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authorSebastian Andrzej Siewior <bigeasy@linutronix.de>2020-12-15 15:16:49 +0100
committerPaul E. McKenney <paulmck@kernel.org>2021-01-06 16:10:44 -0800
commit81ad58be2f83f9bd675f67ca5b8f420358ddf13c (patch)
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parent361c0f3d80dc3b54c20a19e8ffa2ad728fc1d23d (diff)
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doc: Use CONFIG_PREEMPTION
CONFIG_PREEMPTION is selected by CONFIG_PREEMPT and by CONFIG_PREEMPT_RT. Both PREEMPT and PREEMPT_RT require the same functionality which today depends on CONFIG_PREEMPT. Update the documents and mention CONFIG_PREEMPTION. Spell out CONFIG_PREEMPT_RT (instead PREEMPT_RT) since it is an option now. Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Diffstat (limited to 'Documentation/RCU/rcubarrier.rst')
-rw-r--r--Documentation/RCU/rcubarrier.rst6
1 files changed, 3 insertions, 3 deletions
diff --git a/Documentation/RCU/rcubarrier.rst b/Documentation/RCU/rcubarrier.rst
index f64f4413a47c..3b4a24877496 100644
--- a/Documentation/RCU/rcubarrier.rst
+++ b/Documentation/RCU/rcubarrier.rst
@@ -9,7 +9,7 @@ RCU (read-copy update) is a synchronization mechanism that can be thought
of as a replacement for read-writer locking (among other things), but with
very low-overhead readers that are immune to deadlock, priority inversion,
and unbounded latency. RCU read-side critical sections are delimited
-by rcu_read_lock() and rcu_read_unlock(), which, in non-CONFIG_PREEMPT
+by rcu_read_lock() and rcu_read_unlock(), which, in non-CONFIG_PREEMPTION
kernels, generate no code whatsoever.
This means that RCU writers are unaware of the presence of concurrent
@@ -329,10 +329,10 @@ Answer: This cannot happen. The reason is that on_each_cpu() has its last
to smp_call_function() and further to smp_call_function_on_cpu(),
causing this latter to spin until the cross-CPU invocation of
rcu_barrier_func() has completed. This by itself would prevent
- a grace period from completing on non-CONFIG_PREEMPT kernels,
+ a grace period from completing on non-CONFIG_PREEMPTION kernels,
since each CPU must undergo a context switch (or other quiescent
state) before the grace period can complete. However, this is
- of no use in CONFIG_PREEMPT kernels.
+ of no use in CONFIG_PREEMPTION kernels.
Therefore, on_each_cpu() disables preemption across its call
to smp_call_function() and also across the local call to