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

Pull core locking updates from Ingo Molnar:
 "The main updates in this cycle were:

   - mutex MCS refactoring finishing touches: improve comments, refactor
     and clean up code, reduce debug data structure footprint, etc.

   - qrwlock finishing touches: remove old code, self-test updates.

   - small rwsem optimization

   - various smaller fixes/cleanups"

* 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  locking/lockdep: Revert qrwlock recusive stuff
  locking/rwsem: Avoid double checking before try acquiring write lock
  locking/rwsem: Move EXPORT_SYMBOL() lines to follow function definition
  locking/rwlock, x86: Delete unused asm/rwlock.h and rwlock.S
  locking/rwlock, x86: Clean up asm/spinlock*.h to remove old rwlock code
  locking/semaphore: Resolve some shadow warnings
  locking/selftest: Support queued rwlock
  locking/lockdep: Restrict the use of recursive read_lock() with qrwlock
  locking/spinlocks: Always evaluate the second argument of spin_lock_nested()
  locking/Documentation: Update locking/mutex-design.txt disadvantages
  locking/Documentation: Move locking related docs into Documentation/locking/
  locking/mutexes: Use MUTEX_SPIN_ON_OWNER when appropriate
  locking/mutexes: Refactor optimistic spinning code
  locking/mcs: Remove obsolete comment
  locking/mutexes: Document quick lock release when unlocking
  locking/mutexes: Standardize arguments in lock/unlock slowpaths
  locking: Remove deprecated smp_mb__() barriers

9 files changed, 14 insertions, 12 deletions

diff --git a/Documentation/00-INDEX b/Documentation/00-INDEX
index 27e67a98b7be..1750fcef1ab4 100644
--- a/Documentation/00-INDEX
+++ b/Documentation/00-INDEX
@@ -287,6 +287,8 @@ local_ops.txt
 	- semantics and behavior of local atomic operations.
 lockdep-design.txt
 	- documentation on the runtime locking correctness validator.
+locking/
+	- directory with info about kernel locking primitives
 lockstat.txt
 	- info on collecting statistics on locks (and contention).
 lockup-watchdogs.txt
diff --git a/Documentation/DocBook/kernel-locking.tmpl b/Documentation/DocBook/kernel-locking.tmpl
index e584ee12a1e7..7c9cc4846cb6 100644
--- a/Documentation/DocBook/kernel-locking.tmpl
+++ b/Documentation/DocBook/kernel-locking.tmpl
@@ -1972,7 +1972,7 @@ machines due to caching.
    <itemizedlist>
     <listitem>
      <para>
-       <filename>Documentation/spinlocks.txt</filename>: 
+       <filename>Documentation/locking/spinlocks.txt</filename>:
        Linus Torvalds' spinlocking tutorial in the kernel sources.
      </para>
     </listitem>
diff --git a/Documentation/lockdep-design.txt b/Documentation/locking/lockdep-design.txt
index 5dbc99c04f6e..5dbc99c04f6e 100644
--- a/Documentation/lockdep-design.txt
+++ b/Documentation/locking/lockdep-design.txt
diff --git a/Documentation/lockstat.txt b/Documentation/locking/lockstat.txt
index 72d010689751..7428773a1e69 100644
--- a/Documentation/lockstat.txt
+++ b/Documentation/locking/lockstat.txt
@@ -12,7 +12,7 @@ Because things like lock contention can severely impact performance.
 - HOW
 
 Lockdep already has hooks in the lock functions and maps lock instances to
-lock classes. We build on that (see Documentation/lockdep-design.txt).
+lock classes. We build on that (see Documentation/lokcing/lockdep-design.txt).
 The graph below shows the relation between the lock functions and the various
 hooks therein.
 
diff --git a/Documentation/mutex-design.txt b/Documentation/locking/mutex-design.txt
index ee231ed09ec6..60c482df1a38 100644
--- a/Documentation/mutex-design.txt
+++ b/Documentation/locking/mutex-design.txt
@@ -145,9 +145,9 @@ Disadvantages
 
