This fixes a regression caused by 22c8ca78.

nobh_prepare_write() no longer marks the page uptodate, so
nobh_truncate_page() needs to do it.
Signed-off-by: NDave Kleikamp <shaggy@linux.vnet.ibm.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

I've only seen this on x86_64.

The vsyscall state only gets updated when a timer interrupts comes in.  So
if the time is set long before the next timer, there will be a period when
a gettimeofday() won't reflect the correct time.

I added an explicit update_vsyscall() during the settimeofday(), that way
the vsyscall state doesn't get stale.
Signed-off-by: NDaniel Walker <dwalker@mvista.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Acked-by: NIngo Molnar <mingo@elte.hu>
Acked-by: NJohn Stultz <johnstul@us.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Fix http://bugzilla.kernel.org/show_bug.cgi?id=8130Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Remove the no longer used custom_sched_clock.
Signed-off-by: NAdrian Bunk <bunk@stusta.de>
Acked-by: NZachary Amsden <zach@vmware.com>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The TIMER_SOFTIRQ runs the hrtimers during bootup until a usable
clocksource and clock event sources are registered.  The switch to high
resolution mode happens inside of the TIMER_SOFTIRQ, but runs the softirq
afterwards.  That way the tick emulation timer, which was set up in the
switch to highres might be executed in the softirq context, which is a BUG.
 The rbtree has not to be touched by the softirq after the highres switch.

This BUG was observed by Andres Salomon, who provided the information to
debug it.

Return early from the softirq, when the switch was sucessful.

[dilinger@debian.org: add debug warning]
[akpm@linux-foundation.org: make debug warning compile]
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Andres Salomon <dilinger@debian.org>
Acked-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NAndres Salomon <dilinger@debian.org>
Acked-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The description for the hrtimer_clock_base struct describes "hrtimer_base".
 That should be hrtimer_clock_base.
Signed-off-by: NAndres Salomon <dilinger@debian.org>
Acked-by: NThomas Gleixner <tglx@linutronix.de>
Acked-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The description for HRTIMER_CB_IRQSAFE_NO_SOFTIRQ is backwards; "NO
SOFTIRQ" sounds a whole lot like it means it must not be run in a softirq.
Signed-off-by: NAndres Salomon <dilinger@debian.org>
Acked-by: NThomas Gleixner <tglx@linutronix.de>
Acked-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Prior to commit 95492e46 ([PATCH] x86:
rewrite SMP TSC sync code), the headers in asm-i386 did not really require
anything in include/asm-x86_64.  This means that distributions such as
fedora did not include asm-x86_64 in kernel-devel headers for i386.  Ingo's
commit changed that, and broke things.  This is easy enough to hack around
in package builds by just including asm-x86_64 on i386, but that's kind of
annoying.  If anything, x86_64 should depend upon i386, not the other way
around.

This patch changes it so that asm-x86_64/tsc.h includes asm-i386/tsc.h,
rather than vice-versa.
Signed-off-by: NAndres Salomon <dilinger@debian.org>
Acked-by: NIngo Molnar <mingo@elte.hu>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The obsolete SA_xxx interrupt flags have been used despite the scheduled
removal.  Fixup the remaining users.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Acked-by: NIngo Molnar <mingo@elte.hu>
Cc: Zachary Amsden <zach@vmware.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Any attempt to open/use a bluetooth rfcomm device locks up
scheduling completely on my machine.

Interrupts (ping, alt-sysrq) seem to be alive, but nothing else.

This was working fine in 2.6.20, broken now in 2.6.21-rc2-git*

Reverting this change (below) fixes it:

| author    Marcel Holtmann <marcel@holtmann.org>
|      Sat, 17 Feb 2007 22:58:57 +0000 (23:58 +0100)
| committer    David S. Miller <davem@sunset.davemloft.net>
|      Mon, 26 Feb 2007 19:42:41 +0000 (11:42 -0800)
| commit    c1a33136
| tree    337a876f727061362b6a169f8759849c105b8f7a    tree | snapshot
| parent    f5ffd462    commit | diff
| | [Bluetooth] Make use of device_move() for RFCOMM TTY devices
| | In the case of bound RFCOMM TTY devices the parent is not available
| before its usage. So when opening a RFCOMM TTY device, move it to
| the corresponding ACL device as a child. When closing the device,
| move it back to the virtual device tree.
| Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

The simplest fix for this bug is to prevent sysfs_move_dir()
from self-deadlocking when (old_parent == new_parent).

