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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 18359C433EF for ; Thu, 13 Jan 2022 02:15:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231607AbiAMCPn (ORCPT ); Wed, 12 Jan 2022 21:15:43 -0500 Received: from ec2-13-52-33-57.us-west-1.compute.amazonaws.com ([13.52.33.57]:11533 "EHLO aurora.tech" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S231528AbiAMCPm (ORCPT ); Wed, 12 Jan 2022 21:15:42 -0500 Received: by aurora.tech (Postfix, from userid 1001) id 16EBF16402F4; Tue, 11 Jan 2022 15:33:17 -0800 (PST) From: Alison Chaiken To: tglx@linutronix.de Cc: peterz@infradead.org, paulmck@kernel.org, valentin.schneider@arm.com, frederic@kernel.org, linux-kernel@vger.kernel.org, glenn@aurora.tech, alison@she-devel.com, Alison Chaiken Subject: [PATCH 1/4] RCU: move kthread_prio bounds-check to a separate function Date: Tue, 11 Jan 2022 15:32:50 -0800 Message-Id: <20220111233253.21692-2-achaiken@aurora.tech> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20220111233253.21692-1-achaiken@aurora.tech> References: <20220111233253.21692-1-achaiken@aurora.tech> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Move the bounds-check of the kthread_prio cmdline parameter to a new function in order to faciliate a different callsite. Signed-off-by: Alison Chaiken --- kernel/rcu/tree.c | 39 +++++++++++++++++++++++---------------- 1 file changed, 23 insertions(+), 16 deletions(-) diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index 9a04550cc54b..15cabb288a1c 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -4404,26 +4404,10 @@ static int rcu_pm_notify(struct notifier_block *self, static int __init rcu_spawn_gp_kthread(void) { unsigned long flags; - int kthread_prio_in = kthread_prio; struct rcu_node *rnp; struct sched_param sp; struct task_struct *t; - /* Force priority into range. */ - if (IS_ENABLED(CONFIG_RCU_BOOST) && kthread_prio < 2 - && IS_BUILTIN(CONFIG_RCU_TORTURE_TEST)) - kthread_prio = 2; - else if (IS_ENABLED(CONFIG_RCU_BOOST) && kthread_prio < 1) - kthread_prio = 1; - else if (kthread_prio < 0) - kthread_prio = 0; - else if (kthread_prio > 99) - kthread_prio = 99; - - if (kthread_prio != kthread_prio_in) - pr_alert("rcu_spawn_gp_kthread(): Limited prio to %d from %d\n", - kthread_prio, kthread_prio_in); - rcu_scheduler_fully_active = 1; t = kthread_create(rcu_gp_kthread, NULL, "%s", rcu_state.name); if (WARN_ONCE(IS_ERR(t), "%s: Could not start grace-period kthread, OOM is now expected behavior\n", __func__)) @@ -4548,6 +4532,28 @@ static void __init rcu_init_one(void) } } +/* + * Force priority from the kernel command-line into range. + */ +static void __init sanitize_kthread_prio(void) +{ + int kthread_prio_in = kthread_prio; + + if (IS_ENABLED(CONFIG_RCU_BOOST) && kthread_prio < 2 + && IS_BUILTIN(CONFIG_RCU_TORTURE_TEST)) + kthread_prio = 2; + else if (IS_ENABLED(CONFIG_RCU_BOOST) && kthread_prio < 1) + kthread_prio = 1; + else if (kthread_prio < 0) + kthread_prio = 0; + else if (kthread_prio > 99) + kthread_prio = 99; + + if (kthread_prio != kthread_prio_in) + pr_alert("%s: Limited prio to %d from %d\n", + __func__, kthread_prio, kthread_prio_in); +} + /* * Compute the rcu_node tree geometry from kernel parameters. This cannot * replace the definitions in tree.h because those are needed to size @@ -4708,6 +4714,7 @@ void __init rcu_init(void) kfree_rcu_batch_init(); rcu_bootup_announce(); + sanitize_kthread_prio(); rcu_init_geometry(); rcu_init_one(); if (dump_tree) -- 2.32.0