From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755112Ab3CRUzi (ORCPT ); Mon, 18 Mar 2013 16:55:38 -0400 Received: from e38.co.us.ibm.com ([32.97.110.159]:56809 "EHLO e38.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753344Ab3CRUzf (ORCPT ); Mon, 18 Mar 2013 16:55:35 -0400 From: "Paul E. McKenney" To: linux-kernel@vger.kernel.org Cc: mingo@elte.hu, laijs@cn.fujitsu.com, dipankar@in.ibm.com, akpm@linux-foundation.org, mathieu.desnoyers@polymtl.ca, josh@joshtriplett.org, niv@us.ibm.com, tglx@linutronix.de, peterz@infradead.org, rostedt@goodmis.org, Valdis.Kletnieks@vt.edu, dhowells@redhat.com, edumazet@google.com, darren@dvhart.com, fweisbec@gmail.com, sbw@mit.edu, "Paul E. McKenney" Subject: [PATCH tip/core/rcu 1/2] rcu: Make bugginess of code sample more evident Date: Mon, 18 Mar 2013 13:55:07 -0700 Message-Id: <1363640108-15508-1-git-send-email-paulmck@linux.vnet.ibm.com> X-Mailer: git-send-email 1.8.1.5 X-TM-AS-MML: No X-Content-Scanned: Fidelis XPS MAILER x-cbid: 13031820-5518-0000-0000-00000CA80A88 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: "Paul E. McKenney" One of the code samples in whatisRCU.txt shows a bug, but someone scanning the document quickly might mistake it for a valid use of RCU. Add some screaming comments to help keep speed-readers on track. Reported-by: Nathan Zimmer Signed-off-by: Paul E. McKenney Acked-by: Rafael J. Wysocki --- Documentation/RCU/whatisRCU.txt | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/Documentation/RCU/whatisRCU.txt b/Documentation/RCU/whatisRCU.txt index 0cc7820..10df0b8 100644 --- a/Documentation/RCU/whatisRCU.txt +++ b/Documentation/RCU/whatisRCU.txt @@ -265,9 +265,9 @@ rcu_dereference() rcu_read_lock(); p = rcu_dereference(head.next); rcu_read_unlock(); - x = p->address; + x = p->address; /* BUG!!! */ rcu_read_lock(); - y = p->data; + y = p->data; /* BUG!!! */ rcu_read_unlock(); Holding a reference from one RCU read-side critical section -- 1.8.1.5