tracing: Fix wraparound problems in "uptime" trace clock

The "uptime" trace clock added in:

commit 8aacf017b065a805d27467843490c976835eb4a5
tracing: Add "uptime" trace clock that uses jiffi

tracing: Fix wraparound problems in "uptime" trace clock

The "uptime" trace clock added in:

commit 8aacf017b065a805d27467843490c976835eb4a5
tracing: Add "uptime" trace clock that uses jiffies

has wraparound problems when the system has been up more
than 1 hour 11 minutes and 34 seconds. It converts jiffies
to nanoseconds using:
(u64)jiffies_to_usecs(jiffy) * 1000ULL
but since jiffies_to_usecs() only returns a 32-bit value, it
truncates at 2^32 microseconds. An additional problem on 32-bit
systems is that the argument is "unsigned long", so fixing the
return value only helps until 2^32 jiffies (49.7 days on a HZ=1000
system).

Avoid these problems by using jiffies_64 as our basis, and
not converting to nanoseconds (we do convert to clock_t because
user facing API must not be dependent on internal kernel
HZ values).

Link: http://lkml.kernel.org/p/99d63c5bfe9b320a3b428d773825a37095bf6a51.1405708254.git.tony.luck@intel.com

Cc: stable@vger.kernel.org # 3.10+
Fixes: 8aacf017b065 "tracing: Add "uptime" trace clock that uses jiffies"
Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

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Merge branch 'next' into for-linus

Prepare first set of updates for 3.11 merge window.

Merge branch 'for-next' of git://github.com/rydberg/linux into next

Pull in changes from Henrik: "a trivial MT documentation fix".

Merge branch 'master' into for-next

Merge tag 'v3.10-rc2' into drm-intel-next-queued

Backmerge Linux 3.10-rc2 since the various (rather trivial) conflicts
grew a bit out of hand. intel_dp.c has the only real functional
conflict since

Merge tag 'v3.10-rc2' into drm-intel-next-queued

Backmerge Linux 3.10-rc2 since the various (rather trivial) conflicts
grew a bit out of hand. intel_dp.c has the only real functional
conflict since the logic changed while dev_priv->edp.bpp was moved
around.

Also squash in a whitespace fixup from Ben Widawsky for
i915_gem_gtt.c, git seems to do something pretty strange in there
(which I don't fully understand tbh).

Conflicts:
drivers/gpu/drm/i915/i915_reg.h
drivers/gpu/drm/i915/intel_dp.c

Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

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Merge tag 'v3.10-rc1' into patchwork

Linux 3.10-rc1

* tag 'v3.10-rc1': (11697 commits)
Linux 3.10-rc1
[SCSI] qla2xxx: Update firmware link in Kconfig file.
[SCSI] iscsi class, qla4xxx: fix se

Merge tag 'v3.10-rc1' into patchwork

Linux 3.10-rc1

* tag 'v3.10-rc1': (11697 commits)
Linux 3.10-rc1
[SCSI] qla2xxx: Update firmware link in Kconfig file.
[SCSI] iscsi class, qla4xxx: fix sess/conn refcounting when find fns are used
[SCSI] sas: unify the pointlessly separated enums sas_dev_type and sas_device_type
[SCSI] pm80xx: thermal, sas controller config and error handling update
[SCSI] pm80xx: NCQ error handling changes
[SCSI] pm80xx: WWN Modification for PM8081/88/89 controllers
[SCSI] pm80xx: Changed module name and debug messages update
[SCSI] pm80xx: Firmware flash memory free fix, with addition of new memory region for it
[SCSI] pm80xx: SPC new firmware changes for device id 0x8081 alone
[SCSI] pm80xx: Added SPCv/ve specific hardware functionalities and relevant changes in common files
[SCSI] pm80xx: MSI-X implementation for using 64 interrupts
[SCSI] pm80xx: Updated common functions common for SPC and SPCv/ve
[SCSI] pm80xx: Multiple inbound/outbound queue configuration
[SCSI] pm80xx: Added SPCv/ve specific ids, variables and modify for SPC
[SCSI] lpfc: fix up Kconfig dependencies
[SCSI] Handle MLQUEUE busy response in scsi_send_eh_cmnd
dm cache: set config value
dm cache: move config fns
dm thin: generate event when metadata threshold passed
...

