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=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 73C8AC433E6 for ; Mon, 31 Aug 2020 18:03:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3E2902083E for ; Mon, 31 Aug 2020 18:03:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1598896987; bh=NHb/uTlI4XHsRb/k0hOwL2ogF8mCSlrEuc3/2RLkKwc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=VDjWKgc1xAlb70tfPpomZTHWfq0Lmpt19WLm4QgEenCIcAp3xnETPdMqVSxP+cN9W VAwRw+c3Tw7yKx6/rszENE2xzv1yWfdHIyUOaB5c/bnJ494cf64Lvpo8J09YMIZYjy ie4QmY5swa83+V5BGojxUu+4goPYVvWnnhfE0Glo= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729236AbgHaSDE (ORCPT ); Mon, 31 Aug 2020 14:03:04 -0400 Received: from mail.kernel.org ([198.145.29.99]:35758 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728829AbgHaSB0 (ORCPT ); Mon, 31 Aug 2020 14:01:26 -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 14BBD21582; Mon, 31 Aug 2020 18:01:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1598896886; bh=NHb/uTlI4XHsRb/k0hOwL2ogF8mCSlrEuc3/2RLkKwc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=kBPmO5/kGI8gApBVBahCdZgxKSWm5wQnN4i/V76N5DT9AdUokBFaTWrtKWjgmcwln 6pNXdmmrxbZh+8GUWBmvDAVGTtoEWjdjD3N/8jWn31bucAXC/0lpJtT2IhQJTSe0zx CCFiBgRVQukHJrJTskeT6Nx+RpxcE+sHSv6PZvA4= 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 18/24] rcu: Move rcu_cpu_started per-CPU variable to rcu_data Date: Mon, 31 Aug 2020 11:01:10 -0700 Message-Id: <20200831180116.32690-18-paulmck@kernel.org> X-Mailer: git-send-email 2.9.5 In-Reply-To: <20200831180050.GA32590@paulmck-ThinkPad-P72> References: <20200831180050.GA32590@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" When the rcu_cpu_started per-CPU variable was added by commit f64c6013a202 ("rcu/x86: Provide early rcu_cpu_starting() callback"), there were multiple sets of per-CPU rcu_data structures. Therefore, the rcu_cpu_started flag was added as a separate per-CPU variable. But now there is only one set of per-CPU rcu_data structures, so this commit moves rcu_cpu_started to a new ->cpu_started field in that structure. Signed-off-by: Paul E. McKenney --- kernel/rcu/tree.c | 11 ++++------- kernel/rcu/tree.h | 1 + 2 files changed, 5 insertions(+), 7 deletions(-) diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index da05afc..52108dd 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -3967,8 +3967,6 @@ int rcutree_offline_cpu(unsigned int cpu) return 0; } -static DEFINE_PER_CPU(int, rcu_cpu_started); - /* * Mark the specified CPU as being online so that subsequent grace periods * (both expedited and normal) will wait on it. Note that this means that @@ -3988,12 +3986,11 @@ void rcu_cpu_starting(unsigned int cpu) struct rcu_node *rnp; bool newcpu; - if (per_cpu(rcu_cpu_started, cpu)) + rdp = per_cpu_ptr(&rcu_data, cpu); + if (rdp->cpu_started) return; + rdp->cpu_started = true; - per_cpu(rcu_cpu_started, cpu) = 1; - - rdp = per_cpu_ptr(&rcu_data, cpu); rnp = rdp->mynode; mask = rdp->grpmask; raw_spin_lock_irqsave_rcu_node(rnp, flags); @@ -4053,7 +4050,7 @@ void rcu_report_dead(unsigned int cpu) raw_spin_unlock_irqrestore_rcu_node(rnp, flags); raw_spin_unlock(&rcu_state.ofl_lock); - per_cpu(rcu_cpu_started, cpu) = 0; + rdp->cpu_started = false; } /* diff --git a/kernel/rcu/tree.h b/kernel/rcu/tree.h index c96ae35..309bc7f 100644 --- a/kernel/rcu/tree.h +++ b/kernel/rcu/tree.h @@ -156,6 +156,7 @@ struct rcu_data { bool beenonline; /* CPU online at least once. */ bool gpwrap; /* Possible ->gp_seq wrap. */ bool exp_deferred_qs; /* This CPU awaiting a deferred QS? */ + bool cpu_started; /* RCU watching this onlining CPU. */ struct rcu_node *mynode; /* This CPU's leaf of hierarchy */ unsigned long grpmask; /* Mask to apply to leaf qsmask. */ unsigned long ticks_this_gp; /* The number of scheduling-clock */ -- 2.9.5