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=-19.3 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 941ECC4332E for ; Wed, 6 Jan 2021 04:50:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5A2DE22D01 for ; Wed, 6 Jan 2021 04:50:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725879AbhAFEuS (ORCPT ); Tue, 5 Jan 2021 23:50:18 -0500 Received: from mail.kernel.org ([198.145.29.99]:33378 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726794AbhAFEuR (ORCPT ); Tue, 5 Jan 2021 23:50:17 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 1B02822D01; Wed, 6 Jan 2021 04:48:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1609908537; bh=UnD48NmW6BOlX27GwWs89YVapaipnYJPMncaS2Q2YQE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=OKzuZcQUV1iO1g+wQ1OOt91QT7LyxrNdR2suqblkc9yLEBsrp9CRuoXdtm9XmZL3F TidAqF0dCkXhcE0qIQq3FnuajjJHHGs9cpz5sFfp13mRt7KVQ0roKxIASUfmkIVhrM VEBTqgaooK1TzjCpN83vw+WOItZ2v2EpU0s4PLujehB97iNddRbwdY6y7v7gkvj9mn q2aPtdxkA1tMg47rj0P8yujyWihXIFurDw9BBO3Cl8fOqnYaz+twsuxABktezIYJ9l msLuIRkUxTTNP8jvghMSRj7sJlwnWYb3bvdmYo9U+LRuDdOi+wEal8sBorfm8uYe0w d746bjL/RRKpw== 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, Frederic Weisbecker , Neeraj Upadhyay , "Paul E . McKenney" Subject: [PATCH tip/core/rcu 11/21] rcu/nocb: Only cond_resched() from actual offloaded batch processing Date: Tue, 5 Jan 2021 20:48:43 -0800 Message-Id: <20210106044853.20812-11-paulmck@kernel.org> X-Mailer: git-send-email 2.9.5 In-Reply-To: <20210106013950.GA14663@paulmck-ThinkPad-P72> References: <20210106013950.GA14663@paulmck-ThinkPad-P72> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Frederic Weisbecker During a toggle operations, rcu_do_batch() may be invoked concurrently by softirqs and offloaded processing for a given CPU's callbacks. This commit therefore makes sure cond_resched() is invoked only from the offloaded context. Cc: Josh Triplett Cc: Steven Rostedt Cc: Mathieu Desnoyers Cc: Lai Jiangshan Cc: Joel Fernandes Cc: Neeraj Upadhyay Cc: Thomas Gleixner Inspired-by: Paul E. McKenney Tested-by: Boqun Feng Signed-off-by: Frederic Weisbecker Signed-off-by: Paul E. McKenney --- kernel/rcu/tree.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index 83362f6..4ef59a5 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -2516,8 +2516,7 @@ static void rcu_do_batch(struct rcu_data *rdp) /* Exceeded the time limit, so leave. */ break; } - if (offloaded) { - WARN_ON_ONCE(in_serving_softirq()); + if (!in_serving_softirq()) { local_bh_enable(); lockdep_assert_irqs_enabled(); cond_resched_tasks_rcu_qs(); -- 2.9.5