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Merge tag 'v3.10-rc1' into stable/for-linus-3.10

Linux 3.10-rc1

* tag 'v3.10-rc1': (12273 commits)
Linux 3.10-rc1
[SCSI] qla2xxx: Update firmware link in Kconfig file.
[SCSI] iscsi class, qla

Merge tag 'v3.10-rc1' into stable/for-linus-3.10

Linux 3.10-rc1

* tag 'v3.10-rc1': (12273 commits)
Linux 3.10-rc1
[SCSI] qla2xxx: Update firmware link in Kconfig file.
[SCSI] iscsi class, qla4xxx: fix sess/conn refcounting when find fns are used
[SCSI] sas: unify the pointlessly separated enums sas_dev_type and sas_device_type
[SCSI] pm80xx: thermal, sas controller config and error handling update
[SCSI] pm80xx: NCQ error handling changes
[SCSI] pm80xx: WWN Modification for PM8081/88/89 controllers
[SCSI] pm80xx: Changed module name and debug messages update
[SCSI] pm80xx: Firmware flash memory free fix, with addition of new memory region for it
[SCSI] pm80xx: SPC new firmware changes for device id 0x8081 alone
[SCSI] pm80xx: Added SPCv/ve specific hardware functionalities and relevant changes in common files
[SCSI] pm80xx: MSI-X implementation for using 64 interrupts
[SCSI] pm80xx: Updated common functions common for SPC and SPCv/ve
[SCSI] pm80xx: Multiple inbound/outbound queue configuration
[SCSI] pm80xx: Added SPCv/ve specific ids, variables and modify for SPC
[SCSI] lpfc: fix up Kconfig dependencies
[SCSI] Handle MLQUEUE busy response in scsi_send_eh_cmnd
dm cache: set config value
dm cache: move config fns
dm thin: generate event when metadata threshold passed
...

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Merge branch 'linus' into core/urgent

Update with Linus tree so fixes for the same can be applied.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc

Merge sparc bug fixes that didn't make it into v3.9 into
sparc-next.

Signed-off-by: David S. Miller <davem@davemloft.net>

Merge commit '8700c95adb03' into timers/nohz

The full dynticks tree needs the latest RCU and sched
upstream updates in order to fix some dependencies.

Merge a common upstream merge point that has t

Merge commit '8700c95adb03' into timers/nohz

The full dynticks tree needs the latest RCU and sched
upstream updates in order to fix some dependencies.

Merge a common upstream merge point that has these
updates.

Conflicts:
include/linux/perf_event.h
kernel/rcutree.h
kernel/rcutree_plugin.h

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>

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Merge branch 'next' into for-linus

Prepare first set of updates for 3.10 merge window.

Merge tag 'trace-3.10' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing updates from Steven Rostedt:
"Along with the usual minor fixes and clean ups there are a few

Merge tag 'trace-3.10' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing updates from Steven Rostedt:
"Along with the usual minor fixes and clean ups there are a few major
changes with this pull request.

1) Multiple buffers for the ftrace facility

This feature has been requested by many people over the last few
years. I even heard that Google was about to implement it themselves.
I finally had time and cleaned up the code such that you can now
create multiple instances of the ftrace buffer and have different
events go to different buffers. This way, a low frequency event will
not be lost in the noise of a high frequency event.

Note, currently only events can go to different buffers, the tracers
(ie function, function_graph and the latency tracers) still can only
be written to the main buffer.

2) The function tracer triggers have now been extended.

The function tracer had two triggers. One to enable tracing when a
function is hit, and one to disable tracing. Now you can record a
stack trace on a single (or many) function(s), take a snapshot of the
buffer (copy it to the snapshot buffer), and you can enable or disable
an event to be traced when a function is hit.

