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=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, UNPARSEABLE_RELAY,USER_AGENT_SANE_1 autolearn=unavailable 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 54406FA372B for ; Wed, 16 Oct 2019 15:27:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 388EF2067D for ; Wed, 16 Oct 2019 15:27:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2394123AbfJPP1b (ORCPT ); Wed, 16 Oct 2019 11:27:31 -0400 Received: from out30-45.freemail.mail.aliyun.com ([115.124.30.45]:50564 "EHLO out30-45.freemail.mail.aliyun.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2393605AbfJPP1a (ORCPT ); Wed, 16 Oct 2019 11:27:30 -0400 X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R191e4;CH=green;DM=||false|;FP=0|-1|-1|-1|0|-1|-1|-1;HT=e01e01451;MF=laijs@linux.alibaba.com;NM=1;PH=DS;RN=9;SR=0;TI=SMTPD_---0TfEscsj_1571239583; Received: from C02XQCBJJG5H.local(mailfrom:laijs@linux.alibaba.com fp:SMTPD_---0TfEscsj_1571239583) by smtp.aliyun-inc.com(127.0.0.1); Wed, 16 Oct 2019 23:26:24 +0800 Subject: Re: [PATCH 6/7] rcu: rename some CONFIG_PREEMPTION to CONFIG_PREEMPT_RCU To: paulmck@kernel.org, 20191015102402.1978-1-laijs@linux.alibaba.com Cc: linux-kernel@vger.kernel.org, Lai Jiangshan , Josh Triplett , Steven Rostedt , Mathieu Desnoyers , Joel Fernandes , rcu@vger.kernel.org References: <20191015102850.2079-1-laijs@linux.alibaba.com> <20191015102850.2079-4-laijs@linux.alibaba.com> <20191016035407.GB2689@paulmck-ThinkPad-P72> From: Lai Jiangshan Message-ID: <484d846f-8fbb-ccd2-d66a-a6b48d4a1df4@linux.alibaba.com> Date: Wed, 16 Oct 2019 23:26:23 +0800 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.14; rv:60.0) Gecko/20100101 Thunderbird/60.8.0 MIME-Version: 1.0 In-Reply-To: <20191016035407.GB2689@paulmck-ThinkPad-P72> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2019/10/16 11:54 上午, Paul E. McKenney wrote: > On Tue, Oct 15, 2019 at 10:28:48AM +0000, Lai Jiangshan wrote: >> CONFIG_PREEMPTION and CONFIG_PREEMPT_RCU are always identical, >> but some code depends on CONFIG_PREEMPTION to access to >> rcu_preempt functionalitis. This patch changes CONFIG_PREEMPTION >> to CONFIG_PREEMPT_RCU in these cases. >> >> Signed-off-by: Lai Jiangshan >> Signed-off-by: Lai Jiangshan > > I believe that this does not cause problems with Sebastian's patch > "[PATCH 27/34] rcu: Use CONFIG_PREEMPTION where appropriate", but could > you please check? I don't know for which commit the patch "[PATCH 27/34] rcu: Use CONFIG_PREEMPTION where appropriate" should be applied against after several tries. But I don't think there will be any conflicts which this patch by "eye" applying. Thanks, Lai > > Thanx, Paul > >> --- >> kernel/rcu/tree.c | 4 ++-- >> kernel/rcu/tree_stall.h | 6 +++--- >> 2 files changed, 5 insertions(+), 5 deletions(-) >> >> diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c >> index 7db5ea06a9ed..81eb64fcf5ab 100644 >> --- a/kernel/rcu/tree.c >> +++ b/kernel/rcu/tree.c >> @@ -1926,7 +1926,7 @@ rcu_report_unblock_qs_rnp(struct rcu_node *rnp, unsigned long flags) >> struct rcu_node *rnp_p; >> >> raw_lockdep_assert_held_rcu_node(rnp); >> - if (WARN_ON_ONCE(!IS_ENABLED(CONFIG_PREEMPTION)) || >> + if (WARN_ON_ONCE(!IS_ENABLED(CONFIG_PREEMPT_RCU)) || >> WARN_ON_ONCE(rcu_preempt_blocked_readers_cgp(rnp)) || >> rnp->qsmask != 0) { >> raw_spin_unlock_irqrestore_rcu_node(rnp, flags); >> @@ -2294,7 +2294,7 @@ static void force_qs_rnp(int (*f)(struct rcu_data *rdp)) >> mask = 0; >> raw_spin_lock_irqsave_rcu_node(rnp, flags); >> if (rnp->qsmask == 0) { >> - if (!IS_ENABLED(CONFIG_PREEMPTION) || >> + if (!IS_ENABLED(CONFIG_PREEMPT_RCU) || >> rcu_preempt_blocked_readers_cgp(rnp)) { >> /* >> * No point in scanning bits because they >> diff --git a/kernel/rcu/tree_stall.h b/kernel/rcu/tree_stall.h >> index 0b75426ebb3e..55f9b84790d3 100644 >> --- a/kernel/rcu/tree_stall.h >> +++ b/kernel/rcu/tree_stall.h >> @@ -163,7 +163,7 @@ static void rcu_iw_handler(struct irq_work *iwp) >> // >> // Printing RCU CPU stall warnings >> >> -#ifdef CONFIG_PREEMPTION >> +#ifdef CONFIG_PREEMPT_RCU >> >> /* >> * Dump detailed information for all tasks blocking the current RCU >> @@ -215,7 +215,7 @@ static int rcu_print_task_stall(struct rcu_node *rnp) >> return ndetected; >> } >> >> -#else /* #ifdef CONFIG_PREEMPTION */ >> +#else /* #ifdef CONFIG_PREEMPT_RCU */ >> >> /* >> * Because preemptible RCU does not exist, we never have to check for >> @@ -233,7 +233,7 @@ static int rcu_print_task_stall(struct rcu_node *rnp) >> { >> return 0; >> } >> -#endif /* #else #ifdef CONFIG_PREEMPTION */ >> +#endif /* #else #ifdef CONFIG_PREEMPT_RCU */ >> >> /* >> * Dump stacks of all tasks running on stalled CPUs. First try using >> -- >> 2.20.1 >>