From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id F260BC433F5 for ; Wed, 29 Aug 2018 22:55:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id AA87A2064E for ; Wed, 29 Aug 2018 22:55:50 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org AA87A2064E Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.vnet.ibm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728195AbeH3Cy5 (ORCPT ); Wed, 29 Aug 2018 22:54:57 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:34008 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727316AbeH3CxX (ORCPT ); Wed, 29 Aug 2018 22:53:23 -0400 Received: from pps.filterd (m0098399.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.22/8.16.0.22) with SMTP id w7TMs15R118945 for ; Wed, 29 Aug 2018 18:54:14 -0400 Received: from e17.ny.us.ibm.com (e17.ny.us.ibm.com [129.33.205.207]) by mx0a-001b2d01.pphosted.com with ESMTP id 2m61g7xntq-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Wed, 29 Aug 2018 18:54:14 -0400 Received: from localhost by e17.ny.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Wed, 29 Aug 2018 18:54:13 -0400 Received: from b01cxnp23033.gho.pok.ibm.com (9.57.198.28) by e17.ny.us.ibm.com (146.89.104.204) with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted; (version=TLSv1/SSLv3 cipher=AES256-GCM-SHA384 bits=256/256) Wed, 29 Aug 2018 18:54:08 -0400 Received: from b01ledav003.gho.pok.ibm.com (b01ledav003.gho.pok.ibm.com [9.57.199.108]) by b01cxnp23033.gho.pok.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id w7TMs8xq24969376 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Wed, 29 Aug 2018 22:54:08 GMT Received: from b01ledav003.gho.pok.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id D8508B2067; Wed, 29 Aug 2018 18:53:03 -0400 (EDT) Received: from b01ledav003.gho.pok.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id B930BB2065; Wed, 29 Aug 2018 18:53:03 -0400 (EDT) Received: from paulmck-ThinkPad-W541 (unknown [9.70.82.159]) by b01ledav003.gho.pok.ibm.com (Postfix) with ESMTP; Wed, 29 Aug 2018 18:53:03 -0400 (EDT) Received: by paulmck-ThinkPad-W541 (Postfix, from userid 1000) id B66F316C91DA; Wed, 29 Aug 2018 15:54:07 -0700 (PDT) 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, "Paul E. McKenney" Subject: [PATCH tip/core/rcu 19/24] rcu: Clean up flavor-related definitions and comments in tree_exp.h Date: Wed, 29 Aug 2018 15:54:00 -0700 X-Mailer: git-send-email 2.17.1 In-Reply-To: <20180829225340.GA7019@linux.vnet.ibm.com> References: <20180829225340.GA7019@linux.vnet.ibm.com> X-TM-AS-GCONF: 00 x-cbid: 18082922-0040-0000-0000-00000467593C X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00009636; HX=3.00000242; KW=3.00000007; PH=3.00000004; SC=3.00000266; SDB=6.01080749; UDB=6.00557500; IPR=6.00860735; MB=3.00023002; MTD=3.00000008; XFM=3.00000015; UTC=2018-08-29 22:54:13 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 18082922-0041-0000-0000-0000086E731B Message-Id: <20180829225405.7275-19-paulmck@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2018-08-29_06:,, 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=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1807170000 definitions=main-1808290223 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Signed-off-by: Paul E. McKenney --- kernel/rcu/tree_exp.h | 22 +++++++++++----------- 1 file changed, 11 insertions(+), 11 deletions(-) diff --git a/kernel/rcu/tree_exp.h b/kernel/rcu/tree_exp.h index 060bdb45cd95..78553a8fa3c6 100644 --- a/kernel/rcu/tree_exp.h +++ b/kernel/rcu/tree_exp.h @@ -601,8 +601,8 @@ static void wait_rcu_exp_gp(struct work_struct *wp) } /* - * Given an rcu_state pointer and a smp_call_function() handler, kick - * off the specified flavor of expedited grace period. + * Given a smp_call_function() handler, kick off the specified + * implementation of expedited grace period. */ static void _synchronize_rcu_expedited(smp_call_func_t func) { @@ -721,7 +721,7 @@ static void sync_rcu_exp_handler(void *unused) resched_cpu(rdp->cpu); } -/* PREEMPT=y, so no RCU-sched to clean up after. */ +/* PREEMPT=y, so no PREEMPT=n expedited grace period to clean up after. */ static void sync_sched_exp_online_cleanup(int cpu) { } @@ -798,13 +798,13 @@ static void sync_sched_exp_online_cleanup(int cpu) } /* - * Because a context switch is a grace period for RCU-sched, any blocking - * grace-period wait automatically implies a grace period if there - * is only one CPU online at any point time during execution of either - * synchronize_sched() or synchronize_rcu_bh(). It is OK to occasionally - * incorrectly indicate that there are multiple CPUs online when there - * was in fact only one the whole time, as this just adds some overhead: - * RCU still operates correctly. + * Because a context switch is a grace period for !PREEMPT, any + * blocking grace-period wait automatically implies a grace period if + * there is only one CPU online at any point time during execution of + * either synchronize_rcu() or synchronize_rcu_expedited(). It is OK to + * occasionally incorrectly indicate that there are multiple CPUs online + * when there was in fact only one the whole time, as this just adds some + * overhead: RCU still operates correctly. */ static int rcu_blocking_is_gp(void) { @@ -823,7 +823,7 @@ void synchronize_rcu_expedited(void) RCU_LOCKDEP_WARN(lock_is_held(&rcu_bh_lock_map) || lock_is_held(&rcu_lock_map) || lock_is_held(&rcu_sched_lock_map), - "Illegal synchronize_sched_expedited() in RCU read-side critical section"); + "Illegal synchronize_rcu_expedited() in RCU read-side critical section"); /* If only one CPU, this is automatically a grace period. */ if (rcu_blocking_is_gp()) -- 2.17.1