This patch prevents total system lockup when using rfcomm devices.
Signed-off-by: NMark Lord <mlord@pobox.com>
Acked-by: NCornelia Huck <cornelia.huck@de.ibm.com>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Fix the following error if FB_DDC=n

Kernel: arch/x86_64/boot/bzImage is ready  (#1)
  Building modules, stage 2.
  MODPOST 229 modules
WARNING: "fb_ddc_read" [drivers/video/nvidia/nvidiafb.ko] undefined!
make[1]: *** [__modpost] Error 1
Signed-off-by: NAntonino Daplas <adaplas@gmail.com>
Cc: James Simmons <jsimmons@infradead.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Fix implicit declarations and missing code in atyfb.

drivers/video/aty/atyfb_base.c:2137: warning: implicit declaration of function 'a
ty_ld_lcd'
drivers/video/aty/atyfb_base.c:2154: warning: implicit declaration of function 'a
ty_st_lcd'
atyfb_base.c:(.text+0x33e5c): undefined reference to `aty_ld_lcd'
atyfb_base.c:(.text+0x33eb2): undefined reference to `aty_st_lcd'
Signed-off-by: NRandy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: NAntonino Daplas <adaplas@gmail.com>
Cc: James Simmons <jsimmons@infradead.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

drivers/video/nvidia/nv_backlight.c: In function 'nvidia_bl_init':
drivers/video/nvidia/nv_backlight.c:103: error: implicit declaration of function 'pmac_has_backlight_type'
Signed-off-by: NDave Jones <davej@redhat.com>
Signed-off-by: NAntonino Daplas <adaplas@gmail.com>
Cc: James Simmons <jsimmons@infradead.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

arch/i386/kernel/vmi.c: In function 'vmi_safe_halt':
arch/i386/kernel/vmi.c:262: warning: implicit declaration of function 'vmi_stop_hz_timer'
arch/i386/kernel/vmi.c:266: warning: implicit declaration of function 'vmi_account_time_restart_hz_timer'
Acked-by: NIngo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Zachary Amsden <zach@vmware.com>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The programming of periodic tick devices needs to be saved/restored
across suspend/resume - otherwise we might end up with a system coming
up that relies on getting a PIT (or HPET) interrupt, while those devices
default to 'no interrupts' after powerup. (To confuse things it worked
to a certain degree on some systems because the lapic gets initialized
as a side-effect of SMP bootup.)

This suspend / resume thing was dropped unintentionally during the
last-minute -mm code reshuffling.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

CONFIG_PARAVIRT broke old glibc bootup: it silently turned off the
selectability of CONFIG_COMPAT_VDSO and thus rendered distro kernels
unbootable on old-style VDSO glibc setups.

the proper solution is to keep COMPAT_VDSO available - if a hypervisor
needs any modification of that concept then we'll judge those changes in
full context, once those changes are submitted.
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

* 'for-linus' of git://git.o-hand.com/linux-rpurdie-backlight:
  backlight: Allow enable/disable of fb backlights, fixing regressions
  backlight: Fix nvidia backlight initial brightness

there's a new NMI watchdog related problem: KVM crashes on certain
bzImages because ... we enable the NMI watchdog by default (even if the
user does not ask for it) , and no other OS on this planet does that so
KVM doesnt have emulation for that yet. So KVM injects a #GP, which
crashes the Linux guest:

 general protection fault: 0000 [#1]
 PREEMPT SMP
 Modules linked in:
 CPU:    0
 EIP:    0060:[<c011a8ae>]    Not tainted VLI
 EFLAGS: 00000246   (2.6.20-rc5-rt0 #3)
 EIP is at setup_apic_nmi_watchdog+0x26d/0x3d3

and no, i did /not/ request an nmi_watchdog on the boot command line!

