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McKenney" , Steven Rostedt , pantin@google.com Subject: [PATCH RFC 2/5] doc: rcu: Add more rationale for using rcu_read_lock_sched in checklist Date: Fri, 5 Oct 2018 16:18:11 -0700 Message-Id: <20181005231815.170433-3-joel@joelfernandes.org> X-Mailer: git-send-email 2.19.0.605.g01d371f741-goog In-Reply-To: <20181005231815.170433-1-joel@joelfernandes.org> References: <20181005231815.170433-1-joel@joelfernandes.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org It could be clarified better why rcu_read_lock_sched is better than using preempt_disable, add the same. Signed-off-by: Joel Fernandes (Google) --- Documentation/RCU/checklist.txt | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/Documentation/RCU/checklist.txt b/Documentation/RCU/checklist.txt index 49747717d905..8860ab2a897a 100644 --- a/Documentation/RCU/checklist.txt +++ b/Documentation/RCU/checklist.txt @@ -63,7 +63,7 @@ over a rather long period of time, but improvements are always welcome! pointer must be covered by rcu_read_lock(), rcu_read_lock_bh(), rcu_read_lock_sched(), or by the appropriate update-side lock. Disabling of preemption can serve as rcu_read_lock_sched(), but - is less readable. + is less readable and prevents lockdep from detecting locking issues. Letting RCU-protected pointers "leak" out of an RCU read-side critical section is every bid as bad as letting them leak out -- 2.19.0.605.g01d371f741-goog