Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S938259AbdDSQq5 (ORCPT ); Wed, 19 Apr 2017 12:46:57 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:49091 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S937130AbdDSQqp (ORCPT ); Wed, 19 Apr 2017 12:46:45 -0400 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, bobby.prani@gmail.com, "Paul E. McKenney" Subject: [PATCH v3 tip/core/rcu 03/11] types: Update obsolete callback_head comment Date: Wed, 19 Apr 2017 09:46:29 -0700 X-Mailer: git-send-email 2.5.2 In-Reply-To: <20170419164553.GA10874@linux.vnet.ibm.com> References: <20170419164553.GA10874@linux.vnet.ibm.com> X-TM-AS-GCONF: 00 x-cbid: 17041916-0056-0000-0000-00000343A7CC X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00006939; HX=3.00000240; KW=3.00000007; PH=3.00000004; SC=3.00000208; SDB=6.00849678; UDB=6.00419581; IPR=6.00628312; BA=6.00005304; NDR=6.00000001; ZLA=6.00000005; ZF=6.00000009; ZB=6.00000000; ZP=6.00000000; ZH=6.00000000; ZU=6.00000002; MB=3.00015095; XFM=3.00000013; UTC=2017-04-19 16:46:41 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 17041916-0057-0000-0000-00000779B9C3 Message-Id: <1492620397-12313-3-git-send-email-paulmck@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:,, definitions=2017-04-19_14:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 suspectscore=1 malwarescore=0 phishscore=0 adultscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1703280000 definitions=main-1704190139 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1030 Lines: 25 The comment header for callback_head (and thus for rcu_head) states that the bottom two bits of a pointer to these structures must be zero. This is obsolete: The new requirement is that only the bottom bit need be zero. This commit therefore updates this comment. Signed-off-by: Paul E. McKenney --- include/linux/types.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/include/linux/types.h b/include/linux/types.h index 1e7bd24848fc..258099a4ed82 100644 --- a/include/linux/types.h +++ b/include/linux/types.h @@ -209,7 +209,7 @@ struct ustat { * naturally due ABI requirements, but some architectures (like CRIS) have * weird ABI and we need to ask it explicitly. * - * The alignment is required to guarantee that bits 0 and 1 of @next will be + * The alignment is required to guarantee that bit 0 of @next will be * clear under normal conditions -- as long as we use call_rcu(), * call_rcu_bh(), call_rcu_sched(), or call_srcu() to queue callback. * -- 2.5.2