unsigned variable... which then gets
turned into a 100 msec delay rather than zero.

This patch fixes this by using a signed typee in the right places.
Signed-off-by: NArjan van de Ven <arjan@linux.intel.com>

to help debugging and visibility of timer ranges, show them
in the existing timer list in /proc/timer_list
Signed-off-by: NArjan van de Ven <arjan@linux.intel.com>

(based on  lkml review)
* use rt_task()
* task_nice() has a sign
Signed-off-by: NArjan van de Ven <arjan@linux.intel.com>

this patch adds a _range version of hrtimer_start() so that range timers
can be created; the hrtimer_start() function is just a wrapper around this.

In addition, hrtimer_start_expires() will now preserve existing ranges.
Signed-off-by: NArjan van de Ven <arjan@linux.intel.com>

More randconfig testing
Signed-off-by: NArjan van de Ven <arjan@linux.intel.com>

in some randconfig configurations, hrtimers are used even though
the hrtimer config if off; and it broke the build due to some of
the new functions being on the wrong side of the ifdef.

This patch moves the functions to the other side of the ifdef, fixing
the build bug.
Signed-off-by: NArjan van de Ven <arjan@linux.intel.com>

This patch makes the select() and poll() hrtimers use the new range
feature and settings from the task struct.

In addition, this includes the estimate_accuracy() function that Linus
posted to lkml, but changed entirely based on other peoples lkml feedback.
Signed-off-by: NArjan van de Ven <arjan@linux.intel.com>

We want to be able to control the default "rounding" that is used by
select() and poll() and friends. This is a per process property
(so that we can have a "nice" like program to start certain programs with
a looser or stricter rounding) that can be set/get via a prctl().

For this purpose, a field called "timer_slack_ns" is added to the task
struct. In addition, a field called "default_timer_slack"ns" is added
so that tasks easily can temporarily to a more/less accurate slack and then
back to the default.

The default value of the slack is set to 50 usec; this is significantly less
than 2.6.27's average select() and poll() timing error but still allows
the kernel to group timers somewhat to preserve power behavior. Applications
and admins can override this via the prctl()
Signed-off-by: NArjan van de Ven <arjan@linux.intel.com>

this patch turns hrtimers into range timers; they have 2 expire points
1) the soft expire point
2) the hard expire point

the kernel will do it's regular best effort attempt to get the timer run
at the hard expire point. However, if some other time fires after the soft
expire point, the kernel now has the freedom to fire this timer at this point,
and thus grouping the events and preventing a power-expensive wakeup in the
future.
Signed-off-by: NArjan van de Ven <arjan@linux.intel.com>

To catch code that still touches the "expires" memory directly, rename it
to have the compiler complain rather than get nasty, hard to explain,
runtime behavior
Signed-off-by: NArjan van de Ven <arjan@linux.intel.com>

In order to be able to do range hrtimers we need to use accessor functions
to the "expire" member of the hrtimer struct.
This patch converts sound/ to these accessors.
Signed-off-by: NArjan van de Ven <arjan@linux.intel.com>

In order to be able to do range hrtimers we need to use accessor functions
to the "expire" member of the hrtimer struct.
This patch converts s390 to these accessors.
Signed-off-by: NArjan van de Ven <arjan@linux.intel.com>

In order to be able to do range hrtimers we need to use accessor functions
to the "expire" member of the hrtimer struct.
This patch converts KVM-ia64 to these accessors.
Signed-off-by: NArjan van de Ven <arjan@linux.intel.com>

In order to be able to do range hrtimers we need to use accessor functions
to the "expire" member of the hrtimer struct.
This patch converts powerpc/oprofile to these accessors.
Signed-off-by: NArjan van de Ven <arjan@linux.intel.com>

In order to be able to do range hrtimers we need to use accessor functions
to the "expire" member of the hrtimer struct.
This patch converts kernel/* to these accessors.
Signed-off-by: NArjan van de Ven <arjan@linux.intel.com>

In order to be able to do range hrtimers we need to use accessor functions
to the "expire" member of the hrtimer struct.
This patch converts sched_cbq to these accessors.
Signed-off-by: NArjan van de Ven <arjan@linux.intel.com>

In order to be able to do range hrtimers we need to use accessor functions
to the "expire" member of the hrtimer struct.
This patch converts timerfd to these accessors.
Signed-off-by: NArjan van de Ven <arjan@linux.intel.com>

In order to be able to do range hrtimers we need to use accessor functions
to the "expire" member of the hrtimer struct.
This patch converts KVM to these accessors.
Signed-off-by: NArjan van de Ven <arjan@linux.intel.com>

In order to be able to turn hrtimers into range based, we need to provide
accessor functions for getting to the "expires" ktime_t member of the
struct hrtimer.

This patch adds a set of accessors for this purpose:
* hrtimer_set_expires
* hrtimer_set_expires_tv64
* hrtimer_add_expires
* hrtimer_add_expires_ns
* hrtimer_get_expires
* hrtimer_get_expires_tv64
* hrtimer_get_expires_ns
* hrtimer_expires_remaining
* hrtimer_start_expires

No users of these new accessors are added yet; these follow in later patches.
Hopefully this patch can even go into 2.6.27-rc so that the conversions will
not have a bottleneck in -next
Signed-off-by: NArjan van de Ven <arjan@linux.intel.com>

With lots of help, input and cleanups from Thomas Gleixner

This patch switches select() and poll() over to hrtimers.

The core of the patch is replacing the "s64 timeout" with a
"struct timespec end_time" in all the plumbing.

But most of the diffstat comes from using the just introduced helpers:
	poll_select_set_timeout
	poll_select_copy_remaining
	timespec_add_safe
which make manipulating the timespec easier and less error-prone.
Signed-off-by: NArjan van de Ven <arjan@linux.intel.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

with hrtimer poll/select, the signal restart data no longer is a single
long representing a jiffies count, but it becomes a second/nanosecond pair
that also needs to encode if there was a timeout at all or not.

This patch adds a struct to the restart_block union for this purpose
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NArjan van de Ven <arjan@linux.intel.com>

This patch adds 2 helpers that will be used for the hrtimer based select/poll:

poll_select_set_timeout() is a helper that takes a timeout (as a second, nanosecond
pair) and turns that into a "struct timespec" that represents the absolute end time.
This is a common operation in the many select() and poll() variants and needs various,
common, sanity checks.

poll_select_copy_remaining() is a helper that takes care of copying the remaining
time to userspace, as select(), pselect() and ppoll() do. This function comes in
both a natural and a compat implementation (due to datastructure differences).
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NArjan van de Ven <arjan@linux.intel.com>

For the select() rework, it's important to be able to add timespec
structures in an overflow-safe manner.

This patch adds a timespec_add_safe() function for this which is similar in
operation to ktime_add_safe(), but works on a struct timespec.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NArjan van de Ven <arjan@linux.intel.com>

This patch adds a schedule_hrtimeout() function, to be used by select() and
poll() in a later patch. This function works similar to schedule_timeout()
in most ways, but takes a timespec rather than jiffies.

With a lot of contributions/fixes from Thomas
Signed-off-by: NArjan van de Ven <arjan@linux.intel.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

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.

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>