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=-13.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT 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 9E175C433E6 for ; Mon, 31 Aug 2020 18:11:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7B2B52068E for ; Mon, 31 Aug 2020 18:11:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1598897509; bh=Md1F4JPJeRjrVLa/O8zZqOK+IKqCvmD2zTJEeJk3ut8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=I4cj98G0Tzm5TyuJiNnst6+8+PIBvXnom3OqbDUI/QD8PQKa0wd+j/tvBaIINImaU cnh9WrLqBLPERFZSCHWx6rqMWJo8Gdq2Hl1mmMhf6E9eStUcSBrmAar/5ABA4rRNRU yhkhThqBq1ChH/h5V0TZJ8SGfpb8m/cZdwVEdbos= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729574AbgHaSLr (ORCPT ); Mon, 31 Aug 2020 14:11:47 -0400 Received: from mail.kernel.org ([198.145.29.99]:36240 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729325AbgHaSL1 (ORCPT ); Mon, 31 Aug 2020 14:11:27 -0400 Received: from paulmck-ThinkPad-P72.home (unknown [50.45.173.55]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 4E3D22151B; Mon, 31 Aug 2020 18:11:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1598897484; bh=Md1F4JPJeRjrVLa/O8zZqOK+IKqCvmD2zTJEeJk3ut8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=jqEr/u1O+dXKVsOTUmIwBfv416WKGJi58bEDo6EiTwcjyI12RC70aPxu7VTqlSVyp Wj8chE+TKuUQQ7xBJ5SAjihTDcZtqoTZSVrHSWxFETZSDyObqQ078o7rid/JlcQahQ g8KrN2YZ3gP5VCqOHWa+sSnTVdEBVtuRtwclikww= From: paulmck@kernel.org To: rcu@vger.kernel.org Cc: linux-kernel@vger.kernel.org, kernel-team@fb.com, 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 13/13] rcu: Remove unused "cpu" parameter from rcu_report_qs_rdp() Date: Mon, 31 Aug 2020 11:11:20 -0700 Message-Id: <20200831181120.1044-13-paulmck@kernel.org> X-Mailer: git-send-email 2.9.5 In-Reply-To: <20200831181101.GA950@paulmck-ThinkPad-P72> References: <20200831181101.GA950@paulmck-ThinkPad-P72> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: "Paul E. McKenney" The "cpu" parameter to rcu_report_qs_rdp() is not used, with rdp->cpu being used instead. Furtheremore, every call to rcu_report_qs_rdp() invokes it on rdp->cpu. This commit therefore removes this unused "cpu" parameter and converts a check of rdp->cpu against smp_processor_id() to a WARN_ON_ONCE(). Reported-by: Jann Horn Signed-off-by: Paul E. McKenney --- kernel/rcu/tree.c | 8 ++++---- kernel/rcu/tree_plugin.h | 4 ++-- 2 files changed, 6 insertions(+), 6 deletions(-) diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index a295cadf..c612765 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -2240,7 +2240,7 @@ rcu_report_unblock_qs_rnp(struct rcu_node *rnp, unsigned long flags) * structure. This must be called from the specified CPU. */ static void -rcu_report_qs_rdp(int cpu, struct rcu_data *rdp) +rcu_report_qs_rdp(struct rcu_data *rdp) { unsigned long flags; unsigned long mask; @@ -2249,6 +2249,7 @@ rcu_report_qs_rdp(int cpu, struct rcu_data *rdp) rcu_segcblist_is_offloaded(&rdp->cblist); struct rcu_node *rnp; + WARN_ON_ONCE(rdp->cpu != smp_processor_id()); rnp = rdp->mynode; raw_spin_lock_irqsave_rcu_node(rnp, flags); if (rdp->cpu_no_qs.b.norm || rdp->gp_seq != rnp->gp_seq || @@ -2265,8 +2266,7 @@ rcu_report_qs_rdp(int cpu, struct rcu_data *rdp) return; } mask = rdp->grpmask; - if (rdp->cpu == smp_processor_id()) - rdp->core_needs_qs = false; + rdp->core_needs_qs = false; if ((rnp->qsmask & mask) == 0) { raw_spin_unlock_irqrestore_rcu_node(rnp, flags); } else { @@ -2315,7 +2315,7 @@ rcu_check_quiescent_state(struct rcu_data *rdp) * Tell RCU we are done (but rcu_report_qs_rdp() will be the * judge of that). */ - rcu_report_qs_rdp(rdp->cpu, rdp); + rcu_report_qs_rdp(rdp); } /* diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h index 25a676d..ca31be0 100644 --- a/kernel/rcu/tree_plugin.h +++ b/kernel/rcu/tree_plugin.h @@ -461,7 +461,7 @@ rcu_preempt_deferred_qs_irqrestore(struct task_struct *t, unsigned long flags) t->rcu_read_unlock_special.s = 0; if (special.b.need_qs) { if (IS_ENABLED(CONFIG_RCU_STRICT_GRACE_PERIOD)) { - rcu_report_qs_rdp(rdp->cpu, rdp); + rcu_report_qs_rdp(rdp); udelay(rcu_unlock_delay); } else { rcu_qs(); @@ -791,7 +791,7 @@ void rcu_read_unlock_strict(void) irqs_disabled() || preempt_count() || !rcu_state.gp_kthread) return; rdp = this_cpu_ptr(&rcu_data); - rcu_report_qs_rdp(rdp->cpu, rdp); + rcu_report_qs_rdp(rdp); udelay(rcu_unlock_delay); } EXPORT_SYMBOL_GPL(rcu_read_unlock_strict); -- 2.9.5