3) A perf clock has been added.

A "perf" clock can be chosen to be used when tracing. This will cause
ftrace to use the same clock as perf uses, and hopefully this will
make it easier to interleave the perf and ftrace data for analysis."

* tag 'trace-3.10' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (82 commits)
tracepoints: Prevent null probe from being added
tracing: Compare to 1 instead of zero for is_signed_type()
tracing: Remove obsolete macro guard _TRACE_PROFILE_INIT
ftrace: Get rid of ftrace_profile_bits
tracing: Check return value of tracing_init_dentry()
tracing: Get rid of unneeded key calculation in ftrace_hash_move()
tracing: Reset ftrace_graph_filter_enabled if count is zero
tracing: Fix off-by-one on allocating stat->pages
kernel: tracing: Use strlcpy instead of strncpy
tracing: Update debugfs README file
tracing: Fix ftrace_dump()
tracing: Rename trace_event_mutex to trace_event_sem
tracing: Fix comment about prefix in arch_syscall_match_sym_name()
tracing: Convert trace_destroy_fields() to static
tracing: Move find_event_field() into trace_events.c
tracing: Use TRACE_MAX_PRINT instead of constant
tracing: Use pr_warn_once instead of open coded implementation
ring-buffer: Add ring buffer startup selftest
tracing: Bring Documentation/trace/ftrace.txt up to date
tracing: Add "perf" trace_clock
...

Conflicts:
kernel/trace/ftrace.c
kernel/trace/trace.c

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Merge remote-tracking branch 'efi/chainsaw' into x86/efi

Resolved Conflicts:
drivers/firmware/efivars.c
fs/efivarsfs/file.c

Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>

Merge commit '31d9adca82ce65e5c99d045b5fd917c702b6fce3' into tmp

Conflicts:
arch/arm/plat-omap/dmtimer.c

Merge tag 'v3.9-rc3' into drm-intel-next-queued

Backmerge so that I can merge Imre Deak's coalesced sg entries fixes,
which depend upon the new for_each_sg_page introduce in

commit a321e91b6d73ed01

Merge tag 'v3.9-rc3' into drm-intel-next-queued

Backmerge so that I can merge Imre Deak's coalesced sg entries fixes,
which depend upon the new for_each_sg_page introduce in

commit a321e91b6d73ed011ffceed384c40d2785cf723b
Author: Imre Deak <imre.deak@intel.com>
Date: Wed Feb 27 17:02:56 2013 -0800

lib/scatterlist: add simple page iterator

The merge itself is just two trivial conflicts:

Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

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Merge tag 'v3.9-rc3' into v4l_for_linus

Linux 3.9-rc3

* tag 'v3.9-rc3': (11231 commits)
Linux 3.9-rc3
perf,x86: fix link failure for non-Intel configs
perf,x86: fix wrmsr_on_cpu() warning on

Merge tag 'v3.9-rc3' into v4l_for_linus

Linux 3.9-rc3

* tag 'v3.9-rc3': (11231 commits)
Linux 3.9-rc3
perf,x86: fix link failure for non-Intel configs
perf,x86: fix wrmsr_on_cpu() warning on suspend/resume
Btrfs: fix warning of free_extent_map
perf,x86: fix kernel crash with PEBS/BTS after suspend/resume
ALSA: hda - Fix missing EAPD/GPIO setup for Cirrus codecs
sound: sequencer: cap array index in seq_chn_common_event()
mfd: twl4030-madc: Remove __exit_p annotation
ALSA: hda/ca0132 - Remove extra setting of dsp_state.
ALSA: hda/ca0132 - Check download state of DSP.
ALSA: hda/ca0132 - Check if dspload_image succeeded.
mm/fremap.c: fix possible oops on error path
list: Fix double fetch of pointer in hlist_entry_safe()
Btrfs: fix warning when creating snapshots
Btrfs: return as soon as possible when edquot happens
Btrfs: return EIO if we have extent tree corruption
btrfs: use rcu_barrier() to wait for bdev puts at unmount
Btrfs: remove btrfs_try_spin_lock
Btrfs: get better concurrency for snapshot-aware defrag work
hwmon: (pmbus/ltc2978) Fix temperature reporting
...

