Documentation/locking/locktypes: Minor copy editor fixes

Minor editorial fixes:
- remove 'enabled' from PREEMPT_RT enabled kernels for consistency
- add some periods for consistency
- add "'" for possessive CPU's
- spell out interrupts

[ tglx: Picked up Paul's suggestions ]
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Paul E. McKenney <paulmck@kernel.org>
Link: https://lkml.kernel.org/r/ac615f36-0b44-408d-aeab-d76e4241add4@infradead.org

Documentation/locking/locktypes.rst

@@ -84,7 +84,7 @@ rtmutex
 
 RT-mutexes are mutexes with support for priority inheritance (PI).
 
-PI has limitations on non PREEMPT_RT enabled kernels due to preemption and
+PI has limitations on non-PREEMPT_RT kernels due to preemption and
 interrupt disabled sections.
 
 PI clearly cannot preempt preemption-disabled or interrupt-disabled
@@ -150,7 +150,7 @@ kernel configuration including PREEMPT_RT enabled kernels.
 
 raw_spinlock_t is a strict spinning lock implementation in all kernels,
 including PREEMPT_RT kernels.  Use raw_spinlock_t only in real critical
-core code, low level interrupt handling and places where disabling
+core code, low-level interrupt handling and places where disabling
 preemption or interrupts is required, for example, to safely access
 hardware state.  raw_spinlock_t can sometimes also be used when the
 critical section is tiny, thus avoiding RT-mutex overhead.
@@ -160,20 +160,20 @@ spinlock_t
 
 The semantics of spinlock_t change with the state of PREEMPT_RT.
 
-On a non PREEMPT_RT enabled kernel spinlock_t is mapped to raw_spinlock_t
-and has exactly the same semantics.
+On a non-PREEMPT_RT kernel spinlock_t is mapped to raw_spinlock_t and has
+exactly the same semantics.
 
 spinlock_t and PREEMPT_RT
 -------------------------
 
-On a PREEMPT_RT enabled kernel spinlock_t is mapped to a separate
-implementation based on rt_mutex which changes the semantics:
+On a PREEMPT_RT kernel spinlock_t is mapped to a separate implementation
+based on rt_mutex which changes the semantics:
 
- - Preemption is not disabled
+ - Preemption is not disabled.
 
  - The hard interrupt related suffixes for spin_lock / spin_unlock
-   operations (_irq, _irqsave / _irqrestore) do not affect the CPUs
-   interrupt disabled state
+   operations (_irq, _irqsave / _irqrestore) do not affect the CPU's
+   interrupt disabled state.
 
  - The soft interrupt related suffix (_bh()) still disables softirq
    handlers.
@@ -279,8 +279,8 @@ fully preemptible context.  Instead, use spin_lock_irq() or
 spin_lock_irqsave() and their unlock counterparts.  In cases where the
 interrupt disabling and locking must remain separate, PREEMPT_RT offers a
 local_lock mechanism.  Acquiring the local_lock pins the task to a CPU,
-allowing things like per-CPU irq-disabled locks to be acquired.  However,
-this approach should be used only where absolutely necessary.
+allowing things like per-CPU interrupt disabled locks to be acquired.
+However, this approach should be used only where absolutely necessary.
 
 
 raw_spinlock_t