Solution: turn off that darn thing! It's a debug tool, not a 'make life
harder' tool!!

with this patch the KVM guest boots up just fine.

And with this my laptop (Lenovo T60) also stopped its sporadic hard
hanging (sometimes in acpi_init(), sometimes later during bootup,
sometimes much later during actual use) as well. It hung with both
nmi_watchdog=1 and nmi_watchdog=2, so it's generally the fact of NMI
injection that is causing problems, not the NMI watchdog variant, nor
any particular bootup code.

[ NMI breaks on some systems, esp in combination with SMM -Arjan ]
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Acked-by: NArjan van de Ven <arjan@linux.intel.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

do not use default=y for CONFIG_VMI (we do not do that for any driver or
special-hardware feature): the overwhelming majority of Linux users does
not need it, and interested users and distributions can enable it
as-needed.
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Clarify the description of the CONFIG_VMI option: describe the reality
that VMI is a VMWare-only interface for now. Once that changes and
another hypervisor adopts the VMI ABI we can change the text.

As can be seen from the Xen paravirtualization patches submitted to lkml
the Xen project has chosen its own, non-VMI interface between Xen and
the para-Linux - so remove Xen from the description.
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Temove the mistaken turning on of NO_IDLE_HZ on x86+PARAVIRT kernels.

It's an obsolete, limited form of dynticks.
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Acked-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

CT based mach64 cards were reported to hang on sparc64 boxes when
compiled with gcc-4.1.x and later.

Looking at this piece of code, it's no surprise.  A critical
delay was implemented as an empty for() loop, and gcc 4.0.x
and previous did not optimize it away, so we did get a delay.

But gcc-4.1.x and later can optimize it away, and we get crashes.

Use a real udelay() to fix this.  Fix verified on SunBlade100.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

  CC      arch/i386/kernel/vmi.o
/home/bunk/linux/kernel-2.6/linux-2.6.21-rc2-mm1/arch/i386/kernel/vmi.c: In function 'vmi_map_pt_hook':
/home/bunk/linux/kernel-2.6/linux-2.6.21-rc2-mm1/arch/i386/kernel/vmi.c:387: error: 'KM_PTE0' undeclared (first use in this function)
/home/bunk/linux/kernel-2.6/linux-2.6.21-rc2-mm1/arch/i386/kernel/vmi.c:387: error: (Each undeclared identifier is reported only once
/home/bunk/linux/kernel-2.6/linux-2.6.21-rc2-mm1/arch/i386/kernel/vmi.c:387: error: for each function it appears in.)
/home/bunk/linux/kernel-2.6/linux-2.6.21-rc2-mm1/arch/i386/kernel/vmi.c:387: error: 'KM_PTE1' undeclared (first use in this function)
make[2]: *** [arch/i386/kernel/vmi.o] Error 1
Signed-off-by: NAdrian Bunk <bunk@stusta.de>
Acked-by: NZachary Amsden <zach@vmware.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Replacing use of UTS_RELEASE with utsname()->release avoids that the
usb-storage driver is recompiled each time the kernel version changes.
Signed-off-by: NSam Ravnborg <sam@ravnborg.org>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add some documentation for the new and very useful io-accounting feature.
It's being added to Documentation/filesystems/proc.txt
Signed-off-by: NRoland Kletzing <devzero@web.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Fix the following compile error:

  MODPOST 327 modules
WARNING: "aty_st_lcd" [drivers/video/aty/atyfb.ko] undefined!
WARNING: "aty_ld_lcd" [drivers/video/aty/atyfb.ko] undefined!
make[1]: *** [__modpost] Error 1
make: *** [modules] Error 2
Signed-off-by: NAntonino Daplas <adaplas@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

"drivers/char/epca.c:2741: warning: 'get_termio' defined but not used"
Signed-off-by: NMichal Piotrowski <michal.k.k.piotrowski@gmail.com>
Acked-by: NAlan Cox <alan@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Doing something like this on a two cpu system

