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=-19.0 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 BE977C4321A for ; Thu, 4 Mar 2021 01:08:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8CD0264E7C for ; Thu, 4 Mar 2021 01:08:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1356442AbhCDBEt (ORCPT ); Wed, 3 Mar 2021 20:04:49 -0500 Received: from mail.kernel.org ([198.145.29.99]:54698 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1450997AbhCDAak (ORCPT ); Wed, 3 Mar 2021 19:30:40 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 6948964EBA; Thu, 4 Mar 2021 00:29:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1614817797; bh=hdLIi/GxehNgqRlNQtgUDCSTsM8C6t45OhCRDD7Yshc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=QNTofXqaqHClq6atqGh9Iad4PTUBU4dIj7Q0ADZo5xSnfjuGBTkHWkfVC/desEt6/ 1dLmo/jGVuD6OHMNdnB2PbKvl8X6bj4Bje0u4kX2cxOoaGtjqBF9i0TPxCWkKy8Dxq L7ULgq3nWk6OkJqBdIzbllvLy5YntuAhAYXuEdJZXdKhXwNGDhoag2QeFp7qAHp6Ue q4DPTgXcv6ky5PkgGcXKeJT6C7ixN24Wld1zVQB7gi3tjDKPmNGxpA0/oL9/uBChbH h9xMTWfqYTZXqz9VMJ07+AXSzZ4yA+wf4IDJrotZVMSNy3PtaOpUxKxvj4ZkTD66yr KfmdbmLSF/7SA== 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, 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 4/5] rcu: Make rcu_read_unlock_special() expedite strict grace periods Date: Wed, 3 Mar 2021 16:29:54 -0800 Message-Id: <20210304002955.24132-4-paulmck@kernel.org> X-Mailer: git-send-email 2.9.5 In-Reply-To: <20210304002919.GA24003@paulmck-ThinkPad-P72> References: <20210304002919.GA24003@paulmck-ThinkPad-P72> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: "Paul E. McKenney" In kernels built with CONFIG_RCU_STRICT_GRACE_PERIOD=y, every grace period is an expedited grace period. However, rcu_read_unlock_special() does not treat them that way, instead allowing the deferred quiescent state to be reported whenever. This commit therefore adds a check of this Kconfig option that causes rcu_read_unlock_special() to treat all grace periods as expedited for CONFIG_RCU_STRICT_GRACE_PERIOD=y kernels. Signed-off-by: Paul E. McKenney --- kernel/rcu/tree_plugin.h | 1 + 1 file changed, 1 insertion(+) diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h index e17cb23..a21c41c 100644 --- a/kernel/rcu/tree_plugin.h +++ b/kernel/rcu/tree_plugin.h @@ -615,6 +615,7 @@ static void rcu_read_unlock_special(struct task_struct *t) expboost = (t->rcu_blocked_node && READ_ONCE(t->rcu_blocked_node->exp_tasks)) || (rdp->grpmask & READ_ONCE(rnp->expmask)) || + IS_ENABLED(CONFIG_RCU_STRICT_GRACE_PERIOD) || (IS_ENABLED(CONFIG_RCU_BOOST) && irqs_were_disabled && t->rcu_blocked_node); // Need to defer quiescent state until everything is enabled. -- 2.9.5