rt: import 3.4-rc2-rt1

Application of the -rt patch found at:

  http://www.kernel.org/pub/linux/kernel/projects/rt/3.4/patch-3.4-rc2-rt1.patch.bz2

Signed-off-by: Bruce Ashfield <bruce.ashfield@windriver.com>
rt: integrate 3.4-rc2-rt2

Merging 3.4-rc2-rt2 from:

  http://www.kernel.org/pub/linux/kernel/projects/rt/3.4/incr/patch-3.4-rc2-rt1-rt2.patch

Signed-off-by: Bruce Ashfield <bruce.ashfield@windriver.com>
arm_versatile_926ejs: add default nor flash mtd parts

Create default MTD partition tables for versatile and fix the problem
that without partition the integrator map driver will fail to register
mtd device.

Signed-off-by: Tony Liu <Bo.Liu@windriver.com>
arm_versatile_926ejs: kick off PrimeCell RTC PL031

For RTC PL031, need to explicitly set bit "RTC start" of Control
register(RTCCR) to enable it's counting.

Signed-off-by: Tony Liu <Bo.Liu@windriver.com>
slab, lockdep: Annotate all slab caches

Currently we only annotate the kmalloc caches, annotate all of them.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Hans Schillstrom <hans@schillstrom.com>
Cc: Christoph Lameter <cl@gentwo.org>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Matt Mackall <mpm@selenic.com>
Cc: Sitsofe Wheeler <sitsofe@yahoo.com>
Cc: linux-mm@kvack.org
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/n/tip-10bey2cgpcvtbdkgigaoab8w@git.kernel.org
x86: kprobes: Remove remove bogus preempt_enable

The CONFIG_PREEMPT=n section of setup_singlestep() contains:

    preempt_enable_no_resched();

That's bogus as it is asymetric - no preempt_disable() - and it just
never blew up because preempt_enable_no_resched() is a NOP when
CONFIG_PREEMPT=n. Remove it.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
tick: Add tick skew boot option

Let the user decide whether power consumption or jitter is the
more important consideration for their machines.

Quoting removal commit af5ab277ded04bd9bc6b048c5a2f0e7d70ef0867:
    
"Historically, Linux has tried to make the regular timer tick on the
 various CPUs not happen at the same time, to avoid contention on
 xtime_lock.
    
 Nowadays, with the tickless kernel, this contention no longer happens
 since time keeping and updating are done differently. In addition,
 this skew is actually hurting power consumption in a measurable way on
 many-core systems."
    
Problems:
    
    - Contrary to the above, systems do encounter contention on both
      xtime_lock and RCU structure locks when the tick is synchronized.
    
    - Moderate sized RT systems suffer intolerable jitter due to the tick
      being synchronized.
    
    - SGI reports the same for their large systems.
    
    - Fully utilized systems reap no power saving benefit from skew removal,
      but do suffer from resulting induced lock contention.
    
    - 0209f649 rcu: limit rcu_node leaf-level fanout
      This patch was born to combat lock contention which testing showed
      to have been _induced by_ skew removal.  Skew the tick, contention
      disappeared virtually completely.

[ tglx: build fix ]

Signed-off-by: Mike Galbraith <mgalbraith@suse.de>
Link: http://lkml.kernel.org/r/1336472458.21924.78.camel@marge.simpson.net
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
x86: hpet: Disable MSI on Lenovo W510

MSI based per cpu timers lose interrupts when intel_idle() is enabled
- independent of the c-state. With idle=poll the problem cannot be
observed. We have no idea yet, whether this is a W510 specific issue
or a general chipset oddity. Blacklist the known problem machine.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
block: Shorten interrupt disabled regions

Moving the blk_sched_flush_plug() call out of the interrupt/preempt
disabled region in the scheduler allows us to replace
local_irq_save/restore(flags) by local_irq_disable/enable() in
blk_flush_plug().

Now instead of doing this we disable interrupts explicitely when we
lock the request_queue and reenable them when we drop the lock. That
allows interrupts to be handled when the plug list contains requests
for more than one queue.

