Documentation: RCU: Correct spelling

Correct spelling problems for Documentation/RCU/ as reported
by codespell.

Note: in RTFP.txt, there are other misspellings that are left as is
since they were used that way in email Subject: lines or in LWN.net
articles. [preemptable, Preemptable, synchonisation]

Acked-by: Joel Fernandes (Google) <[e-mail]>
Signed-off-by: Randy Dunlap <[e-mail]>
Cc: Jonathan Corbet <[e-mail]>
Cc: [e-mail]
Cc: "Paul E. McKenney" <[e-mail]>
Cc: Frederic Weisbecker <[e-mail]>
Cc: Neeraj Upadhyay <[e-mail]>
Cc: Josh Triplett <[e-mail]>
Cc: [e-mail]
Signed-off-by: Paul E. McKenney <[e-mail]>
Signed-off-by: Joel Fernandes (Google) <[e-mail]>

Documentation/RCU/Design/Expedited-Grace-Periods/Expedited-Grace-Periods.rst

···
 
 Again, only one request in a given batch need actually carry out a
 grace-period operation, which means there must be an efficient way to
-identify which of many concurrent reqeusts will initiate the grace
+identify which of many concurrent requests will initiate the grace
 period, and that there be an efficient way for the remaining requests to
 wait for that grace period to complete. However, that is the topic of
 the next section.
···
 In earlier implementations, the task requesting the expedited grace
 period also drove it to completion. This straightforward approach had
 the disadvantage of needing to account for POSIX signals sent to user
-tasks, so more recent implemementations use the Linux kernel's
+tasks, so more recent implementations use the Linux kernel's
 workqueues (see Documentation/core-api/workqueue.rst).
 
 The requesting task still does counter snapshotting and funnel-lock
···
 initialized, which does not happen until some time after the scheduler
 spawns the first task. Given that there are parts of the kernel that
 really do want to execute grace periods during this mid-boot “dead
-zone”, expedited grace periods must do something else during thie time.
+zone”, expedited grace periods must do something else during this time.
 
 What they do is to fall back to the old practice of requiring that the
 requesting task drive the expedited grace period, as was the case before

Documentation/RCU/Design/Memory-Ordering/Tree-RCU-Memory-Ordering.rst

···
 +-----------------------------------------------------------------------+
 
 The approach must be extended to handle one final case, that of waking a
-task blocked in ``synchronize_rcu()``. This task might be affinitied to
+task blocked in ``synchronize_rcu()``. This task might be affined to
 a CPU that is not yet aware that the grace period has ended, and thus
 might not yet be subject to the grace period's memory ordering.
 Therefore, there is an ``smp_mb()`` after the return from

Documentation/RCU/RTFP.txt

···
 In 2012, Josh Triplett received his Ph.D. with his dissertation
 covering RCU-protected resizable hash tables and the relationship
 between memory barriers and read-side traversal order:  If the updater
-is making changes in the opposite direction from the read-side traveral
+is making changes in the opposite direction from the read-side traversal
 order, the updater need only execute a memory-barrier instruction,
 but if in the same direction, the updater needs to wait for a grace
 period between the individual updates [JoshTriplettPhD].  Also in 2012,
···
 [Viewed September 5, 2005]"
 ,annotation={
 	First posting showing how RCU can be safely adapted for
-	preemptable RCU read side critical sections.
+	preemptible RCU read side critical sections.
 }
 }
 
···
 \url{https://lore.kernel.org/r/[e-mail]}
 [Viewed October 25, 2007]"
 ,annotation={
-	Final patch for preemptable RCU to -rt.  (Later patches were
+	Final patch for preemptible RCU to -rt.  (Later patches were
 	to mainline, eventually incorporated.)
 }
 }
···
 \url{https://lore.kernel.org/r/[e-mail]}
 [Viewed August 15, 2009]"
 ,annotation={
-	First posting of simple and fast preemptable RCU.
+	First posting of simple and fast preemptible RCU.
 }
 }
 
···
 	RCU-protected hash tables, barriers vs. read-side traversal order.
 	.
 	If the updater is making changes in the opposite direction from
-	the read-side traveral order, the updater need only execute a
+	the read-side traversal order, the updater need only execute a
 	memory-barrier instruction, but if in the same direction, the
 	updater needs to wait for a grace period between the individual
 	updates.

Documentation/RCU/UP.rst

···
 
 Quick Quiz #3:
 	Why can't synchronize_rcu() return immediately on UP systems running
-	preemptable RCU?
+	preemptible RCU?
 
 .. _answer_quick_quiz_up:
 
···
 
 Answer to Quick Quiz #3:
 	Why can't synchronize_rcu() return immediately on UP systems
-	running preemptable RCU?
+	running preemptible RCU?
 
 	Because some other task might have been preempted in the middle
 	of an RCU read-side critical section.  If synchronize_rcu()

Documentation/RCU/lockdep.rst

···
 	rcu_access_pointer(p):
 		Return the value of the pointer and omit all barriers,
 		but retain the compiler constraints that prevent duplicating
-		or coalescsing.  This is useful when testing the
+		or coalescing.  This is useful when testing the
 		value of the pointer itself, for example, against NULL.
 
 The rcu_dereference_check() check expression can be any boolean

Documentation/RCU/torture.rst

···
 rcutorture's module parameters.  For example, to test a change to RCU's
 CPU stall-warning code, use "--bootargs 'rcutorture.stall_cpu=30'".
 This will of course result in the scripting reporting a failure, namely
-the resuling RCU CPU stall warning.  As noted above, reducing memory may
+the resulting RCU CPU stall warning.  As noted above, reducing memory may
 require disabling rcutorture's callback-flooding tests::
 
 	kvm.sh --cpus 448 --configs '56*TREE04' --memory 128M \
···
 		tools/testing/selftests/rcutorture/res/2022.11.03-11.26.28-remote \
 		--duration 24h
 
-In this case, most of the kvm-again.sh parmeters may be supplied following
+In this case, most of the kvm-again.sh parameters may be supplied following
 the pathname of the old run-results directory.