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 51172C43219 for ; Mon, 18 Apr 2022 22:54:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233424AbiDRW4w (ORCPT ); Mon, 18 Apr 2022 18:56:52 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44378 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233483AbiDRW4t (ORCPT ); Mon, 18 Apr 2022 18:56:49 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 627B92CE20; Mon, 18 Apr 2022 15:54:03 -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 779E161037; Mon, 18 Apr 2022 22:54:02 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 98C13C385B9; Mon, 18 Apr 2022 22:54:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1650322441; bh=hK5x6BVv25qP8BKNXoIb9LDR8AFOXkO1p5pr+bQzLFU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Maic1LuAc80j57STgy7M0pyeJzX0a0C1VVbSKtTsh+079xE+aljXM6mk7Hqsx6ECA NZjLS4axQBYrFAY34jG7MWH3loaP6nFvMDbUP81auvSKrwA/59Y6Je0ng4u04YcAwa re/pU06wwSXkeFGMS1QlTJME5q340n2ntNCBkd/SZwEicb7O8Nn23jQiR8/ZY7l+2i Uv/f4U56agz3e70dhA9hzBooMgAQ2F7JIOP3ZGFTCeEyTWiRIqg0GMcF14UFTEk12a wdhWcQrFf5ZP+HQSuSrIkwcVqP2LAe0ubWTJ2RVWnPFQ4anWYl2zlqRca7dAotBCvR x+QPnAl/OvL9w== Received: by paulmck-ThinkPad-P17-Gen-1.home (Postfix, from userid 1000) id EE8B15C12AB; Mon, 18 Apr 2022 15:54:00 -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 , "Paul E . McKenney" Subject: [PATCH rcu 09/11] rcu: Check for successful spawn of ->boost_kthread_task Date: Mon, 18 Apr 2022 15:53:57 -0700 Message-Id: <20220418225359.3945217-9-paulmck@kernel.org> X-Mailer: git-send-email 2.31.1.189.g2e36527f23 In-Reply-To: <20220418225345.GA3945110@paulmck-ThinkPad-P17-Gen-1> References: <20220418225345.GA3945110@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 From: Zqiang For the spawning of the priority-boost kthreads can fail, improbable though this might seem. This commit therefore refrains from attemoting to initiate RCU priority boosting when The ->boost_kthread_task pointer is NULL. Signed-off-by: Zqiang Signed-off-by: Paul E. McKenney --- kernel/rcu/tree_plugin.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h index 176639c6215f..5c23aceecd62 100644 --- a/kernel/rcu/tree_plugin.h +++ b/kernel/rcu/tree_plugin.h @@ -1125,7 +1125,8 @@ static void rcu_initiate_boost(struct rcu_node *rnp, unsigned long flags) __releases(rnp->lock) { raw_lockdep_assert_held_rcu_node(rnp); - if (!rcu_preempt_blocked_readers_cgp(rnp) && rnp->exp_tasks == NULL) { + if (!rnp->boost_kthread_task || + (!rcu_preempt_blocked_readers_cgp(rnp) && !rnp->exp_tasks)) { raw_spin_unlock_irqrestore_rcu_node(rnp, flags); return; } -- 2.31.1.189.g2e36527f23