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Merge branch 'master' into for-next

Sync with Linus' tree to be able to apply patch to the newly
added ITG-3200 driver.

Merge tag 'v3.9-rc3' into next

Merge with mainline to bring in module_platform_driver_probe() and
devm_ioremap_resource().

tracing: Add "uptime" trace clock that uses jiffies

Add a simple trace clock called "uptime" for those that are
interested in the uptime of the trace. It uses jiffies as that's
the safest method, as

tracing: Add "uptime" trace clock that uses jiffies

Add a simple trace clock called "uptime" for those that are
interested in the uptime of the trace. It uses jiffies as that's
the safest method, as other uptime clocks grab seq locks, which could
cause a deadlock if taken from an event or function tracer.

Requested-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

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Merge tag 'v3.9-rc2' into next

Sync with Linus.

Linux 3.9-rc2

Merge branch 'master' into queue

* master: (15791 commits)
Linux 3.9-rc1
btrfs/raid56: Add missing #include <linux/vmalloc.h>
fix compat_sys_rt_sigprocmask()
SUNRPC: One line comment fix
e

Merge branch 'master' into queue

* master: (15791 commits)
Linux 3.9-rc1
btrfs/raid56: Add missing #include <linux/vmalloc.h>
fix compat_sys_rt_sigprocmask()
SUNRPC: One line comment fix
ext4: enable quotas before orphan cleanup
ext4: don't allow quota mount options when quota feature enabled
ext4: fix a warning from sparse check for ext4_dir_llseek
ext4: convert number of blocks to clusters properly
ext4: fix possible memory leak in ext4_remount()
jbd2: fix ERR_PTR dereference in jbd2__journal_start
metag: Provide dma_get_sgtable()
metag: prom.h: remove declaration of metag_dt_memblock_reserve()
metag: copy devicetree to non-init memory
metag: cleanup metag_ksyms.c includes
metag: move mm/init.c exports out of metag_ksyms.c
metag: move usercopy.c exports out of metag_ksyms.c
metag: move setup.c exports out of metag_ksyms.c
metag: move kick.c exports out of metag_ksyms.c
metag: move traps.c exports out of metag_ksyms.c
metag: move irq enable out of irqflags.h on SMP
...

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

Conflicts:
arch/x86/kernel/kvmclock.c

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Merge tag 'v3.9-rc1' into staging/for_v3.9

Linux 3.9-rc1

* tag 'v3.9-rc1': (10698 commits)
Linux 3.9-rc1
btrfs/raid56: Add missing #include <linux/vmalloc.h>
fix compat_sys_rt_sigprocmask()

Merge tag 'v3.9-rc1' into staging/for_v3.9

Linux 3.9-rc1

* tag 'v3.9-rc1': (10698 commits)
Linux 3.9-rc1
btrfs/raid56: Add missing #include <linux/vmalloc.h>
fix compat_sys_rt_sigprocmask()
SUNRPC: One line comment fix
ext4: enable quotas before orphan cleanup
ext4: don't allow quota mount options when quota feature enabled
ext4: fix a warning from sparse check for ext4_dir_llseek
ext4: convert number of blocks to clusters properly
ext4: fix possible memory leak in ext4_remount()
jbd2: fix ERR_PTR dereference in jbd2__journal_start
metag: Provide dma_get_sgtable()
metag: prom.h: remove declaration of metag_dt_memblock_reserve()
metag: copy devicetree to non-init memory
metag: cleanup metag_ksyms.c includes
metag: move mm/init.c exports out of metag_ksyms.c
metag: move usercopy.c exports out of metag_ksyms.c
metag: move setup.c exports out of metag_ksyms.c
metag: move kick.c exports out of metag_ksyms.c
metag: move traps.c exports out of metag_ksyms.c
metag: move irq enable out of irqflags.h on SMP
...

