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=-19.2 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,URIBL_BLOCKED,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 0AAA1C4332B for ; Wed, 20 Jan 2021 04:33:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CD9172313B for ; Wed, 20 Jan 2021 04:33:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729096AbhATEdb (ORCPT ); Tue, 19 Jan 2021 23:33:31 -0500 Received: from mail.kernel.org ([198.145.29.99]:53508 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728538AbhATEdT (ORCPT ); Tue, 19 Jan 2021 23:33:19 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id A21C32332B; Wed, 20 Jan 2021 04:32:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1611117159; bh=C2eCzqPlT6BpIIK6gpaGBighn/FNw3gd4qUeJ00kb6I=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=sqbv/AxDOn1jEDC5ESSTjZLSC+xh4Fl7Fi8ZP3ADBgzOxW3K2pjUNsmBRMiII9qSU k+dkDB9Na6Bl97V79Wgxk0AKT9eaJgeAtxo/d7ivDTtIFH4VTuwPZ9bWmAbvYVB7Po 1bv9r1Fu7x0Lw9ZF8PgEhpV5Wh6EN8yvshw4vo9OWSaS9fgaleRqmsiPysBsFaB8nC OWKyrC5ojnnSi//LWBkg+cNJnCbaefhKvyhwvsfGAmrXRbXP3eKOh3rlp5c6orv0t7 88F8kx7DCbA1CzMTqIIgO9Hm2sGO+Z5WxzaDopT+nwg+gUxnlaiOHwbuZvtVWDatWK 0ayuo1UznURuA== 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" , Sebastian Andrzej Siewior , Scott Wood Subject: [PATCH tip/core/rcu 3/4] rcu: Run rcuo kthreads at elevated priority in CONFIG_RCU_BOOST kernels Date: Tue, 19 Jan 2021 20:32:35 -0800 Message-Id: <20210120043236.7254-3-paulmck@kernel.org> X-Mailer: git-send-email 2.9.5 In-Reply-To: <20210120043144.GA7045@paulmck-ThinkPad-P72> References: <20210120043144.GA7045@paulmck-ThinkPad-P72> Precedence: bulk List-ID: X-Mailing-List: rcu@vger.kernel.org From: "Paul E. McKenney" The priority level of the rcuo kthreads is the system administrator's responsibility, but kernels that priority-boost RCU readers probably need the rcuo kthreads running at the rcutree.kthread_prio level. This commit therefore sets these kthreads to that priority level at creation time, providing a sensible default. The system administrator is free to adjust as needed at any time. Cc: Sebastian Andrzej Siewior Cc: Scott Wood Cc: Thomas Gleixner Signed-off-by: Paul E. McKenney --- kernel/rcu/tree_plugin.h | 2 ++ 1 file changed, 2 insertions(+) diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h index fca31c6..7e33dae0 100644 --- a/kernel/rcu/tree_plugin.h +++ b/kernel/rcu/tree_plugin.h @@ -2197,6 +2197,7 @@ static int rcu_nocb_gp_kthread(void *arg) { struct rcu_data *rdp = arg; + rcu_cpu_kthread_setup(-1); for (;;) { WRITE_ONCE(rdp->nocb_gp_loops, rdp->nocb_gp_loops + 1); nocb_gp_wait(rdp); @@ -2298,6 +2299,7 @@ static int rcu_nocb_cb_kthread(void *arg) // Each pass through this loop does one callback batch, and, // if there are no more ready callbacks, waits for them. + rcu_cpu_kthread_setup(-1); for (;;) { nocb_cb_wait(rdp); cond_resched_tasks_rcu_qs(); -- 2.9.5