 Unlike its original design and purpose, 'struct mutex' is larger than
 most locks in the kernel. E.g: on x86-64 it is 40 bytes, almost twice
-as large as 'struct semaphore' (24 bytes) and 8 bytes shy of the
-'struct rw_semaphore' variant. Larger structure sizes mean more CPU
-cache and memory footprint.
+as large as 'struct semaphore' (24 bytes) and tied, along with rwsems,
+for the largest lock in the kernel. Larger structure sizes mean more
+CPU cache and memory footprint.
 
 When to use mutexes
 -------------------
diff --git a/Documentation/rt-mutex-design.txt b/Documentation/locking/rt-mutex-design.txt
index 8666070d3189..8666070d3189 100644
--- a/Documentation/rt-mutex-design.txt
+++ b/Documentation/locking/rt-mutex-design.txt
diff --git a/Documentation/rt-mutex.txt b/Documentation/locking/rt-mutex.txt
index 243393d882ee..243393d882ee 100644
--- a/Documentation/rt-mutex.txt
+++ b/Documentation/locking/rt-mutex.txt
diff --git a/Documentation/spinlocks.txt b/Documentation/locking/spinlocks.txt
index 97eaf5727178..ff35e40bdf5b 100644
--- a/Documentation/spinlocks.txt
+++ b/Documentation/locking/spinlocks.txt
@@ -105,9 +105,9 @@ never used in interrupt handlers, you can use the non-irq versions:
 	spin_unlock(&lock);
 
 (and the equivalent read-write versions too, of course). The spinlock will
-guarantee the same kind of exclusive access, and it will be much faster. 
+guarantee the same kind of exclusive access, and it will be much faster.
 This is useful if you know that the data in question is only ever
-manipulated from a "process context", ie no interrupts involved. 
+manipulated from a "process context", ie no interrupts involved.
 
 The reasons you mustn't use these versions if you have interrupts that
 play with the spinlock is that you can get deadlocks:
@@ -122,21 +122,21 @@ the other interrupt happens on another CPU, but it is _not_ ok if the
 interrupt happens on the same CPU that already holds the lock, because the
 lock will obviously never be released (because the interrupt is waiting
 for the lock, and the lock-holder is interrupted by the interrupt and will
-not continue until the interrupt has been processed). 
+not continue until the interrupt has been processed).
 
 (This is also the reason why the irq-versions of the spinlocks only need
 to disable the _local_ interrupts - it's ok to use spinlocks in interrupts
 on other CPU's, because an interrupt on another CPU doesn't interrupt the
 CPU that holds the lock, so the lock-holder can continue and eventually
-releases the lock). 
+releases the lock).
 
 Note that you can be clever with read-write locks and interrupts. For
 example, if you know that the interrupt only ever gets a read-lock, then
 you can use a non-irq version of read locks everywhere - because they
-don't block on each other (and thus there is no dead-lock wrt interrupts. 
-But when you do the write-lock, you have to use the irq-safe version. 
+don't block on each other (and thus there is no dead-lock wrt interrupts.
+But when you do the write-lock, you have to use the irq-safe version.
 
-For an example of being clever with rw-locks, see the "waitqueue_lock" 
+For an example of being clever with rw-locks, see the "waitqueue_lock"
 handling in kernel/sched/core.c - nothing ever _changes_ a wait-queue from
 within an interrupt, they only read the queue in order to know whom to
 wake up. So read-locks are safe (which is good: they are very common
diff --git a/Documentation/ww-mutex-design.txt b/Documentation/locking/ww-mutex-design.txt
index 8a112dc304c3..8a112dc304c3 100644
--- a/Documentation/ww-mutex-design.txt
+++ b/Documentation/locking/ww-mutex-design.txt