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=-19.7 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,USER_AGENT_GIT autolearn=unavailable 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 D5DEAC43461 for ; Tue, 11 May 2021 23:13:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B7F7B610F8 for ; Tue, 11 May 2021 23:13:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230197AbhEKXOM (ORCPT ); Tue, 11 May 2021 19:14:12 -0400 Received: from mail.kernel.org ([198.145.29.99]:48030 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230291AbhEKXNd (ORCPT ); Tue, 11 May 2021 19:13:33 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 6767561952; Tue, 11 May 2021 23:12:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1620774745; bh=z5Ue1qKxYKPogfXdLCoyPZEQoULfCVbxyQmjN0XplRM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=d745UZO5cevgy/t6JPgDCHxLsgkWF3Eu1+GovVpfRBRJbzC3W/KDTTBnpqaJz/TEV wPMQFni3Logk+AUzh8sA2KSrAozVarInPgEvt/+CZCdvbMDG3Er0iW5sTQW6t1F9C3 hxZYJoEu+GM+40Zo51xsDlOhlwIl3GVQffM6fJ6sZgTm+B/KLXBWK5itMNbnmxuiK2 DZCQSteOcUbajiNRytgO7lqBAJl8lf9ky+8XqMuly/7Jb80qxwT2rYrpjheKGbO57c N0C7XrkzT+rd/RTFq3dloBk7xAtglIilWkxDXsQhw64ukNguPdUjXTtjfc5rmkNZQz 6B9Z+O5vmlygA== Received: by paulmck-ThinkPad-P17-Gen-1.home (Postfix, from userid 1000) id 8C2E15C0E5C; Tue, 11 May 2021 16:12:24 -0700 (PDT) From: "Paul E. McKenney" 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" Subject: [PATCH tip/core/rcu 19/26] rcutorture: Make rcu_torture_boost_failed() check for GP end Date: Tue, 11 May 2021 16:12:16 -0700 Message-Id: <20210511231223.2895398-19-paulmck@kernel.org> X-Mailer: git-send-email 2.31.1.189.g2e36527f23 In-Reply-To: <20210511231149.GA2895263@paulmck-ThinkPad-P17-Gen-1> References: <20210511231149.GA2895263@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 It is possible that a delayed grace period that rcu_torture_boost() was polling for ended while rcu_torture_boost_failed() was printing the failure splat. It would be good to know when this happens. This commit therefore has rcu_torture_boost_failed() recheck the grace period after printing the splat, and printing a message indicating whether or not the grace period has ended. Signed-off-by: Paul E. McKenney --- kernel/rcu/rcutorture.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c index 31338b2d6609..02a14dfcae67 100644 --- a/kernel/rcu/rcutorture.c +++ b/kernel/rcu/rcutorture.c @@ -919,6 +919,7 @@ static void rcu_torture_enable_rt_throttle(void) static bool rcu_torture_boost_failed(unsigned long gp_state, unsigned long start, unsigned long end) { static int dbg_done; + bool gp_done; if (end - start > test_boost_duration * HZ - HZ / 2) { // Recheck after checking time to avoid false positives. @@ -931,6 +932,11 @@ static bool rcu_torture_boost_failed(unsigned long gp_state, unsigned long start pr_info("Boost inversion thread ->rt_priority %u gp_state %lu jiffies %lu\n", current->rt_priority, gp_state, end - start); cur_ops->gp_kthread_dbg(); + // Recheck after print to flag grace period ending during splat. + gp_done = cur_ops->poll_gp_state(gp_state); + pr_info("Boost inversion: GP %lu %s.\n", gp_state, + gp_done ? "ended already" : "still pending"); + } return true; // failed -- 2.31.1.189.g2e36527f23