  # echo 0 > /sys/devices/system/cpu/cpu0/online
  # echo 1 > /sys/devices/system/cpu/cpu0/online
  # echo 0 > /sys/devices/system/cpu/cpu1/online

will give me this:

  =======================================================
  [ INFO: possible circular locking dependency detected ]
  2.6.21-rc2-g562aa1d4-dirty #7
  -------------------------------------------------------
  bash/1282 is trying to acquire lock:
   (&cpu_base->lock_key){.+..}, at: [<000000000005f17e>] hrtimer_cpu_notify+0xc6/0x240

  but task is already holding lock:
   (&cpu_base->lock_key#2){.+..}, at: [<000000000005f174>] hrtimer_cpu_notify+0xbc/0x240

  which lock already depends on the new lock.

This happens because we have the following code in kernel/hrtimer.c:

  migrate_hrtimers(int cpu)
  [...]
  old_base = &per_cpu(hrtimer_bases, cpu);
  new_base = &get_cpu_var(hrtimer_bases);
  [...]
  spin_lock(&new_base->lock);
  spin_lock(&old_base->lock);

Which means the spinlocks are taken in an order which depends on which cpu
gets shut down from which other cpu. Therefore lockdep complains that there
might be an ABBA deadlock. Since migrate_hrtimers() gets only called on
cpu hotplug it's safe to assume that it isn't executed concurrently on a

The same problem exists in kernel/timer.c: migrate_timers().

As pointed out by Christian Borntraeger one possible solution to avoid
the locking order complaints would be to make sure that the locks are
always taken in the same order. E.g. by taking the lock of the cpu with
the lower number first.

To achieve this we introduce two new spinlock functions double_spin_lock
and double_spin_unlock which lock or unlock two locks in a given order.

Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Roman Zippel <zippel@linux-m68k.org>
Cc: John Stultz <johnstul@us.ibm.com>
Cc: Christian Borntraeger <cborntra@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This patch resolves the issue found here:
http://bugme.osdl.org/show_bug.cgi?id=7426

The basic summary is:
Currently we register most of i386/x86_64 clocksources at module_init
time. Then we enable clocksource selection at late_initcall time. This
causes some problems for drivers that use gettimeofday for init
calibration routines (specifically the es1968 driver in this case),
where durring module_init, the only clocksource available is the low-res
jiffies clocksource. This may cause slight calibration errors, due to
the small sampling time used.

It should be noted that drivers that require fine grained time may not
function on architectures that do not have better then jiffies
resolution timekeeping (there are a few). However, this does not
discount the reasonable need for such fine-grained timekeeping at init
time.

Thus the solution here is to register clocksources earlier (ideally when
the hardware is being initialized), and then we enable clocksource
selection at fs_initcall (before device_initcall).

This patch should probably get some testing time in -mm, since
clocksource selection is one of the most important issues for correct
timekeeping, and I've only been able to test this on a few of my own
boxes.
Signed-off-by: NJohn Stultz <johnstul@us.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Removes unused 'flags' variable from setup_IO_APIC_irq().
Signed-off-by: NDavid Rientjes <rientjes@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

ipmi_si_intf tries to access default ports, if no device could be found
elsewhere.  On PPC we have a function to check, if these legacy IO ports
are accessible.  This patch adds a check for these ports on PPC.  This
patch fixes a breakage of IPMI module on PPC machines without a BMC.
Signed-off-by: NChristian Krafft <krafft@de.ibm.com>
Acked-by: NMichael Ellerman <michael@ellerman.id.au>
Signed-off-by: NCorey Minyard <minyard@acm.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

- In fact we don't have to fail if AOP_TRUNCATED_PAGE was returned from
  prepare_write or commit_write. It is beter to retry attempt where it
  is possible.

- Rearange ecryptfs_get_lower_page() error handling logic, make it more clean.
Signed-off-by: NDmitriy Monakhov <dmonakhov@openvz.org>
Acked-by: NMichael Halcrow <mhalcrow@us.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

- Currently after path_lookup succeed we dot't have any guarantie what
  it is DIR. This must be explicitly demanded.
- path_lookup can't return negative dentry, So inode check is useless.
Signed-off-by: NDmitriy Monakhov <dmonakhov@openvz.org>
Acked-by: NMichael Halcrow <mhalcrow@us.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

  Testing NMI watchdog ... CPU#0: NMI appears to be stuck (54->54)!
  CPU#1: NMI appears to be stuck (0->0)!

