I'd like to use printk_ratelimit() in NMI context, but it's not
robust right now due to spinlock usage in lib/ratelimit.c. If an
NMI is unlucky enough to hit just that spot we might lock up trying
to take the spinlock again.

Fix that by using a trylock variant. If we contend on that lock we
can genuinely skip the message because the state is just being
accessed by another CPU (or by this CPU).

( We could use atomics for the suppressed messages field, but
  i doubt it matters in practice and it makes the code heavier. )

Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: David S. Miller <davem@davemloft.net>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

I'd like to use printk_ratelimit() in atomic context, but that's
not possible right now due to the spinlock usage this commit
introduced more than a year ago:

  717115e1: printk ratelimiting rewrite

As a first step push the lock into the ratelimit state structure.
This allows us to deal with locking failures to be considered as an
event related to that state being too busy.

Also clean up the code a bit (without changing functionality):

 - tidy up the definitions

 - clean up the code flow

This also shrinks the code a tiny bit:

   text	   data	    bss	    dec	    hex	filename
    264	      0	      4	    268	    10c	ratelimit.o.before
    255	      0	      0	    255	     ff	ratelimit.o.after

( Whole-kernel data size got a bit larger, because we have
  two ratelimit-state data structures right now. )

Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: David S. Miller <davem@davemloft.net>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

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

* 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  rcu: Fix whitespace inconsistencies
  rcu: Fix thinko, actually initialize full tree
  rcu: Apply results of code inspection of kernel/rcutree_plugin.h
  rcu: Add WARN_ON_ONCE() consistency checks covering state transitions
  rcu: Fix synchronize_rcu() for TREE_PREEMPT_RCU
  rcu: Simplify rcu_read_unlock_special() quiescent-state accounting
  rcu: Add debug checks to TREE_PREEMPT_RCU for premature grace periods
  rcu: Kconfig help needs to say that TREE_PREEMPT_RCU scales down
  rcutorture: Occasionally delay readers enough to make RCU force_quiescent_state
  rcu: Initialize multi-level RCU grace periods holding locks
  rcu: Need to update rnp->gpnum if preemptable RCU is to be reliable

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

* 'perfcounters-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  perf_counter, powerpc, sparc: Fix compilation after perf_counter_overflow() change
  perf_counter: x86: Fix PMU resource leak
  perf util: SVG performance improvements
  perf util: Make the timechart SVG width dynamic
  perf timechart: Show the duration of scheduler delays in the SVG
  perf timechart: Show the name of the waker/wakee in timechart

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: Simplify sys_sched_rr_get_interval() system call
  sched: Fix potential NULL derference of doms_cur
  sched: Fix raciness in runqueue_is_locked()
  sched: Re-add lost cpu_allowed check to sched_fair.c::select_task_rq_fair()
  sched: Remove unneeded indentation in sched_fair.c::place_entity()

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:
  kernel/profile.c: Switch /proc/irq/prof_cpu_mask to seq_file
  tracing: Export trace_profile_buf symbols
  tracing/events: use list_for_entry_continue
  tracing: remove max_tracer_type_len
  function-graph: use ftrace_graph_funcs directly
  tracing: Remove markers
  tracing: Allocate the ftrace event profile buffer dynamically
  tracing: Factorize the events profile accounting

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: Print the hypervisor returned tsc_khz during boot
  x86: Correct segment permission flags in 64-bit linker script
  x86: cpuinit-annotate SMP boot trampolines properly
  x86: Increase timeout for EHCI debug port reset completion in early printk
  x86: Fix uaccess_32.h typo
  x86: Trivial whitespace cleanups
  x86, apic: Fix missed handling of discrete apics
  x86/i386: Remove duplicated #include
  x86, mtrr: Convert loop to a while based construct, avoid naked semicolon
  Revert 'x86: Fix system crash when loading with "reservetop" parameter'
  x86, mce: Fix compile warning in case of CONFIG_SMP=n
  x86, apic: Use logical flat on intel with <= 8 logical cpus
  x86: SGI UV: Map MMIO-High memory range
  x86: SGI UV: Add volatile semantics to macros that access chipset registers
  x86: SGI UV: Fix IPI macros
  x86: apic: Convert BUG() to BUG_ON()
  x86: Remove final bits of CONFIG_X86_OLD_MCE

* 'writeback' of git://git.kernel.dk/linux-2.6-block:
  nfs: initialize the backing_dev_info when creating the server
  writeback: make balance_dirty_pages() gradually back more off
  writeback: don't use schedule_timeout() without setting runstate
  nfs: nfs_kill_super() should call bdi_unregister() after killing super

* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-2.6: (222 commits)
  V4L/DVB (13033): pt1: Don't use a deprecated DMA_BIT_MASK macro
  V4L/DVB (13029): radio-si4713: remove #include <linux/version.h>
  V4L/DVB (13027): go7007: convert printks to v4l2_info
  V4L/DVB (13026): s2250-board: Implement brightness and contrast controls
  V4L/DVB (13025): s2250-board: Fix memory leaks
  V4L/DVB (13024): go7007: Implement vidioc_g_std and vidioc_querystd
  V4L/DVB (13023): go7007: Merge struct gofh and go declarations
  V4L/DVB (13022): go7007: Fix mpeg controls
  V4L/DVB (13021): go7007: Fix whitespace and line lengths
  V4L/DVB (13020): go7007: Updates to Kconfig and Makefile
  V4L/DVB (13019): video: initial support for ADV7180
  V4L/DVB (13018): kzalloc failure ignored in au8522_probe()
  V4L/DVB (13017): gspca: kmalloc failure ignored in sd_start()
  V4L/DVB (13016): kmalloc failure ignored in lgdt3304_attach() and s921_attach()
  V4L/DVB (13015): kmalloc failure ignored in m920x_firmware_download()
  V4L/DVB (13014): Add support for Compro VideoMate E800 (DVB-T part only)
  V4L/DVB (13013): FM TX: si4713: Kconfig: Fixed two typos.
  V4L/DVB (13012): uvc: introduce missing kfree
  V4L/DVB (13011): Change tuner type of BeholdTV cards
  V4L/DVB (13009): gspca - stv06xx-hdcs: Reduce exposure range
  ...

* 'linux-next' of git://git.infradead.org/ubifs-2.6:
  UBIFS: fix debugging dump
  UBIFS: improve lprops dump
  UBIFS: various minor commentary fixes
  UBIFS: improve journal head debugging prints
  UBIFS: define journal head numbers in ubifs-media.h
  UBIFS: amend commentaries
  UBIFS: check ubifs_scan error codes better
  UBIFS: do not print scary error messages needlessly
  UBIFS: add inode size debugging check
  UBIFS: constify file and inode operations
  UBIFS: remove unneeded call from ubifs_sync_fs
  UBIFS: kill BKL
  UBIFS: remove unused functions
  UBIFS: suppress compilation warning

* 'linux-next' of git://git.infradead.org/ubi-2.6:
  UBI: improve NOR flash erasure quirk
  UBI: introduce flash dump helper
  UBI: eliminate possible undefined behaviour
  UBI: print a warning if too many PEBs are corrupted
  UBI: amend NOR flash pre-erase quirk
  UBI: print a message if ECH is corrupted and VIDH is ok

* 'drm-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/airlied/drm-2.6: (133 commits)
  drm/vgaarb: add VGA arbitration support to the drm and kms.
  drm/radeon: some r420s have a CP race with the DMA engine.
  drm/radeon/r600/kms: rv670 is not DCE3
  drm/radeon/kms: r420 idle after programming GA_ENHANCE
  drm/radeon/kms: more fixes to rv770 suspend/resume path.
  drm/radeon/kms: more alignment for rv770.c with r600.c
  drm/radeon/kms: rv770 blit init called too late.
  drm/radeon/kms: move around new init path code to avoid posting at init
  drm/radeon/r600: fix some issues with suspend/resume.
  drm/radeon/kms: disable VGA rendering engine before taking over VRAM
  drm/radeon/kms: Move radeon_get_clock_info() call out of radeon_clocks_init().
  drm/radeon/kms: add initial connector properties
  drm/radeon/kms: Use surfaces for scanout / cursor byte swapping on big endian.
  drm/radeon/kms: don't fail if we fail to init GPU acceleration
  drm/r600/kms: fixup number of loops per blit calculation.
  drm/radeon/kms: reprogram format in set base.
  drm/radeon: avivo chips have no separate int bit for display
  drm/radeon/r600: don't do interrupts
  drm: fix _DRM_GEM addmap error message
  drm: update crtc x/y when only fb changes
  ...

Fixed up trivial conflicts in firmware/Makefile due to network driver
(cxgb3) and drm (mga/r128/radeon) firmware being listed next to each
other.

The build of the dabusb driver broke:

  drivers/media/video/dabusb.c:758: error: unknown field 'nodename' specified in initializer
  drivers/media/video/dabusb.c:758: warning: initialization from incompatible pointer type
  make[3]: *** wait: No child processes.  Stop.

Due to this commit:

  e454cea2: Driver-Core: extend devnode callbacks to provide permissions

Missing the dabusb driver's dabusb_nodename() callback.

Similar issues with the iio/industrialio driver in staging, pointed out
and patched by Jean Delvare.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Industrialio-parts-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

NFS may free the server structure without ever having used the
bdi, so we either need to flag the bdi as being uninitialized or
initialize it up front. This does the latter.

