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Violators will be prosecuted; (version=TLSv1/SSLv3 cipher=AES256-GCM-SHA384 bits=256/256) Sun, 11 Nov 2018 19:29:06 -0000 Received: from b01ledav003.gho.pok.ibm.com (b01ledav003.gho.pok.ibm.com [9.57.199.108]) by b01cxnp23034.gho.pok.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id wABJT56g26804236 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Sun, 11 Nov 2018 19:29:05 GMT Received: from b01ledav003.gho.pok.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id D39A5B2065; Sun, 11 Nov 2018 19:29:05 +0000 (GMT) Received: from b01ledav003.gho.pok.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id B2C22B2067; Sun, 11 Nov 2018 19:29:05 +0000 (GMT) Received: from paulmck-ThinkPad-W541 (unknown [9.85.207.24]) by b01ledav003.gho.pok.ibm.com (Postfix) with ESMTP; Sun, 11 Nov 2018 19:29:05 +0000 (GMT) Received: by paulmck-ThinkPad-W541 (Postfix, from userid 1000) id 8E84616C5D9C; Sun, 11 Nov 2018 11:29:06 -0800 (PST) From: "Paul E. McKenney" To: linux-kernel@vger.kernel.org Cc: mingo@kernel.org, jiangshanlai@gmail.com, dipankar@in.ibm.com, akpm@linux-foundation.org, mathieu.desnoyers@efficios.com, josh@joshtriplett.org, tglx@linutronix.de, peterz@infradead.org, rostedt@goodmis.org, dhowells@redhat.com, edumazet@google.com, fweisbec@gmail.com, oleg@redhat.com, joel@joelfernandes.org, Zhouyi Zhou , "Paul E . McKenney" Subject: [PATCH tip/core/rcu 07/14] rcu: Adjust the comment of function rcu_is_watching Date: Sun, 11 Nov 2018 11:28:57 -0800 X-Mailer: git-send-email 2.17.1 In-Reply-To: <20181111192839.GA32144@linux.ibm.com> References: <20181111192839.GA32144@linux.ibm.com> X-TM-AS-GCONF: 00 x-cbid: 18111119-0072-0000-0000-000003C6F2F5 X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00010028; HX=3.00000242; KW=3.00000007; PH=3.00000004; SC=3.00000270; SDB=6.01116014; UDB=6.00577118; IPR=6.00896114; MB=3.00024114; MTD=3.00000008; XFM=3.00000015; UTC=2018-11-11 19:29:11 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 18111119-0073-0000-0000-00004A134333 Message-Id: <20181111192904.3199-7-paulmck@linux.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2018-11-11_13:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=1 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=904 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1807170000 definitions=main-1811110185 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Zhouyi Zhou Because RCU avoids interrupting idle CPUs, rcu_is_watching() is used to test whether or not it is currently legal to run RCU read-side critical sections on this CPU. However, the first sentence and last sentences of current comment for rcu_is_watching have opposite meaning of what is expected. This commit therefore fixes this header comment. Signed-off-by: Zhouyi Zhou Signed-off-by: Paul E. McKenney --- kernel/rcu/tree.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index e7c9848d1e1b..429a46fb087a 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -904,12 +904,12 @@ void rcu_irq_enter_irqson(void) } /** - * rcu_is_watching - see if RCU thinks that the current CPU is idle + * rcu_is_watching - see if RCU thinks that the current CPU is not idle * * Return true if RCU is watching the running CPU, which means that this * CPU can safely enter RCU read-side critical sections. In other words, - * if the current CPU is in its idle loop and is neither in an interrupt - * or NMI handler, return true. + * if the current CPU is not in its idle loop or is in an interrupt or + * NMI handler, return true. */ bool notrace rcu_is_watching(void) { -- 2.17.1