Keep the PIT/HPET alive when nmi_watchdog = 1 is given on the command
line.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Recent patch for raid6 reshape had a change missing that showed up in
subsequent review.

Many places in the raid5 code used "conf->raid_disks-1" to mean "number of
data disks".  With raid6 that had to be changed to "conf->raid_disk -
conf->max_degraded" or similar.  One place was missed.

This bug means that if a raid6 reshape were aborted in the middle the
recorded position would be wrong.  On restart it would either fail (as the
position wasn't on an appropriate boundary) or would leave a section of the
array unreshaped, causing data corruption.
Signed-off-by: NNeil Brown <neilb@suse.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Critical fixes for SMP.

Fix a couple functions which needed to be __devinit and fix a bogus parameter
to AP startup that just so happened to work because the low virtual mapping of
memory was still established.
Signed-off-by: NZachary Amsden <zach@vmware.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Use para_fill instead of directly setting the APIC ops to the result of the
vmi_get_function call - this allows one to implement a VMI ROM without
implementing APIC functions, just using the native APIC functions.

While doing this, I realized that there is a lot more cleanup that should have
been done.  Basically, we should never assume that the ROM implements a
specific set of functions, and always allow fallback to the native
implementation.

This is critical for future compatibility.
Signed-off-by: NAnthony Liguori <anthony@codemonkey.ws>
Signed-off-by: NZachary Amsden <zach@vmware.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

More goo from hrtimers integration.  We do compile and run properly with NO_HZ
enabled.  There was a period when we didn't because of a missing export, but
that was since fixed.

And with the clocksource code now firmly in place, we can get rid of code that
fixes up the wallclock, since this is done in the common infrastructure.  This
actually fixes a timer bug as well, that was caused by do_settimeofday no
longer being callable with interrupts disabled due to the use of
on_each_cpu().
Signed-off-by: NZachary Amsden <zach@vmware.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The time_init_hook in paravirt-ops no longer functions in the correct manner
after the integration of the hrtimers code.  The problem is that now the call
path for time initialization is:

  time_init :
       late_time_init = hpet_time_init;

  late_time_init -> hpet_time_init:
       setup_pit_timer (BAD)
       do_time_init --> (via paravirt.h)
          time_init_hook --> (via arch_hooks.h)
              time_init_hook (in SUBARCH/setup.c)

If this isn't confusing enough, the paravirt case goes through an indirect
function pointer in the paravirt-ops table.  The problem is, by the time the
paravirt hook is called, the pit timer is already enabled.

But paravirt guests have their own timer, and don't want to use the PIT.
Rather than intensify the struggle for power going on here, just make it all
nice and simple and just unconditionally do all timer setup in the
late_time_init hook.  This also has the advantage of enabling timers in the
same place in all code paths, so everyone has the same bugs and we don't have
outliers who break other code because they turn on timer too early or too
late.

So the paravirt-ops time init function is now by default hpet_time_init, which
is the time init function used for native hardware.  Paravirt guests have the
chance to override this when they setup the paravirt-ops table, and should
need no change.
Signed-off-by: NZachary Amsden <zach@vmware.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Not respecting udelay causes problems with any virtual hardware that is passed
through to real hardware.  This can be noticed by any device that interacts
with the real world in real time - like AP startup, which takes real time.  Or
keyboard LEDs, which should blink in real-time.  Or floppy drives, but only
when passed through to a real floppy controller on OSes which can't
sufficiently buffer the floppy commands to emulate a zero latency floppy.  Or
IDE drives, when connecting to a physical CDROM.

This was mostly a hack to get the kernel to boot faster, but it introduced a
number of misvirtualization bugs, and Alan and Pavel argued pretty strongly
against it.  We were the only client, and now want to clean up this cruft.
Signed-off-by: NZachary Amsden <zach@vmware.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>