This fixes a crash with mounting more than one NFS file system,
should people ever need that kind of obscure NFS functionality.
Tested-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

Currently it just sleeps for a very short time, just 1 jiffy. If
we keep looping in there, continually delay for a little longer
of up to 100msec in total. That was the old limit for congestion
wait.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

Just use schedule_timeout_interruptible(), saves a call to
set_current_state().
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

Otherwise we could be attempting to flush data for a writeback
thread and bdi that have already disappeared.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6 into linux-next

Conflicts:
	fs/ubifs/super.c

Merge the upstream tree in order to resolve a conflict with the
per-bdi writeback changes from the linux-2.6-block tree.

By removing the need for it to know details of scheduling classes.

This allows PlugSched to define orthogonal scheduling classes.
Signed-off-by: Peter Williams <pwil3058@bigpond.net.au>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
LKML-Reference: <06d1b89ee15a0eef82d7.1253496713@mudlark.pw.nest>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Commit 5622f295 ("x86, perf_counter, bts: Optimize BTS overflow
handling") removed the regs field from struct perf_sample_data and
added a regs parameter to perf_counter_overflow().  This breaks the
build on powerpc (and Sparc) as reported by Sachin Sant:

  arch/powerpc/kernel/perf_counter.c: In function 'record_and_restart':
  arch/powerpc/kernel/perf_counter.c:1165: error: unknown field 'regs' specified in initializer

This adjusts arch/powerpc/kernel/perf_counter.c to correspond with the
new struct perf_sample_data and perf_counter_overflow().

[ v2: also fix Sparc, Markus Metzger <markus.t.metzger@intel.com> ]
Reported-by: Sachin Sant <sachinp@in.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Cc: Markus Metzger <markus.t.metzger@intel.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: benh@kernel.crashing.org
Cc: linuxppc-dev@ozlabs.org
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <19127.8400.376239.586120@drongo.ozlabs.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

VGA arb requires DRM support for non-kms drivers, to turn on/off
irqs when disabling the mem/io regions.

VGA arb requires KMS support for GPUs where we can turn off VGA
decoding. Currently we know how to do this for intel and radeon
kms drivers, which allows them to be removed from the arbiter.

This patch comes from Fedora rawhide kernel.
Signed-off-by: Dave Airlie <airlied@redhat.com>

This patch makes sure the CP doesn't DMA do VRAM while 2D
is active by inserting a CP resync token.

todo: port to kms.
Signed-off-by: Dave Airlie <airlied@redhat.com>

RV670 was using the wrong modesetting code.
Signed-off-by: Alex Deucher <alexdeucher@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

https://bugs.freedesktop.org/show_bug.cgi?id=24041

The idle allows rs690 to startup properly.
Signed-off-by: Dave Airlie <airlied@redhat.com>

This resumes my
RV730PRO (4650)
RV770 (4850)
fine.

Still researching the RV4550 (RV710), resumes without X fine.
Signed-off-by: Dave Airlie <airlied@redhat.com>

* git://git.kernel.org/pub/scm/linux/kernel/git/jaswinder/linux-2.6:
  includecheck fix: x86, cpu/common.c
  includecheck fix: kernel/trace, ring_buffer.c
  includecheck fix: include/linux, ftrace.h
  includecheck fix: include/linux, page_cgroup.h
  includecheck fix: include/linux, aio.h
  includecheck fix: include/drm, drm_memory.h
  includecheck fix: include/acpi, acpi_bus.h
  includecheck fix: drivers/xen, evtchn.c
  includecheck fix: drivers/video, vgacon.c
  includecheck fix: drivers/scsi, ibmvscsi.c
  includecheck fix: drivers/scsi, libfcoe.c
  includecheck fix: x86, shadow.c
  includecheck fix: x86, traps.c
  includecheck fix: um, helper.c
  includecheck fix: s390, sys_s390.c

Ingo points out that I screwed up when merging the 'timers-for-linus'
branch in commit a03fdb76.

A bit too much copy-and-pasting caused the end result to have an
extraneous 'return' in the middle of an expression.  That was obviously
bogus.  Blush.

Reported-by-with-patch: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

* 'next-i2c' of git://aeryn.fluff.org.uk/bjdooks/linux:
  [PATCH] i2c-imx: make bus available early
  i2c-mv64xxx: correct mv64xxx_i2c_intr() return type

* git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core-2.6:
  Driver-Core: extend devnode callbacks to provide permissions

* git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty-2.6: (79 commits)
  USB serial: update the console driver
  usb-serial: straighten out serial_open
  usb-serial: add missing tests and debug lines
  usb-serial: rename subroutines
  usb-serial: fix termios initialization logic
  usb-serial: acquire references when a new tty is installed
  usb-serial: change logic of serial lookups
  usb-serial: put subroutines in logical order
  usb-serial: change referencing of port and serial structures
  tty: Char: mxser, use THRE for ASPP_OQUEUE ioctl
  tty: Char: mxser, add support for CP112UL
  uartlite: support shared interrupt lines
  tty: USB: serial/mct_u232, fix tty refcnt
  tty: riscom8, fix tty refcnt
  tty: riscom8, fix shutdown declaration
  TTY: fix typos
  tty: Power: fix suspend vt regression
  tty: vt: use printk_once
  tty: handle VT specific compat ioctls in vt driver
  n_tty: move echoctl check and clean up logic
  ...

