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=-19.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,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 07C28C433EF for ; Wed, 15 Sep 2021 23:34:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DE8FA61242 for ; Wed, 15 Sep 2021 23:34:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233222AbhIOXff (ORCPT ); Wed, 15 Sep 2021 19:35:35 -0400 Received: from mail.kernel.org ([198.145.29.99]:60462 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232935AbhIOXfE (ORCPT ); Wed, 15 Sep 2021 19:35:04 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 44DDF61212; Wed, 15 Sep 2021 23:33:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1631748825; bh=+hj63Mjsm9/ZDQadWxfRWJSN0LT4l+ZeTY9+sSnyZZs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=bPWbsWdxR0VqxPHGzpSyHV3v/DYjqwBARqN48OFCWTzQ2VUlYq87qxAKKkW3lqxsC 3D4sM+dVwegf5PI5yfqIGD+MawMWv/uf3t2QkXrjRq9dgiXE0B407zgLkkqiUZnwbd QCv4XGMq7GfM28+htSaAqOlzopBGejav4NarCM+7R3GYm3j4hVVc+ks0dm4vbBo3hZ NA0AbP3WrLqhfWqpS7hWrIcuI/HKvKHefqGJ0vWKo7KfCYpjqCP7w+LKyOFzWpyfO8 WbWVtKQaRo2Om4kaLDV0Eul1pxwBb9AwtLr4Vx54H6a5UOCH7t/FY5AX9rVNjI59DH jVLTXcTxrdWfg== Received: by paulmck-ThinkPad-P17-Gen-1.home (Postfix, from userid 1000) id CAAF75C0B1B; Wed, 15 Sep 2021 16:33:44 -0700 (PDT) From: "Paul E. McKenney" To: rcu@vger.kernel.org Cc: linux-kernel@vger.kernel.org, kernel-team@fb.com, mingo@kernel.org, jiangshanlai@gmail.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 rcu 09/14] rcu: Simplify rcu_report_dead() call to rcu_report_exp_rdp() Date: Wed, 15 Sep 2021 16:33:38 -0700 Message-Id: <20210915233343.3906738-9-paulmck@kernel.org> X-Mailer: git-send-email 2.31.1.189.g2e36527f23 In-Reply-To: <20210915233305.GA3906641@paulmck-ThinkPad-P17-Gen-1> References: <20210915233305.GA3906641@paulmck-ThinkPad-P17-Gen-1> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Currently, rcu_report_dead() disables preemption across its call to rcu_report_exp_rdp(), but this is pointless because interrupts are already disabled by the caller. In addition, rcu_report_dead() computes the address of the outgoing CPU's rcu_data structure, which is also pointless because this address is already present in local variable rdp. This commit therefore drops the preemption disabling and passes rdp to rcu_report_exp_rdp(). Signed-off-by: Paul E. McKenney --- kernel/rcu/tree.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index 801075e36515..dc2968473593 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -4294,9 +4294,7 @@ void rcu_report_dead(unsigned int cpu) do_nocb_deferred_wakeup(rdp); /* QS for any half-done expedited grace period. */ - preempt_disable(); - rcu_report_exp_rdp(this_cpu_ptr(&rcu_data)); - preempt_enable(); + rcu_report_exp_rdp(rdp); rcu_preempt_deferred_qs(current); /* Remove outgoing CPU from mask in the leaf rcu_node structure. */ -- 2.31.1.189.g2e36527f23