From patchwork Mon Jun 20 22:45:01 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Paul E. McKenney" X-Patchwork-Id: 12888343 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 B0F64CCA480 for ; Mon, 20 Jun 2022 22:45:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S244425AbiFTWpI (ORCPT ); Mon, 20 Jun 2022 18:45:08 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49648 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S244163AbiFTWpH (ORCPT ); Mon, 20 Jun 2022 18:45:07 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4B41E19F8E; Mon, 20 Jun 2022 15:45:06 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id DBCCA61381; Mon, 20 Jun 2022 22:45:05 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 446A9C3411C; Mon, 20 Jun 2022 22:45:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1655765105; bh=XDrxmKz0bTXwZ0WpBKmpBvBfH5ezkcFLIoxVI2Soqag=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=LlL/btuFxDjEpX19ZQKfgM+uDaD57gGiZjBz3/2+SX/A7DnJpvlChtmTzrn5EbZet x2wuu+/8TYh38L63GcbRWVsqcF4aMz9mAsI9SZ12Q5XKBDlV9fbVFM7rqgWNDnXhB5 9ue9ih1dMMPpT4SFcM3jLdLUla1MAJDQsi1lF0rSGhreX0FGUQXMIzK0B2TOHE0Xd1 FroOnoKj9S01sWioYXusBx6eYfeYZRD7HpDz/WwVsERPYOcRlsCXbs0UDJn3n9qlgX 1Y9uvKdrzWMKIr1uOugigSgKKibs8o9+Ru1qVnh+wtjSMqdsTJXpNX8o8c3Y7Ym8C6 pKXlrGLx0+atg== Received: by paulmck-ThinkPad-P17-Gen-1.home (Postfix, from userid 1000) id EF8955C0ADC; Mon, 20 Jun 2022 15:45:04 -0700 (PDT) From: "Paul E. McKenney" To: rcu@vger.kernel.org Cc: linux-kernel@vger.kernel.org, kernel-team@fb.com, rostedt@goodmis.org, Zqiang , kernel test robot , "Paul E . McKenney" Subject: [PATCH rcu 5/7] rcu: Add nocb_cb_kthread check to rcu_is_callbacks_kthread() Date: Mon, 20 Jun 2022 15:45:01 -0700 Message-Id: <20220620224503.3841196-5-paulmck@kernel.org> X-Mailer: git-send-email 2.31.1.189.g2e36527f23 In-Reply-To: <20220620224455.GA3840881@paulmck-ThinkPad-P17-Gen-1> References: <20220620224455.GA3840881@paulmck-ThinkPad-P17-Gen-1> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: rcu@vger.kernel.org From: Zqiang Callbacks are invoked in RCU kthreads when calbacks are offloaded (rcu_nocbs boot parameter) or when RCU's softirq handler has been offloaded to rcuc kthreads (use_softirq==0). The current code allows for the rcu_nocbs case but not the use_softirq case. This commit adds support for the use_softirq case. Reported-by: kernel test robot Signed-off-by: Zqiang Signed-off-by: Paul E. McKenney Reviewed-by: Neeraj Upadhyay --- kernel/rcu/tree.c | 4 ++-- kernel/rcu/tree.h | 2 +- kernel/rcu/tree_plugin.h | 33 +++++++++++++++++++-------------- 3 files changed, 22 insertions(+), 17 deletions(-) diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index c25ba442044a6..74455671e6cf2 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -2530,7 +2530,7 @@ static void rcu_do_batch(struct rcu_data *rdp) trace_rcu_batch_end(rcu_state.name, 0, !rcu_segcblist_empty(&rdp->cblist), need_resched(), is_idle_task(current), - rcu_is_callbacks_kthread()); + rcu_is_callbacks_kthread(rdp)); return; } @@ -2608,7 +2608,7 @@ static void rcu_do_batch(struct rcu_data *rdp) rcu_nocb_lock_irqsave(rdp, flags); rdp->n_cbs_invoked += count; trace_rcu_batch_end(rcu_state.name, count, !!rcl.head, need_resched(), - is_idle_task(current), rcu_is_callbacks_kthread()); + is_idle_task(current), rcu_is_callbacks_kthread(rdp)); /* Update counts and requeue any remaining callbacks. */ rcu_segcblist_insert_done_cbs(&rdp->cblist, &rcl); diff --git a/kernel/rcu/tree.h b/kernel/rcu/tree.h index 4f8532c33558f..649ad4f0129b1 100644 --- a/kernel/rcu/tree.h +++ b/kernel/rcu/tree.h @@ -426,7 +426,7 @@ static void rcu_flavor_sched_clock_irq(int user); static void dump_blkd_tasks(struct rcu_node *rnp, int ncheck); static void rcu_initiate_boost(struct rcu_node *rnp, unsigned long flags); static void rcu_preempt_boost_start_gp(struct rcu_node *rnp); -static bool rcu_is_callbacks_kthread(void); +static bool rcu_is_callbacks_kthread(struct rcu_data *rdp); static void rcu_cpu_kthread_setup(unsigned int cpu); static void rcu_spawn_one_boost_kthread(struct rcu_node *rnp); static bool rcu_preempt_has_tasks(struct rcu_node *rnp); diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h index c8ba0fe17267c..0483e1338c413 100644 --- a/kernel/rcu/tree_plugin.h +++ b/kernel/rcu/tree_plugin.h @@ -1012,6 +1012,25 @@ static void rcu_cpu_kthread_setup(unsigned int cpu) WRITE_ONCE(rdp->rcuc_activity, jiffies); } +static bool rcu_is_callbacks_nocb_kthread(struct rcu_data *rdp) +{ +#ifdef CONFIG_RCU_NOCB_CPU + return rdp->nocb_cb_kthread == current; +#else + return false; +#endif +} + +/* + * Is the current CPU running the RCU-callbacks kthread? + * Caller must have preemption disabled. + */ +static bool rcu_is_callbacks_kthread(struct rcu_data *rdp) +{ + return rdp->rcu_cpu_kthread_task == current || + rcu_is_callbacks_nocb_kthread(rdp); +} + #ifdef CONFIG_RCU_BOOST /* @@ -1151,15 +1170,6 @@ static void rcu_initiate_boost(struct rcu_node *rnp, unsigned long flags) } } -/* - * Is the current CPU running the RCU-callbacks kthread? - * Caller must have preemption disabled. - */ -static bool rcu_is_callbacks_kthread(void) -{ - return __this_cpu_read(rcu_data.rcu_cpu_kthread_task) == current; -} - #define RCU_BOOST_DELAY_JIFFIES DIV_ROUND_UP(CONFIG_RCU_BOOST_DELAY * HZ, 1000) /* @@ -1242,11 +1252,6 @@ static void rcu_initiate_boost(struct rcu_node *rnp, unsigned long flags) raw_spin_unlock_irqrestore_rcu_node(rnp, flags); } -static bool rcu_is_callbacks_kthread(void) -{ - return false; -} - static void rcu_preempt_boost_start_gp(struct rcu_node *rnp) { }