Aside of that this change makes the scope of the irq disabled region
more obvious. The current code confused the hell out of me when
looking at:

 local_irq_save(flags);
   spin_lock(q->queue_lock);
   ...
   queue_unplugged(q...);
     scsi_request_fn();
       spin_unlock(q->queue_lock);
       spin_lock(shost->host_lock);
       spin_unlock_irq(shost->host_lock);

-------------------^^^ ????

       spin_lock_irq(q->queue_lock);
       spin_unlock(q->lock);
 local_irq_restore(flags);

Also add a comment to __blk_run_queue() documenting that
q->request_fn() can drop q->queue_lock and reenable interrupts, but
must return with q->queue_lock held and interrupts disabled.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/20110622174919.025446432@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
sched: Distangle worker accounting from rq-%3Elock

The worker accounting for cpu bound workers is plugged into the core
scheduler code and the wakeup code. This is not a hard requirement and
can be avoided by keeping track of the state in the workqueue code
itself.

Keep track of the sleeping state in the worker itself and call the
notifier before entering the core scheduler. There might be false
positives when the task is woken between that call and actually
scheduling, but that's not really different from scheduling and being
woken immediately after switching away. There is also no harm from
updating nr_running when the task returns from scheduling instead of
accounting it in the wakeup code.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/20110622174919.135236139@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
mips-enable-interrupts-in-signal.patch

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
arm-enable-interrupts-in-signal-code.patch

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
seqlock: Remove unused functions

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

No point in having different implementations for the same thing.

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

xtime_lock is going to be split apart in mainline, so we can shorten
the seqcount protected regions and avoid updating seqcount in some
code pathes. This is a straight forward split, so we can avoid the
whole mess with raw seqlocks for RT.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
intel_idle: Convert i7300_idle_lock to raw spinlock

24 core Intel box's first exposure to 3.0.12-rt30-rc3 didn't go well.

[   27.104159] i7300_idle: loaded v1.55
[   27.104192] BUG: scheduling while atomic: swapper/2/0/0x00000002
[   27.104309] Pid: 0, comm: swapper/2 Tainted: G           N  3.0.12-rt30-rc3-rt #1
[   27.104317] Call Trace:
[   27.104338]  [<ffffffff810046a5>] dump_trace+0x85/0x2e0
[   27.104372]  [<ffffffff8144eb00>] thread_return+0x12b/0x30b
[   27.104381]  [<ffffffff8144f1b9>] schedule+0x29/0xb0
[   27.104389]  [<ffffffff814506e5>] rt_spin_lock_slowlock+0xc5/0x240
[   27.104401]  [<ffffffffa01f818f>] i7300_idle_notifier+0x3f/0x360 [i7300_idle]
[   27.104415]  [<ffffffff814546c7>] notifier_call_chain+0x37/0x70
[   27.104426]  [<ffffffff81454748>] __atomic_notifier_call_chain+0x48/0x70
[   27.104439]  [<ffffffff81001a39>] cpu_idle+0x89/0xb0
[   27.104449] bad: scheduling from the idle thread!

Signed-off-by: Mike Galbraith <efault@gmx.de>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/1323258522.5057.73.camel@marge.simson.net
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
tracing: Account for preempt off in preempt_schedule()

The preempt_schedule() uses the preempt_disable_notrace() version
because it can cause infinite recursion by the function tracer as
the function tracer uses preempt_enable_notrace() which may call
back into the preempt_schedule() code as the NEED_RESCHED is still
set and the PREEMPT_ACTIVE has not been set yet.

See commit: d1f74e20b5b064a130cd0743a256c2d3cfe84010 that made this
change.

The preemptoff and preemptirqsoff latency tracers require the first
and last preempt count modifiers to enable tracing. But this skips
the checks. Since we can not convert them back to the non notrace
version, we can use the idle() hooks for the latency tracers here.
That is, the start/stop_critical_timings() works well to manually
start and stop the latency tracer for preempt off timings.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Clark Williams <williams@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
signal-revert-ptrace-preempt-magic.patch

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
arm: Mark pmu interupt IRQF_NO_THREAD

PMU interrupt must not be threaded. Remove IRQF_DISABLED while at it
as we run all handlers with interrupts disabled anyway.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
arm: Allow forced irq threading

All timer interrupts and the perf interrupt are marked NO_THREAD, so
its safe to allow forced interrupt threading.

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