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

* 'perfcounters-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (58 commits)
  perf_counter: Fix perf_copy_attr() pointer arithmetic
  perf utils: Use a define for the maximum length of a trace event
  perf: Add timechart help text and add timechart to "perf help"
  tracing, x86, cpuidle: Move the end point of a C state in the power tracer
  perf utils: Be consistent about minimum text size in the svghelper
  perf timechart: Add "perf timechart record"
  perf: Add the timechart tool
  perf: Add a SVG helper library file
  tracing, perf: Convert the power tracer into an event tracer
  perf: Add a sample_event type to the event_union
  perf: Allow perf utilities to have "callback" options without arguments
  perf: Store trace event name/id pairs in perf.data
  perf: Add a timestamp to fork events
  sched_clock: Make it NMI safe
  perf_counter: Fix up swcounter throttling
  x86, perf_counter, bts: Optimize BTS overflow handling
  perf sched: Add --input=file option to builtin-sched.c
  perf trace: Sample timestamp and cpu when using record flag
  perf tools: Increase MAX_EVENT_LENGTH
  perf tools: Fix memory leak in read_ftrace_printk()
  ...

On an AMD-64 system the processor frequency that is printed during
system boot, may be different than the tsc frequency that was
returned by the hypervisor, due to the value returned from
calibrate_cpu.

For debugging timekeeping or other related issues it might be
better to get the tsc_khz value returned by the hypervisor.

The patch below now prints the tsc frequency that the VMware
hypervisor returned.
Signed-off-by: Alok N Kataria <akataria@vmware.com>
LKML-Reference: <1252095219.12518.13.camel@ank32.eng.vmware.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Merge reason: Bring in changes that the next patch will depend on.
Signed-off-by: Ingo Molnar <mingo@elte.hu>

While these don't get actively used (afaict), it still doesn't hurt
for them to properly reflect what how respective segments will get
mapped/ accessed.
Signed-off-by: Jan Beulich <jbeulich@novell.com>
LKML-Reference: <4AA0E95F0200007800013707@vpn.id2.novell.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Add missing annotations, and make use of include/linux/init.h's
macros.
Signed-off-by: Jan Beulich <jbeulich@novell.com>
LKML-Reference: <4AA0E8F60200007800013703@vpn.id2.novell.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

On one of my systems, several thousand iterations are needed before
CMD_RESET can be observed clear after setting it. Using a much
higher value here obviously cannot hurt.
Signed-off-by: Jan Beulich <jbeulich@novell.com>
Cc: Yinghai Lu <yhlu.kernel@gmail.com>
LKML-Reference: <4AA0E85D02000078000136F9@vpn.id2.novell.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

If CONFIG_CPUMASK_OFFSTACK is enabled but doms_cur alloc failed in
arch_init_sched_domains(), doms_cur will move back to
fallback_doms. But this time, fallback_doms has not been
initialized yet.
Signed-off-by: Yong Zhang <yong.zhang0@gmail.com>
Cc: a.p.zijlstra@chello.nl
LKML-Reference: <1252930816-7672-1-git-send-email-yong.zhang0@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Trivial: correct "that the we don't" typo.
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
LKML-Reference: <20090917125401.GU3717@localdomain.by>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com>
Cc: Vegard Nossum <vegardno@ifi.uio.no>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Alok N Kataria <akataria@vmware.com>
Cc: "Tan Wei Chong" <wei.chong.tan@intel.com>
Cc: Len Brown <len.brown@intel.com>
Cc: Lin Ming <ming.m.lin@intel.com>
Cc: Bob Moore <robert.moore@intel.com>
LKML-Reference: <1253137123-18047-2-git-send-email-felipe.contreras@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

In case of discrete (pretty old) apics we may have cpu_has_apic bit
not set but have to check if smp_found_config (MP spec) is there
and apic was not disabled.

Also don't forget to print apic/io-apic for such case as well.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: "Maciej W. Rozycki" <macro@linux-mips.org>
Cc: Yinghai Lu <yinghai@kernel.org>
LKML-Reference: <20090915071230.GA10604@lenovo>
Signed-off-by: Ingo Molnar <mingo@elte.hu>