From: Akira Yokosawa <akiyks@xxxxxxxxx> The "Answer" parts of QQs divert from proper format of definition-lists as described at [1] and are not rendered as such. Adjust them. Link: [1] https://docutils.sourceforge.io/docs/ref/rst/restructuredtext.html#definition-lists Signed-off-by: Akira Yokosawa <akiyks@xxxxxxxxx> Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxx> --- Documentation/RCU/rcubarrier.rst | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/Documentation/RCU/rcubarrier.rst b/Documentation/RCU/rcubarrier.rst index 5a643e5233d5f..9fb9ed7773552 100644 --- a/Documentation/RCU/rcubarrier.rst +++ b/Documentation/RCU/rcubarrier.rst @@ -296,7 +296,8 @@ Quick Quiz #1: Is there any other situation where rcu_barrier() might be required? -Answer: Interestingly enough, rcu_barrier() was not originally +Answer: + Interestingly enough, rcu_barrier() was not originally implemented for module unloading. Nikita Danilov was using RCU in a filesystem, which resulted in a similar situation at filesystem-unmount time. Dipankar Sarma coded up rcu_barrier() @@ -315,7 +316,8 @@ Quick Quiz #2: Why doesn't line 8 initialize rcu_barrier_cpu_count to zero, thereby avoiding the need for lines 9 and 10? -Answer: Suppose that the on_each_cpu() function shown on line 8 was +Answer: + Suppose that the on_each_cpu() function shown on line 8 was delayed, so that CPU 0's rcu_barrier_func() executed and the corresponding grace period elapsed, all before CPU 1's rcu_barrier_func() started executing. This would result in @@ -351,7 +353,8 @@ Quick Quiz #3: are delayed for a full grace period? Couldn't this result in rcu_barrier() returning prematurely? -Answer: This cannot happen. The reason is that on_each_cpu() has its last +Answer: + This cannot happen. The reason is that on_each_cpu() has its last argument, the wait flag, set to "1". This flag is passed through to smp_call_function() and further to smp_call_function_on_cpu(), causing this latter to spin until the cross-CPU invocation of -- 2.31.1.189.g2e36527f23
