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[106.167.171.201]) by smtp.gmail.com with ESMTPSA id x10-20020a17090a294a00b00218b8f8af91sm946469pjf.48.2022.11.23.01.23.12 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 23 Nov 2022 01:23:14 -0800 (PST) Message-ID: Date: Wed, 23 Nov 2022 18:23:09 +0900 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.4.2 Content-Language: en-US To: "Paul E. McKenney" Cc: rcu@vger.kernel.org, linux-kernel@vger.kernel.org, Akira Yokosawa , linux-doc@vger.kernel.org From: Akira Yokosawa Subject: [PATCH 1/2] docs/RCU/rcubarrier: Adjust 'Answer' parts of QQs as definition-lists Precedence: bulk List-ID: X-Mailing-List: rcu@vger.kernel.org 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 --- Documentation/RCU/rcubarrier.rst | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) base-commit: 741cfda870057958c53f9cb0b21ac33f531baaf4 diff --git a/Documentation/RCU/rcubarrier.rst b/Documentation/RCU/rcubarrier.rst index 5a643e5233d5..9fb9ed777355 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