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

Conflicts:
include/linux/ssb/ssb_driver_gige.h

Also resolves a logical merge confl

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

Conflicts:
include/linux/ssb/ssb_driver_gige.h

Also resolves a logical merge conflict in drivers/net/ethernet/broadcom/-
bgmac.c due to change of an API.

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

Pull perf changes from Ingo Molnar:
"There are lots of improvements, the biggest changes are:

Main ker

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

Pull perf changes from Ingo Molnar:
"There are lots of improvements, the biggest changes are:

Main kernel side changes:

- Improve uprobes performance by adding 'pre-filtering' support, by
Oleg Nesterov.

- Make some POWER7 events available in sysfs, equivalent to what was
done on x86, from Sukadev Bhattiprolu.

- tracing updates by Steve Rostedt - mostly misc fixes and smaller
improvements.

- Use perf/event tracing to report PCI Express advanced errors, by
Tony Luck.

- Enable northbridge performance counters on AMD family 15h, by Jacob
Shin.

- This tracing commit:

tracing: Remove the extra 4 bytes of padding in events

changes the ABI. All involved parties (PowerTop in particular)
seem to agree that it's safe to do now with the introduction of
libtraceevent, but the devil is in the details ...

Main tooling side changes:

- Add 'event group view', from Namyung Kim:

To use it, 'perf record' should group events when recording. And
then perf report parses the saved group relation from file header
and prints them together if --group option is provided. You can
use the 'perf evlist' command to see event group information:

$ perf record -e '{ref-cycles,cycles}' noploop 1
[ perf record: Woken up 2 times to write data ]
[ perf record: Captured and wrote 0.385 MB perf.data (~16807 samples) ]

$ perf evlist --group
{ref-cycles,cycles}

With this example, default perf report will show you each event
separately.

You can use --group option to enable event group view:

$ perf report --group
...
# group: {ref-cycles,cycles}
# ========
# Samples: 7K of event 'anon group { ref-cycles, cycles }'
# Event count (approx.): 6876107743
#
# Overhead Command Shared Object Symbol
# ................ ....... ................. ..........................
99.84% 99.76% noploop noploop [.] main
0.07% 0.00% noploop ld-2.15.so [.] strcmp
0.03% 0.00% noploop [kernel.kallsyms] [k] timerqueue_del
0.03% 0.03% noploop [kernel.kallsyms] [k] sched_clock_cpu
0.02% 0.00% noploop [kernel.kallsyms] [k] account_user_time
0.01% 0.00% noploop [kernel.kallsyms] [k] __alloc_pages_nodemask
0.00% 0.00% noploop [kernel.kallsyms] [k] native_write_msr_safe
0.00% 0.11% noploop [kernel.kallsyms] [k] _raw_spin_lock
0.00% 0.06% noploop [kernel.kallsyms] [k] find_get_page
0.00% 0.02% noploop [kernel.kallsyms] [k] rcu_check_callbacks
0.00% 0.02% noploop [kernel.kallsyms] [k] __current_kernel_time

As you can see the Overhead column now contains both of ref-cycles
and cycles and header line shows group information also - 'anon
group { ref-cycles, cycles }'. The output is sorted by period of
group leader first.

- Initial GTK+ annotate browser, from Namhyung Kim.

- Add option for runtime switching perf data file in perf report,
just press 's' and a menu with the valid files found in the current
directory will be presented, from Feng Tang.

- Add support to display whole group data for raw columns, from Jiri
Olsa.

- Add per processor socket count aggregation in perf stat, from
Stephane Eranian.

- Add interval printing in 'perf stat', from Stephane Eranian.

- 'perf test' improvements

- Add support for wildcards in tracepoint system name, from Jiri
Olsa.

- Add anonymous huge page recognition, from Joshua Zhu.

- perf build-id cache now can show DSOs present in a perf.data file
that are not in the cache, to integrate with build-id servers being
put in place by organizations such as Fedora.

- perf top now shares more of the evsel config/creation routines with
'record', paving the way for further integration like 'top'
snapshots, etc.

- perf top now supports DWARF callchains.

- Fix mmap limitations on 32-bit, fix from David Miller.

- 'perf bench numa mem' NUMA performance measurement suite

- ... and lots of fixes, performance improvements, cleanups and other
improvements I failed to list - see the shortlog and git log for
details."

* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (270 commits)
perf/x86/amd: Enable northbridge performance counters on AMD family 15h
perf/hwbp: Fix cleanup in case of kzalloc failure
perf tools: Fix build with bison 2.3 and older.
perf tools: Limit unwind support to x86 archs
perf annotate: Make it to be able to skip unannotatable symbols
perf gtk/annotate: Fail early if it can't annotate
perf gtk/annotate: Show source lines with gray color
perf gtk/annotate: Support multiple event annotation
perf ui/gtk: Implement basic GTK2 annotation browser
perf annotate: Fix warning message on a missing vmlinux
perf buildid-cache: Add --update option
uprobes/perf: Avoid uprobe_apply() whenever possible
uprobes/perf: Teach trace_uprobe/perf code to use UPROBE_HANDLER_REMOVE
uprobes/perf: Teach trace_uprobe/perf code to pre-filter
uprobes/perf: Teach trace_uprobe/perf code to track the active perf_event's
uprobes: Introduce uprobe_apply()
perf: Introduce hw_perf_event->tp_target and ->tp_list
uprobes/perf: Always increment trace_uprobe->nhit
uprobes/tracing: Kill uprobe_trace_consumer, embed uprobe_consumer into trace_uprobe
uprobes/tracing: Introduce is_trace_uprobe_enabled()
...

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

Pull RCU changes from Ingo Molnar:
"SRCU changes:

- These include debugging aids, updates that move to

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

Pull RCU changes from Ingo Molnar:
"SRCU changes:

- These include debugging aids, updates that move towards the goal of
permitting srcu_read_lock() and srcu_read_unlock() to be used from
idle and offline CPUs, and a few small fixes.

Changes to rcutorture and to RCU documentation:

- Posted to LKML at https://lkml.org/lkml/2013/1/26/188

Enhancements to uniprocessor handling in tiny RCU:

- Posted to LKML at https://lkml.org/lkml/2013/1/27/2

Tag RCU callbacks with grace-period number to simplify callback
advancement:

- Posted to LKML at https://lkml.org/lkml/2013/1/26/203

Miscellaneous fixes:

- Posted to LKML at https://lkml.org/lkml/2013/1/26/204"

* 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (27 commits)
srcu: use ACCESS_ONCE() to access sp->completed in srcu_read_lock()
srcu: Update synchronize_srcu_expedited()'s comments
srcu: Update synchronize_srcu()'s comments
srcu: Remove checks preventing idle CPUs from calling srcu_read_lock()
srcu: Remove checks preventing offline CPUs from calling srcu_read_lock()
srcu: Simple cleanup for cleanup_srcu_struct()
srcu: Add might_sleep() annotation to synchronize_srcu()
srcu: Simplify __srcu_read_unlock() via this_cpu_dec()
rcu: Allow rcutorture to be built at low optimization levels
rcu: Make rcutorture's shuffler task shuffle recently added tasks
rcu: Allow TREE_PREEMPT_RCU on UP systems
rcu: Provide RCU CPU stall warnings for tiny RCU
context_tracking: Add comments on interface and internals
rcu: Remove obsolete Kconfig option from comment
rcu: Remove unused code originally used for context tracking
rcu: Consolidate debugging Kconfig options
rcu: Correct 'optimized' to 'optimize' in header comment
rcu: Trace callback acceleration
rcu: Tag callback lists with corresponding grace-period number
rcutorture: Don't compare ptr with 0
...

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